From e07dc7098cc80a6f1007968d1a9cdaae2974060f Mon Sep 17 00:00:00 2001
From: Simon Brooke <simon@journeyman.cc>
Date: Sun, 31 May 2020 11:44:09 +0100
Subject: [PATCH] Cloverage/ Kibit now working again

There was an - unterminated function in svg.clj, now removed.
---
 docs/cloverage/index.html                     | 219 ++++---
 docs/cloverage/walkmap/edge.clj.html          | 394 +++++-------
 docs/cloverage/walkmap/id.clj.html            |  32 +
 docs/cloverage/walkmap/ocean.clj.html         |   6 +-
 docs/cloverage/walkmap/path.clj.html          | 352 +++++-----
 docs/cloverage/walkmap/polygon.clj.html       | 238 ++++++-
 docs/cloverage/walkmap/read_svg.clj.html      | 299 +++++++++
 docs/cloverage/walkmap/routing.clj.html       |  62 ++
 docs/cloverage/walkmap/stl.clj.html           | 601 ++++++++++--------
 .../cloverage/walkmap/superstructure.clj.html | 596 ++++++++++++-----
 docs/cloverage/walkmap/svg.clj.html           | 214 ++++---
 docs/cloverage/walkmap/tag.clj.html           | 239 +++----
 docs/cloverage/walkmap/utils.clj.html         | 128 +++-
 docs/cloverage/walkmap/vertex.clj.html        | 388 ++++++-----
 project.clj                                   |   2 +-
 src/walkmap/routing.clj                       |   2 +-
 src/walkmap/stl.clj                           |   1 +
 src/walkmap/svg.clj                           |   6 -
 src/walkmap/vertex.clj                        |   3 +-
 test/walkmap/core_test.clj                    |   7 -
 .../{geometry_test.clj => utils_test.clj}     |   4 +-
 21 files changed, 2446 insertions(+), 1347 deletions(-)
 create mode 100644 docs/cloverage/walkmap/id.clj.html
 create mode 100644 docs/cloverage/walkmap/read_svg.clj.html
 create mode 100644 docs/cloverage/walkmap/routing.clj.html
 delete mode 100644 test/walkmap/core_test.clj
 rename test/walkmap/{geometry_test.clj => utils_test.clj} (88%)

diff --git a/docs/cloverage/index.html b/docs/cloverage/index.html
index f5c20a4..046068e 100644
--- a/docs/cloverage/index.html
+++ b/docs/cloverage/index.html
@@ -14,17 +14,6 @@
 <td class="with-number">Lines %</td>
 <td class="with-number">Total</td><td class="with-number">Blank</td><td class="with-number">Instrumented</td>
    </tr></thead>
-<tr>
- <td><a href="walkmap/core.clj.html">walkmap.core</a></td><td class="with-bar"><div class="covered"
-                                style="width:100.0%;
-                                        float:left;"> 1 </div></td>
-<td class="with-number">100.00 %</td>
-<td class="with-bar"><div class="covered"
-                                style="width:100.0%;
-                                        float:left;"> 1 </div></td>
-<td class="with-number">100.00 %</td>
-<td class="with-number">9</td><td class="with-number">1</td><td class="with-number">1</td>
-</tr>
 <tr>
  <td><a href="walkmap/edge.clj.html">walkmap.edge</a></td><td class="with-bar"><div class="covered"
                                 style="width:98.31697054698458%;
@@ -38,95 +27,127 @@
                                 style="width:4.8076923076923075%;
                                         float:left;"> 5 </div></td>
 <td class="with-number">100.00 %</td>
-<td class="with-number">189</td><td class="with-number">18</td><td class="with-number">104</td>
+<td class="with-number">175</td><td class="with-number">17</td><td class="with-number">104</td>
 </tr>
 <tr>
- <td><a href="walkmap/geometry.clj.html">walkmap.geometry</a></td><td class="with-bar"><div class="covered"
+ <td><a href="walkmap/id.clj.html">walkmap.id</a></td><td class="with-bar"><div class="covered"
                                 style="width:100.0%;
-                                        float:left;"> 62 </div></td>
+                                        float:left;"> 3 </div></td>
 <td class="with-number">100.00 %</td>
 <td class="with-bar"><div class="covered"
                                 style="width:100.0%;
-                                        float:left;"> 10 </div></td>
+                                        float:left;"> 2 </div></td>
 <td class="with-number">100.00 %</td>
-<td class="with-number">17</td><td class="with-number">1</td><td class="with-number">10</td>
+<td class="with-number">8</td><td class="with-number">2</td><td class="with-number">2</td>
 </tr>
 <tr>
  <td><a href="walkmap/ocean.clj.html">walkmap.ocean</a></td><td class="with-bar"><div class="covered"
-                                style="width:17.857142857142858%;
-                                        float:left;"> 5 </div><div class="not-covered"
-                                style="width:82.14285714285714%;
-                                        float:left;"> 23 </div></td>
-<td class="with-number">17.86 %</td>
+                                style="width:64.28571428571429%;
+                                        float:left;"> 18 </div><div class="not-covered"
+                                style="width:35.714285714285715%;
+                                        float:left;"> 10 </div></td>
+<td class="with-number">64.29 %</td>
 <td class="with-bar"><div class="covered"
-                                style="width:50.0%;
-                                        float:left;"> 4 </div><div class="not-covered"
-                                style="width:50.0%;
-                                        float:left;"> 4 </div></td>
-<td class="with-number">50.00 %</td>
+                                style="width:87.5%;
+                                        float:left;"> 7 </div><div class="not-covered"
+                                style="width:12.5%;
+                                        float:left;"> 1 </div></td>
+<td class="with-number">87.50 %</td>
 <td class="with-number">24</td><td class="with-number">4</td><td class="with-number">8</td>
 </tr>
 <tr>
  <td><a href="walkmap/path.clj.html">walkmap.path</a></td><td class="with-bar"><div class="covered"
-                                style="width:3.5294117647058822%;
-                                        float:left;"> 6 </div><div class="not-covered"
-                                style="width:96.47058823529412%;
-                                        float:left;"> 164 </div></td>
-<td class="with-number">3.53 %</td>
+                                style="width:12.041884816753926%;
+                                        float:left;"> 23 </div><div class="not-covered"
+                                style="width:87.95811518324608%;
+                                        float:left;"> 168 </div></td>
+<td class="with-number">12.04 %</td>
 <td class="with-bar"><div class="covered"
-                                style="width:15.789473684210526%;
-                                        float:left;"> 6 </div><div class="not-covered"
-                                style="width:84.21052631578948%;
-                                        float:left;"> 32 </div></td>
-<td class="with-number">15.79 %</td>
-<td class="with-number">78</td><td class="with-number">7</td><td class="with-number">38</td>
+                                style="width:17.94871794871795%;
+                                        float:left;"> 7 </div><div class="partial"
+                                style="width:2.5641025641025643%;
+                                        float:left;"> 1 </div><div class="not-covered"
+                                style="width:79.48717948717949%;
+                                        float:left;"> 31 </div></td>
+<td class="with-number">20.51 %</td>
+<td class="with-number">84</td><td class="with-number">7</td><td class="with-number">39</td>
 </tr>
 <tr>
  <td><a href="walkmap/polygon.clj.html">walkmap.polygon</a></td><td class="with-bar"><div class="covered"
-                                style="width:90.56603773584905%;
-                                        float:left;"> 48 </div><div class="not-covered"
-                                style="width:9.433962264150944%;
-                                        float:left;"> 5 </div></td>
-<td class="with-number">90.57 %</td>
+                                style="width:72.42647058823529%;
+                                        float:left;"> 197 </div><div class="not-covered"
+                                style="width:27.573529411764707%;
+                                        float:left;"> 75 </div></td>
+<td class="with-number">72.43 %</td>
 <td class="with-bar"><div class="covered"
-                                style="width:90.0%;
-                                        float:left;"> 9 </div><div class="partial"
+                                style="width:64.0%;
+                                        float:left;"> 32 </div><div class="partial"
                                 style="width:10.0%;
+                                        float:left;"> 5 </div><div class="not-covered"
+                                style="width:26.0%;
+                                        float:left;"> 13 </div></td>
+<td class="with-number">74.00 %</td>
+<td class="with-number">87</td><td class="with-number">8</td><td class="with-number">50</td>
+</tr>
+<tr>
+ <td><a href="walkmap/read_svg.clj.html">walkmap.read-svg</a></td><td class="with-bar"><div class="covered"
+                                style="width:2.857142857142857%;
+                                        float:left;"> 7 </div><div class="not-covered"
+                                style="width:97.14285714285714%;
+                                        float:left;"> 238 </div></td>
+<td class="with-number">2.86 %</td>
+<td class="with-bar"><div class="covered"
+                                style="width:15.217391304347826%;
+                                        float:left;"> 7 </div><div class="not-covered"
+                                style="width:84.78260869565217%;
+                                        float:left;"> 39 </div></td>
+<td class="with-number">15.22 %</td>
+<td class="with-number">97</td><td class="with-number">6</td><td class="with-number">46</td>
+</tr>
+<tr>
+ <td><a href="walkmap/routing.clj.html">walkmap.routing</a></td><td class="with-bar"><div class="covered"
+                                style="width:100.0%;
                                         float:left;"> 1 </div></td>
 <td class="with-number">100.00 %</td>
-<td class="with-number">19</td><td class="with-number">3</td><td class="with-number">10</td>
+<td class="with-bar"><div class="covered"
+                                style="width:100.0%;
+                                        float:left;"> 1 </div></td>
+<td class="with-number">100.00 %</td>
+<td class="with-number">18</td><td class="with-number">2</td><td class="with-number">1</td>
 </tr>
 <tr>
  <td><a href="walkmap/stl.clj.html">walkmap.stl</a></td><td class="with-bar"><div class="covered"
-                                style="width:56.777996070726914%;
-                                        float:left;"> 289 </div><div class="not-covered"
-                                style="width:43.222003929273086%;
-                                        float:left;"> 220 </div></td>
-<td class="with-number">56.78 %</td>
+                                style="width:49.07216494845361%;
+                                        float:left;"> 238 </div><div class="not-covered"
+                                style="width:50.92783505154639%;
+                                        float:left;"> 247 </div></td>
+<td class="with-number">49.07 %</td>
 <td class="with-bar"><div class="covered"
-                                style="width:44.0%;
-                                        float:left;"> 44 </div><div class="partial"
-                                style="width:10.0%;
+                                style="width:40.56603773584906%;
+                                        float:left;"> 43 </div><div class="partial"
+                                style="width:9.433962264150944%;
                                         float:left;"> 10 </div><div class="not-covered"
-                                style="width:46.0%;
-                                        float:left;"> 46 </div></td>
-<td class="with-number">54.00 %</td>
-<td class="with-number">191</td><td class="with-number">14</td><td class="with-number">100</td>
+                                style="width:50.0%;
+                                        float:left;"> 53 </div></td>
+<td class="with-number">50.00 %</td>
+<td class="with-number">206</td><td class="with-number">16</td><td class="with-number">106</td>
 </tr>
 <tr>
  <td><a href="walkmap/superstructure.clj.html">walkmap.superstructure</a></td><td class="with-bar"><div class="covered"
-                                style="width:2.5974025974025974%;
-                                        float:left;"> 4 </div><div class="not-covered"
-                                style="width:97.40259740259741%;
-                                        float:left;"> 150 </div></td>
-<td class="with-number">2.60 %</td>
+                                style="width:71.76781002638522%;
+                                        float:left;"> 272 </div><div class="not-covered"
+                                style="width:28.232189973614776%;
+                                        float:left;"> 107 </div></td>
+<td class="with-number">71.77 %</td>
 <td class="with-bar"><div class="covered"
-                                style="width:14.814814814814815%;
-                                        float:left;"> 4 </div><div class="not-covered"
-                                style="width:85.18518518518519%;
-                                        float:left;"> 23 </div></td>
-<td class="with-number">14.81 %</td>
-<td class="with-number">85</td><td class="with-number">9</td><td class="with-number">27</td>
+                                style="width:71.26436781609195%;
+                                        float:left;"> 62 </div><div class="partial"
+                                style="width:3.4482758620689653%;
+                                        float:left;"> 3 </div><div class="not-covered"
+                                style="width:25.28735632183908%;
+                                        float:left;"> 22 </div></td>
+<td class="with-number">74.71 %</td>
+<td class="with-number">183</td><td class="with-number">18</td><td class="with-number">87</td>
 </tr>
 <tr>
  <td><a href="walkmap/svg.clj.html">walkmap.svg</a></td><td class="with-bar"><div class="covered"
@@ -141,56 +162,58 @@
                                 style="width:87.87878787878788%;
                                         float:left;"> 58 </div></td>
 <td class="with-number">12.12 %</td>
-<td class="with-number">108</td><td class="with-number">7</td><td class="with-number">66</td>
+<td class="with-number">110</td><td class="with-number">7</td><td class="with-number">66</td>
 </tr>
 <tr>
  <td><a href="walkmap/tag.clj.html">walkmap.tag</a></td><td class="with-bar"><div class="covered"
                                 style="width:100.0%;
-                                        float:left;"> 137 </div></td>
+                                        float:left;"> 181 </div></td>
 <td class="with-number">100.00 %</td>
 <td class="with-bar"><div class="covered"
                                 style="width:100.0%;
-                                        float:left;"> 36 </div></td>
+                                        float:left;"> 34 </div></td>
 <td class="with-number">100.00 %</td>
-<td class="with-number">65</td><td class="with-number">7</td><td class="with-number">36</td>
+<td class="with-number">68</td><td class="with-number">8</td><td class="with-number">34</td>
 </tr>
 <tr>
  <td><a href="walkmap/utils.clj.html">walkmap.utils</a></td><td class="with-bar"><div class="covered"
-                                style="width:7.894736842105263%;
-                                        float:left;"> 3 </div><div class="not-covered"
-                                style="width:92.10526315789474%;
-                                        float:left;"> 35 </div></td>
-<td class="with-number">7.89 %</td>
+                                style="width:76.66666666666667%;
+                                        float:left;"> 92 </div><div class="not-covered"
+                                style="width:23.333333333333332%;
+                                        float:left;"> 28 </div></td>
+<td class="with-number">76.67 %</td>
 <td class="with-bar"><div class="covered"
-                                style="width:30.0%;
-                                        float:left;"> 3 </div><div class="not-covered"
-                                style="width:70.0%;
-                                        float:left;"> 7 </div></td>
-<td class="with-number">30.00 %</td>
-<td class="with-number">23</td><td class="with-number">3</td><td class="with-number">10</td>
+                                style="width:80.0%;
+                                        float:left;"> 16 </div><div class="partial"
+                                style="width:5.0%;
+                                        float:left;"> 1 </div><div class="not-covered"
+                                style="width:15.0%;
+                                        float:left;"> 3 </div></td>
+<td class="with-number">85.00 %</td>
+<td class="with-number">43</td><td class="with-number">4</td><td class="with-number">20</td>
 </tr>
 <tr>
  <td><a href="walkmap/vertex.clj.html">walkmap.vertex</a></td><td class="with-bar"><div class="covered"
-                                style="width:78.08641975308642%;
-                                        float:left;"> 253 </div><div class="not-covered"
-                                style="width:21.91358024691358%;
-                                        float:left;"> 71 </div></td>
-<td class="with-number">78.09 %</td>
+                                style="width:66.52078774617068%;
+                                        float:left;"> 304 </div><div class="not-covered"
+                                style="width:33.479212253829324%;
+                                        float:left;"> 153 </div></td>
+<td class="with-number">66.52 %</td>
 <td class="with-bar"><div class="covered"
-                                style="width:70.0%;
-                                        float:left;"> 42 </div><div class="partial"
-                                style="width:10.0%;
-                                        float:left;"> 6 </div><div class="not-covered"
-                                style="width:20.0%;
-                                        float:left;"> 12 </div></td>
-<td class="with-number">80.00 %</td>
-<td class="with-number">114</td><td class="with-number">11</td><td class="with-number">60</td>
+                                style="width:59.75609756097561%;
+                                        float:left;"> 49 </div><div class="partial"
+                                style="width:10.975609756097562%;
+                                        float:left;"> 9 </div><div class="not-covered"
+                                style="width:29.26829268292683%;
+                                        float:left;"> 24 </div></td>
+<td class="with-number">70.73 %</td>
+<td class="with-number">148</td><td class="with-number">13</td><td class="with-number">82</td>
 </tr>
 <tr><td>Totals:</td>
 <td class="with-bar"></td>
-<td class="with-number">61.24 %</td>
+<td class="with-number">60.81 %</td>
 <td class="with-bar"></td>
-<td class="with-number">61.28 %</td>
+<td class="with-number">62.17 %</td>
    </tr>
   </table>
  </body>
diff --git a/docs/cloverage/walkmap/edge.clj.html b/docs/cloverage/walkmap/edge.clj.html
index 7f17b26..6d8db3e 100644
--- a/docs/cloverage/walkmap/edge.clj.html
+++ b/docs/cloverage/walkmap/edge.clj.html
@@ -20,556 +20,514 @@
                 005&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.math.numeric-tower&nbsp;:as&nbsp;m]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:refer&nbsp;[polygon?]]
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[ensure2d&nbsp;ensure3d&nbsp;vertex&nbsp;vertex=&nbsp;vertex?]]))
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[ensure2d&nbsp;ensure3d&nbsp;vertex&nbsp;vertex=&nbsp;vertex?]]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                008&nbsp;&nbsp;
+                007&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                009&nbsp;&nbsp;(defn&nbsp;edge
+                008&nbsp;&nbsp;(defn&nbsp;edge
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                010&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;edge&nbsp;between&nbsp;vertices&nbsp;`v1`&nbsp;and&nbsp;`v2`.&quot;
+                009&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;edge&nbsp;between&nbsp;vertices&nbsp;`v1`&nbsp;and&nbsp;`v2`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;[v1&nbsp;v2]
+                010&nbsp;&nbsp;&nbsp;&nbsp;[v1&nbsp;v2]
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;(if
+                011&nbsp;&nbsp;&nbsp;&nbsp;(if
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(vertex?&nbsp;v1)&nbsp;(vertex?&nbsp;v2))
+                012&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(vertex?&nbsp;v1)&nbsp;(vertex?&nbsp;v2))
                 </span><br/>
 <span class="covered" title="13 out of 13 forms covered">
-                014&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:kind&nbsp;:edge&nbsp;:id&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;edge&quot;))&nbsp;:start&nbsp;v1&nbsp;:end&nbsp;v2}
+                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:kind&nbsp;:edge&nbsp;:walkmap.id&#x2F;id&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;edge&quot;))&nbsp;:start&nbsp;v1&nbsp;:end&nbsp;v2}
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                015&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Must&nbsp;be&nbsp;vertices.&quot;))))
+                014&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Must&nbsp;be&nbsp;vertices.&quot;))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                016&nbsp;&nbsp;
+                015&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                017&nbsp;&nbsp;(defn&nbsp;edge?
+                016&nbsp;&nbsp;(defn&nbsp;edge?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                018&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;edge.&nbsp;An&nbsp;edge&nbsp;shall&nbsp;be&nbsp;a&nbsp;map
+                017&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;edge.&nbsp;An&nbsp;edge&nbsp;shall&nbsp;be&nbsp;a&nbsp;map
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                019&nbsp;&nbsp;&nbsp;&nbsp;having&nbsp;the&nbsp;keys&nbsp;`:start`&nbsp;and&nbsp;`:end`,&nbsp;such&nbsp;that&nbsp;the&nbsp;values&nbsp;of&nbsp;each&nbsp;of&nbsp;those
+                018&nbsp;&nbsp;&nbsp;&nbsp;having&nbsp;the&nbsp;keys&nbsp;`:start`&nbsp;and&nbsp;`:end`,&nbsp;such&nbsp;that&nbsp;the&nbsp;values&nbsp;of&nbsp;each&nbsp;of&nbsp;those
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                020&nbsp;&nbsp;&nbsp;&nbsp;keys&nbsp;shall&nbsp;be&nbsp;a&nbsp;vertex.&quot;
+                019&nbsp;&nbsp;&nbsp;&nbsp;keys&nbsp;shall&nbsp;be&nbsp;a&nbsp;vertex.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                021&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                020&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                022&nbsp;&nbsp;&nbsp;&nbsp;(and
+                021&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
+                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(:start&nbsp;o))
+                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(:start&nbsp;o))
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                025&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(:end&nbsp;o))))
+                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(:end&nbsp;o))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                026&nbsp;&nbsp;
+                025&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                027&nbsp;&nbsp;(defn&nbsp;length
+                026&nbsp;&nbsp;(defn&nbsp;length
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                028&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;length&nbsp;of&nbsp;the&nbsp;edge&nbsp;`e`.&quot;
+                027&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;length&nbsp;of&nbsp;the&nbsp;edge&nbsp;`e`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                029&nbsp;&nbsp;&nbsp;&nbsp;[e]
+                028&nbsp;&nbsp;&nbsp;&nbsp;[e]
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                030&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[start&nbsp;(ensure3d&nbsp;(:start&nbsp;e))
+                029&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[start&nbsp;(ensure3d&nbsp;(:start&nbsp;e))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;end&nbsp;(ensure3d&nbsp;(:end&nbsp;e))]
+                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;end&nbsp;(ensure3d&nbsp;(:end&nbsp;e))]
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                032&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(m&#x2F;sqrt
+                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(m&#x2F;sqrt
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                033&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce
+                032&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                034&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;+
+                033&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;+
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                035&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                034&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="covered" title="11 out of 11 forms covered">
-                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(m&#x2F;expt&nbsp;(-&nbsp;(%&nbsp;end)&nbsp;(%&nbsp;start))&nbsp;2)
+                035&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(m&#x2F;expt&nbsp;(-&nbsp;(%&nbsp;end)&nbsp;(%&nbsp;start))&nbsp;2)
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                037&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[:x&nbsp;:y&nbsp;:z])))))
+                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[:x&nbsp;:y&nbsp;:z])))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                038&nbsp;&nbsp;
+                037&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                039&nbsp;&nbsp;(defn&nbsp;centre
+                038&nbsp;&nbsp;(defn&nbsp;centre
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                040&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;vertex&nbsp;that&nbsp;represents&nbsp;the&nbsp;centre&nbsp;of&nbsp;this&nbsp;`edge`.&quot;
+                039&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;vertex&nbsp;that&nbsp;represents&nbsp;the&nbsp;centre&nbsp;of&nbsp;this&nbsp;`edge`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                041&nbsp;&nbsp;&nbsp;&nbsp;[edge]
+                040&nbsp;&nbsp;&nbsp;&nbsp;[edge]
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                042&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[s&nbsp;(ensure3d&nbsp;(:start&nbsp;edge))
+                041&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[s&nbsp;(ensure3d&nbsp;(:start&nbsp;edge))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;e&nbsp;(ensure3d&nbsp;(:end&nbsp;edge))]
+                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;e&nbsp;(ensure3d&nbsp;(:end&nbsp;edge))]
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex
+                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex
                 </span><br/>
 <span class="covered" title="16 out of 16 forms covered">
-                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:x&nbsp;s)&nbsp;(&#x2F;&nbsp;(-&nbsp;(:x&nbsp;e)&nbsp;(:x&nbsp;s))&nbsp;2))
+                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:x&nbsp;s)&nbsp;(&#x2F;&nbsp;(-&nbsp;(:x&nbsp;e)&nbsp;(:x&nbsp;s))&nbsp;2))
                 </span><br/>
 <span class="covered" title="16 out of 16 forms covered">
-                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:y&nbsp;s)&nbsp;(&#x2F;&nbsp;(-&nbsp;(:y&nbsp;e)&nbsp;(:y&nbsp;s))&nbsp;2))
+                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:y&nbsp;s)&nbsp;(&#x2F;&nbsp;(-&nbsp;(:y&nbsp;e)&nbsp;(:y&nbsp;s))&nbsp;2))
                 </span><br/>
 <span class="covered" title="16 out of 16 forms covered">
-                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:z&nbsp;s)&nbsp;(&#x2F;&nbsp;(-&nbsp;(:z&nbsp;e)&nbsp;(:z&nbsp;s))&nbsp;2)))))
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:z&nbsp;s)&nbsp;(&#x2F;&nbsp;(-&nbsp;(:z&nbsp;e)&nbsp;(:z&nbsp;s))&nbsp;2)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                048&nbsp;&nbsp;
+                047&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                049&nbsp;&nbsp;(defn&nbsp;unit-vector
+                048&nbsp;&nbsp;(defn&nbsp;unit-vector
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                050&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;vertex&nbsp;parallel&nbsp;to&nbsp;`e`&nbsp;starting&nbsp;from&nbsp;the&nbsp;coordinate&nbsp;origin.&nbsp;Two
+                049&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;vertex&nbsp;parallel&nbsp;to&nbsp;`e`&nbsp;starting&nbsp;from&nbsp;the&nbsp;coordinate&nbsp;origin.&nbsp;Two
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                051&nbsp;&nbsp;&nbsp;&nbsp;edges&nbsp;which&nbsp;are&nbsp;parallel&nbsp;will&nbsp;have&nbsp;the&nbsp;same&nbsp;unit&nbsp;vector.&quot;
+                050&nbsp;&nbsp;&nbsp;&nbsp;edges&nbsp;which&nbsp;are&nbsp;parallel&nbsp;will&nbsp;have&nbsp;the&nbsp;same&nbsp;unit&nbsp;vector.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                052&nbsp;&nbsp;&nbsp;&nbsp;[e]
+                051&nbsp;&nbsp;&nbsp;&nbsp;[e]
                 </span><br/>
 <span class="covered" title="14 out of 14 forms covered">
-                053&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[e&#x27;&nbsp;{:start&nbsp;(ensure3d&nbsp;(:start&nbsp;e))&nbsp;:end&nbsp;(ensure3d&nbsp;(:end&nbsp;e))}
+                052&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[e&#x27;&nbsp;{:start&nbsp;(ensure3d&nbsp;(:start&nbsp;e))&nbsp;:end&nbsp;(ensure3d&nbsp;(:end&nbsp;e))}
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;l&nbsp;(length&nbsp;e&#x27;)]
+                053&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;l&nbsp;(length&nbsp;e&#x27;)]
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce
+                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;merge
+                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;merge
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{}
+                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{}
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(fn&nbsp;[k]
+                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(fn&nbsp;[k]
                 </span><br/>
 <span class="covered" title="17 out of 17 forms covered">
-                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{k&nbsp;(&#x2F;&nbsp;(-&nbsp;(k&nbsp;(:end&nbsp;e&#x27;))&nbsp;(k&nbsp;(:start&nbsp;e&#x27;)))&nbsp;l)})
+                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{k&nbsp;(&#x2F;&nbsp;(-&nbsp;(k&nbsp;(:end&nbsp;e&#x27;))&nbsp;(k&nbsp;(:start&nbsp;e&#x27;)))&nbsp;l)})
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[:x&nbsp;:y&nbsp;:z]))))
+                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[:x&nbsp;:y&nbsp;:z]))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                062&nbsp;&nbsp;
+                061&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                063&nbsp;&nbsp;(defn&nbsp;parallel?
+                062&nbsp;&nbsp;(defn&nbsp;parallel?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                064&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;all&nbsp;`edges`&nbsp;passed&nbsp;are&nbsp;parallel&nbsp;with&nbsp;one&nbsp;another.&quot;
+                063&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;all&nbsp;`edges`&nbsp;passed&nbsp;are&nbsp;parallel&nbsp;with&nbsp;one&nbsp;another.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                065&nbsp;&nbsp;&nbsp;&nbsp;[&amp;&nbsp;edges]
+                064&nbsp;&nbsp;&nbsp;&nbsp;[&amp;&nbsp;edges]
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                066&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[uvs&nbsp;(map&nbsp;unit-vector&nbsp;edges)]
+                065&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[uvs&nbsp;(map&nbsp;unit-vector&nbsp;edges)]
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?
+                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(vertex=&nbsp;%&nbsp;(first&nbsp;uvs))
+                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(vertex=&nbsp;%&nbsp;(first&nbsp;uvs))
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                069&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(rest&nbsp;uvs))))
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(rest&nbsp;uvs))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                070&nbsp;&nbsp;
+                069&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                071&nbsp;&nbsp;(defn&nbsp;collinear?
+                070&nbsp;&nbsp;(defn&nbsp;collinear?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                072&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;edges&nbsp;`e1`&nbsp;and&nbsp;`e2`&nbsp;are&nbsp;collinear&nbsp;with&nbsp;one&nbsp;another.&quot;
+                071&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;edges&nbsp;`e1`&nbsp;and&nbsp;`e2`&nbsp;are&nbsp;collinear&nbsp;with&nbsp;one&nbsp;another.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                073&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
+                072&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                074&nbsp;&nbsp;&nbsp;&nbsp;(parallel?
+                073&nbsp;&nbsp;&nbsp;&nbsp;(parallel?
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;e1
+                074&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;e1
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;e2
+                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;e2
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(vertex=&nbsp;(:start&nbsp;e1)&nbsp;(:start&nbsp;e2))
+                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(vertex=&nbsp;(:start&nbsp;e1)&nbsp;(:start&nbsp;e2))
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:start&nbsp;(:start&nbsp;e1)&nbsp;:end&nbsp;(:end&nbsp;e2)}
+                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:start&nbsp;(:start&nbsp;e1)&nbsp;:end&nbsp;(:end&nbsp;e2)}
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:start&nbsp;(:start&nbsp;e1)&nbsp;:end&nbsp;(:start&nbsp;e2)})))
+                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:start&nbsp;(:start&nbsp;e1)&nbsp;:end&nbsp;(:start&nbsp;e2)})))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                080&nbsp;&nbsp;
+                079&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                081&nbsp;&nbsp;(defn&nbsp;collinear2d?
+                080&nbsp;&nbsp;(defn&nbsp;collinear2d?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                082&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;the&nbsp;projections&nbsp;of&nbsp;edges&nbsp;`e1`,&nbsp;`e2`&nbsp;onto&nbsp;the&nbsp;x,&nbsp;y&nbsp;plane&nbsp;are
+                081&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;the&nbsp;projections&nbsp;of&nbsp;edges&nbsp;`e1`,&nbsp;`e2`&nbsp;onto&nbsp;the&nbsp;x,&nbsp;y&nbsp;plane&nbsp;are
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                083&nbsp;&nbsp;&nbsp;&nbsp;collinear.&quot;
+                082&nbsp;&nbsp;&nbsp;&nbsp;collinear.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                084&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
+                083&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
                 </span><br/>
 <span class="covered" title="15 out of 15 forms covered">
-                085&nbsp;&nbsp;&nbsp;&nbsp;(collinear?&nbsp;{:start&nbsp;(ensure2d&nbsp;(:start&nbsp;e1))&nbsp;:end&nbsp;(ensure2d&nbsp;(:end&nbsp;e1))}
+                084&nbsp;&nbsp;&nbsp;&nbsp;(collinear?&nbsp;{:start&nbsp;(ensure2d&nbsp;(:start&nbsp;e1))&nbsp;:end&nbsp;(ensure2d&nbsp;(:end&nbsp;e1))}
                 </span><br/>
 <span class="covered" title="13 out of 13 forms covered">
-                086&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:start&nbsp;(ensure2d&nbsp;(:start&nbsp;e2))&nbsp;:end&nbsp;(ensure2d&nbsp;(:end&nbsp;e2))}))
+                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:start&nbsp;(ensure2d&nbsp;(:start&nbsp;e2))&nbsp;:end&nbsp;(ensure2d&nbsp;(:end&nbsp;e2))}))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                087&nbsp;&nbsp;
+                086&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                088&nbsp;&nbsp;(defn&nbsp;minimaxd
+                087&nbsp;&nbsp;(defn&nbsp;minimaxd
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                089&nbsp;&nbsp;&nbsp;&nbsp;&quot;Apply&nbsp;function&nbsp;`f`&nbsp;to&nbsp;`coord`&nbsp;of&nbsp;the&nbsp;vertices&nbsp;at&nbsp;start&nbsp;and&nbsp;end&nbsp;of&nbsp;`edge`
+                088&nbsp;&nbsp;&nbsp;&nbsp;&quot;Apply&nbsp;function&nbsp;`f`&nbsp;to&nbsp;`coord`&nbsp;of&nbsp;the&nbsp;vertices&nbsp;at&nbsp;start&nbsp;and&nbsp;end&nbsp;of&nbsp;`edge`
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                090&nbsp;&nbsp;&nbsp;&nbsp;and&nbsp;return&nbsp;the&nbsp;result.&nbsp;Intended&nbsp;use&nbsp;case&nbsp;is&nbsp;`f`&nbsp;=&nbsp;`min`&nbsp;or&nbsp;`max`,&nbsp;`coord`
+                089&nbsp;&nbsp;&nbsp;&nbsp;and&nbsp;return&nbsp;the&nbsp;result.&nbsp;Intended&nbsp;use&nbsp;case&nbsp;is&nbsp;`f`&nbsp;=&nbsp;`min`&nbsp;or&nbsp;`max`,&nbsp;`coord`
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                091&nbsp;&nbsp;&nbsp;&nbsp;is&nbsp;`:x`,&nbsp;`:y`&nbsp;or&nbsp;`:z`.&nbsp;No&nbsp;checks&nbsp;are&nbsp;made&nbsp;for&nbsp;sane&nbsp;arguments.&quot;
+                090&nbsp;&nbsp;&nbsp;&nbsp;is&nbsp;`:x`,&nbsp;`:y`&nbsp;or&nbsp;`:z`.&nbsp;No&nbsp;checks&nbsp;are&nbsp;made&nbsp;for&nbsp;sane&nbsp;arguments.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                092&nbsp;&nbsp;&nbsp;&nbsp;[edge&nbsp;coord&nbsp;f]
+                091&nbsp;&nbsp;&nbsp;&nbsp;[edge&nbsp;coord&nbsp;f]
                 </span><br/>
 <span class="covered" title="15 out of 15 forms covered">
-                093&nbsp;&nbsp;&nbsp;&nbsp;(apply&nbsp;f&nbsp;(list&nbsp;(coord&nbsp;(:start&nbsp;edge))&nbsp;(coord&nbsp;(:end&nbsp;edge)))))
+                092&nbsp;&nbsp;&nbsp;&nbsp;(apply&nbsp;f&nbsp;(list&nbsp;(coord&nbsp;(:start&nbsp;edge))&nbsp;(coord&nbsp;(:end&nbsp;edge)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                094&nbsp;&nbsp;
+                093&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                095&nbsp;&nbsp;(defn&nbsp;on?
+                094&nbsp;&nbsp;(defn&nbsp;on?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                096&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;the&nbsp;vertex&nbsp;`v`&nbsp;is&nbsp;on&nbsp;the&nbsp;edge&nbsp;`e`.&quot;
+                095&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;the&nbsp;vertex&nbsp;`v`&nbsp;is&nbsp;on&nbsp;the&nbsp;edge&nbsp;`e`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                097&nbsp;&nbsp;&nbsp;&nbsp;[e&nbsp;v]
+                096&nbsp;&nbsp;&nbsp;&nbsp;[e&nbsp;v]
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                098&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[p&nbsp;(ensure3d&nbsp;(:start&nbsp;e))
+                097&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[p&nbsp;(ensure3d&nbsp;(:start&nbsp;e))
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                099&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;q&nbsp;(ensure3d&nbsp;v)
+                098&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;q&nbsp;(ensure3d&nbsp;v)
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;r&nbsp;(ensure3d&nbsp;(:end&nbsp;e))]
+                099&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;r&nbsp;(ensure3d&nbsp;(:end&nbsp;e))]
                 </span><br/>
 <span class="partial" title="20 out of 25 forms covered">
-                101&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(collinear?&nbsp;(edge&nbsp;p&nbsp;q)&nbsp;(edge&nbsp;q&nbsp;r))
+                101&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(collinear?&nbsp;(edge&nbsp;p&nbsp;q)&nbsp;(edge&nbsp;q&nbsp;r))
                 </span><br/>
 <span class="covered" title="13 out of 13 forms covered">
-                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;=&nbsp;(:x&nbsp;q)&nbsp;(max&nbsp;(:x&nbsp;p)&nbsp;(:x&nbsp;r)))
+                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;=&nbsp;(:x&nbsp;q)&nbsp;(max&nbsp;(:x&nbsp;p)&nbsp;(:x&nbsp;r)))
                 </span><br/>
 <span class="covered" title="13 out of 13 forms covered">
-                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;=&nbsp;(:x&nbsp;q)&nbsp;(min&nbsp;(:x&nbsp;p)&nbsp;(:x&nbsp;r)))
+                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;=&nbsp;(:x&nbsp;q)&nbsp;(min&nbsp;(:x&nbsp;p)&nbsp;(:x&nbsp;r)))
                 </span><br/>
 <span class="covered" title="13 out of 13 forms covered">
-                105&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;=&nbsp;(:y&nbsp;q)&nbsp;(max&nbsp;(:y&nbsp;p)&nbsp;(:y&nbsp;r)))
+                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;=&nbsp;(:y&nbsp;q)&nbsp;(max&nbsp;(:y&nbsp;p)&nbsp;(:y&nbsp;r)))
                 </span><br/>
 <span class="covered" title="13 out of 13 forms covered">
-                106&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;=&nbsp;(:y&nbsp;q)&nbsp;(min&nbsp;(:y&nbsp;p)&nbsp;(:y&nbsp;r)))
+                105&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;=&nbsp;(:y&nbsp;q)&nbsp;(min&nbsp;(:y&nbsp;p)&nbsp;(:y&nbsp;r)))
                 </span><br/>
 <span class="covered" title="13 out of 13 forms covered">
-                107&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;=&nbsp;(:z&nbsp;q)&nbsp;(max&nbsp;(:z&nbsp;p)&nbsp;(:z&nbsp;r)))
+                106&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;=&nbsp;(:z&nbsp;q)&nbsp;(max&nbsp;(:z&nbsp;p)&nbsp;(:z&nbsp;r)))
                 </span><br/>
 <span class="covered" title="12 out of 12 forms covered">
-                108&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;=&nbsp;(:z&nbsp;q)&nbsp;(min&nbsp;(:z&nbsp;p)&nbsp;(:z&nbsp;r))))))
+                107&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;=&nbsp;(:z&nbsp;q)&nbsp;(min&nbsp;(:z&nbsp;p)&nbsp;(:z&nbsp;r))))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                109&nbsp;&nbsp;
+                108&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                110&nbsp;&nbsp;(defn&nbsp;on2d?
+                109&nbsp;&nbsp;(defn&nbsp;on2d?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                111&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;vertex&nbsp;`v`&nbsp;is&nbsp;on&nbsp;edge&nbsp;`e`&nbsp;when&nbsp;projected&nbsp;onto&nbsp;the&nbsp;x,&nbsp;y&nbsp;plane.&quot;
+                110&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;vertex&nbsp;`v`&nbsp;is&nbsp;on&nbsp;edge&nbsp;`e`&nbsp;when&nbsp;projected&nbsp;onto&nbsp;the&nbsp;x,&nbsp;y&nbsp;plane.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                112&nbsp;&nbsp;&nbsp;&nbsp;[e&nbsp;v]
+                111&nbsp;&nbsp;&nbsp;&nbsp;[e&nbsp;v]
                 </span><br/>
 <span class="covered" title="15 out of 15 forms covered">
-                113&nbsp;&nbsp;&nbsp;&nbsp;(on?&nbsp;(edge&nbsp;(ensure2d&nbsp;(:start&nbsp;e))&nbsp;(ensure2d&nbsp;(:end&nbsp;e)))&nbsp;v))
+                112&nbsp;&nbsp;&nbsp;&nbsp;(on?&nbsp;(edge&nbsp;(ensure2d&nbsp;(:start&nbsp;e))&nbsp;(ensure2d&nbsp;(:end&nbsp;e)))&nbsp;v))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                114&nbsp;&nbsp;
+                113&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                115&nbsp;&nbsp;(defn&nbsp;overlaps2d?
+                114&nbsp;&nbsp;(defn&nbsp;overlaps2d?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                116&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;the&nbsp;recangle&nbsp;in&nbsp;the&nbsp;x,y&nbsp;plane&nbsp;bisected&nbsp;by&nbsp;edge&nbsp;`e1`&nbsp;overlaps&nbsp;that
+                115&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;the&nbsp;recangle&nbsp;in&nbsp;the&nbsp;x,y&nbsp;plane&nbsp;bisected&nbsp;by&nbsp;edge&nbsp;`e1`&nbsp;overlaps&nbsp;that
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                117&nbsp;&nbsp;&nbsp;&nbsp;bisected&nbsp;by&nbsp;edge&nbsp;`e2`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;if&nbsp;either&nbsp;`e1`&nbsp;or&nbsp;`e2`&nbsp;is&nbsp;not&nbsp;an&nbsp;edge.&quot;
+                116&nbsp;&nbsp;&nbsp;&nbsp;bisected&nbsp;by&nbsp;edge&nbsp;`e2`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;if&nbsp;either&nbsp;`e1`&nbsp;or&nbsp;`e2`&nbsp;is&nbsp;not&nbsp;an&nbsp;edge.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                118&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
+                117&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
                 </span><br/>
 <span class="partial" title="11 out of 12 forms covered">
-                119&nbsp;&nbsp;&nbsp;&nbsp;(when&nbsp;(and&nbsp;(edge?&nbsp;e1)&nbsp;(edge?&nbsp;e2))
+                118&nbsp;&nbsp;&nbsp;&nbsp;(when&nbsp;(and&nbsp;(edge?&nbsp;e1)&nbsp;(edge?&nbsp;e2))
                 </span><br/>
 <span class="partial" title="11 out of 13 forms covered">
-                120&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                119&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="covered" title="12 out of 12 forms covered">
-                121&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(minimaxd&nbsp;e1&nbsp;:x&nbsp;max)&nbsp;(minimaxd&nbsp;e2&nbsp;:x&nbsp;min))
+                120&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(minimaxd&nbsp;e1&nbsp;:x&nbsp;max)&nbsp;(minimaxd&nbsp;e2&nbsp;:x&nbsp;min))
                 </span><br/>
 <span class="covered" title="12 out of 12 forms covered">
-                122&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;&nbsp;(minimaxd&nbsp;e1&nbsp;:x&nbsp;min)&nbsp;(minimaxd&nbsp;e2&nbsp;:x&nbsp;max))
+                121&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;&nbsp;(minimaxd&nbsp;e1&nbsp;:x&nbsp;min)&nbsp;(minimaxd&nbsp;e2&nbsp;:x&nbsp;max))
                 </span><br/>
 <span class="covered" title="12 out of 12 forms covered">
-                123&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(minimaxd&nbsp;e1&nbsp;:y&nbsp;max)&nbsp;(minimaxd&nbsp;e2&nbsp;:y&nbsp;min))
+                122&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(minimaxd&nbsp;e1&nbsp;:y&nbsp;max)&nbsp;(minimaxd&nbsp;e2&nbsp;:y&nbsp;min))
                 </span><br/>
 <span class="covered" title="11 out of 11 forms covered">
-                124&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;&nbsp;(minimaxd&nbsp;e1&nbsp;:y&nbsp;min)&nbsp;(minimaxd&nbsp;e2&nbsp;:y&nbsp;max)))))
+                123&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;&nbsp;(minimaxd&nbsp;e1&nbsp;:y&nbsp;min)&nbsp;(minimaxd&nbsp;e2&nbsp;:y&nbsp;max)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                125&nbsp;&nbsp;
+                124&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                125&nbsp;&nbsp;(defn&nbsp;intersection2d
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                126&nbsp;&nbsp;;;&nbsp;Don&#x27;t&nbsp;think&nbsp;I&nbsp;need&nbsp;this.
+                126&nbsp;&nbsp;&nbsp;&nbsp;&quot;The&nbsp;probability&nbsp;of&nbsp;two&nbsp;lines&nbsp;intersecting&nbsp;in&nbsp;3d&nbsp;space&nbsp;is&nbsp;low,&nbsp;and&nbsp;actually
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                127&nbsp;&nbsp;;;&nbsp;(defn&nbsp;orientation
+                127&nbsp;&nbsp;&nbsp;&nbsp;that&nbsp;is&nbsp;mostly&nbsp;not&nbsp;something&nbsp;we&#x27;re&nbsp;interested&nbsp;in.&nbsp;We&#x27;re&nbsp;interested&nbsp;in
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                128&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;&quot;Determine&nbsp;whether&nbsp;the&nbsp;ordered&nbsp;sequence&nbsp;of&nbsp;vertices&nbsp;`p`,&nbsp;`q`&nbsp;and&nbsp;`r`&nbsp;run
+                128&nbsp;&nbsp;&nbsp;&nbsp;intersection&nbsp;in&nbsp;the&nbsp;`x,y`&nbsp;plane.&nbsp;This&nbsp;function&nbsp;returns&nbsp;a&nbsp;vertex&nbsp;representing
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                129&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;clockwise,&nbsp;collinear&nbsp;or&nbsp;anticlockwise&nbsp;in&nbsp;the&nbsp;x,y&nbsp;plane.&quot;
+                129&nbsp;&nbsp;&nbsp;&nbsp;a&nbsp;point&nbsp;vertically&nbsp;over&nbsp;the&nbsp;intersection&nbsp;of&nbsp;edges&nbsp;`e1`,&nbsp;`e2`&nbsp;in&nbsp;the&nbsp;`x,y`
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                130&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;[p&nbsp;q&nbsp;r]
+                130&nbsp;&nbsp;&nbsp;&nbsp;plane,&nbsp;whose&nbsp;`z`&nbsp;coordinate&nbsp;is
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                131&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                131&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;(let&nbsp;[v&nbsp;(-&nbsp;(*&nbsp;(-&nbsp;(:y&nbsp;q)&nbsp;(:y&nbsp;p))&nbsp;(-&nbsp;(:x&nbsp;r)&nbsp;(:x&nbsp;q)))
+                132&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;0&nbsp;if&nbsp;both&nbsp;edges&nbsp;are&nbsp;2d&nbsp;(i.e.&nbsp;have&nbsp;missing&nbsp;or&nbsp;zero&nbsp;`z`&nbsp;coordinates);
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                132&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(-&nbsp;(:x&nbsp;q)&nbsp;(:x&nbsp;p))&nbsp;(-&nbsp;(:y&nbsp;r)&nbsp;(:y&nbsp;q))))]
+                133&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;if&nbsp;one&nbsp;edge&nbsp;is&nbsp;2d,&nbsp;then&nbsp;the&nbsp;point&nbsp;on&nbsp;the&nbsp;other&nbsp;edge&nbsp;over&nbsp;the&nbsp;intersection;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                133&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
+                134&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;otherwise,&nbsp;the&nbsp;average&nbsp;of&nbsp;the&nbsp;z&nbsp;coordinates&nbsp;of&nbsp;the&nbsp;points&nbsp;on&nbsp;the&nbsp;two
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                134&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(zero?&nbsp;v)&nbsp;:collinear
+                135&nbsp;&nbsp;&nbsp;&nbsp;edges&nbsp;over&nbsp;the&nbsp;intersection.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                136&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                135&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(pos?&nbsp;v)&nbsp;:clockwise
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                136&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                137&nbsp;&nbsp;;;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:anticlockwise)))
+                137&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;no&nbsp;such&nbsp;intersection&nbsp;exists,&nbsp;`nil`&nbsp;is&nbsp;returned.
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
                 138&nbsp;&nbsp;
                 </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                139&nbsp;&nbsp;(defn&nbsp;intersection2d
+<span class="not-tracked" title="0 out of 0 forms covered">
+                139&nbsp;&nbsp;&nbsp;&nbsp;It&nbsp;is&nbsp;an&nbsp;error,&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown,&nbsp;if&nbsp;either&nbsp;`e1`&nbsp;or&nbsp;`e2`&nbsp;is
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                140&nbsp;&nbsp;&nbsp;&nbsp;&quot;The&nbsp;probability&nbsp;of&nbsp;two&nbsp;lines&nbsp;intersecting&nbsp;in&nbsp;3d&nbsp;space&nbsp;is&nbsp;low,&nbsp;and&nbsp;actually
+                140&nbsp;&nbsp;&nbsp;&nbsp;not&nbsp;an&nbsp;edge.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                141&nbsp;&nbsp;&nbsp;&nbsp;that&nbsp;is&nbsp;mostly&nbsp;not&nbsp;something&nbsp;we&#x27;re&nbsp;interested&nbsp;in.&nbsp;We&#x27;re&nbsp;interested&nbsp;in
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                142&nbsp;&nbsp;&nbsp;&nbsp;intersection&nbsp;in&nbsp;the&nbsp;`x,y`&nbsp;plane.&nbsp;This&nbsp;function&nbsp;returns&nbsp;a&nbsp;vertex&nbsp;representing
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                143&nbsp;&nbsp;&nbsp;&nbsp;a&nbsp;point&nbsp;vertically&nbsp;over&nbsp;the&nbsp;intersection&nbsp;of&nbsp;edges&nbsp;`e1`,&nbsp;`e2`&nbsp;in&nbsp;the&nbsp;`x,y`
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                144&nbsp;&nbsp;&nbsp;&nbsp;plane,&nbsp;whose&nbsp;`z`&nbsp;coordinate&nbsp;is
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                145&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                146&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;0&nbsp;if&nbsp;both&nbsp;edges&nbsp;are&nbsp;2d&nbsp;(i.e.&nbsp;have&nbsp;missing&nbsp;or&nbsp;zero&nbsp;`z`&nbsp;coordinates);
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                147&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;if&nbsp;one&nbsp;edge&nbsp;is&nbsp;2d,&nbsp;then&nbsp;the&nbsp;point&nbsp;on&nbsp;the&nbsp;other&nbsp;edge&nbsp;over&nbsp;the&nbsp;intersection;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                148&nbsp;&nbsp;&nbsp;&nbsp;*&nbsp;otherwise,&nbsp;the&nbsp;average&nbsp;of&nbsp;the&nbsp;z&nbsp;coordinates&nbsp;of&nbsp;the&nbsp;points&nbsp;on&nbsp;the&nbsp;two
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                149&nbsp;&nbsp;&nbsp;&nbsp;edges&nbsp;over&nbsp;the&nbsp;intersection.
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                150&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                151&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;no&nbsp;such&nbsp;intersection&nbsp;exists,&nbsp;`nil`&nbsp;is&nbsp;returned.
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                152&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                153&nbsp;&nbsp;&nbsp;&nbsp;It&nbsp;is&nbsp;an&nbsp;error,&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown,&nbsp;if&nbsp;either&nbsp;`e1`&nbsp;or&nbsp;`e2`&nbsp;is
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                154&nbsp;&nbsp;&nbsp;&nbsp;not&nbsp;an&nbsp;edge.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                155&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
+                141&nbsp;&nbsp;&nbsp;&nbsp;[e1&nbsp;e2]
                 </span><br/>
 <span class="covered" title="11 out of 11 forms covered">
-                156&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(and&nbsp;(edge?&nbsp;e1)&nbsp;(edge?&nbsp;e2))
+                142&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(and&nbsp;(edge?&nbsp;e1)&nbsp;(edge?&nbsp;e2))
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                157&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when
+                143&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                158&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(overlaps2d?&nbsp;e1&nbsp;e2)&nbsp;;;&nbsp;relatively&nbsp;cheap&nbsp;check
+                144&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(overlaps2d?&nbsp;e1&nbsp;e2)&nbsp;;;&nbsp;relatively&nbsp;cheap&nbsp;check
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                159&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
+                145&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                160&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(collinear2d?&nbsp;e1&nbsp;e2)
+                146&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(collinear2d?&nbsp;e1&nbsp;e2)
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                161&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;any&nbsp;point&nbsp;within&nbsp;the&nbsp;overlap&nbsp;will&nbsp;do,&nbsp;but&nbsp;we&#x27;ll&nbsp;pick&nbsp;the&nbsp;end&nbsp;of&nbsp;e1
+                147&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;any&nbsp;point&nbsp;within&nbsp;the&nbsp;overlap&nbsp;will&nbsp;do,&nbsp;but&nbsp;we&#x27;ll&nbsp;pick&nbsp;the&nbsp;end&nbsp;of&nbsp;e1
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                162&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;which&nbsp;is&nbsp;on&nbsp;e2
+                148&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;which&nbsp;is&nbsp;on&nbsp;e2
                 </span><br/>
 <span class="partial" title="10 out of 13 forms covered">
-                163&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(on2d?&nbsp;e2&nbsp;(:start&nbsp;e1))&nbsp;(:start&nbsp;e1)&nbsp;(:end&nbsp;e1))
+                149&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(on2d?&nbsp;e2&nbsp;(:start&nbsp;e1))&nbsp;(:start&nbsp;e1)&nbsp;(:end&nbsp;e1))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                164&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;blatantly&nbsp;stolen&nbsp;from
+                150&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;blatantly&nbsp;stolen&nbsp;from
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                165&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;https:&#x2F;&#x2F;gist.github.com&#x2F;cassiel&#x2F;3e725b49670356a9b936
+                151&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;https:&#x2F;&#x2F;gist.github.com&#x2F;cassiel&#x2F;3e725b49670356a9b936
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                166&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[x1&nbsp;(:x&nbsp;(:start&nbsp;e1))
+                152&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[x1&nbsp;(:x&nbsp;(:start&nbsp;e1))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                167&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x2&nbsp;(:x&nbsp;(:end&nbsp;e1))
+                153&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x2&nbsp;(:x&nbsp;(:end&nbsp;e1))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                168&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x3&nbsp;(:x&nbsp;(:start&nbsp;e2))
+                154&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x3&nbsp;(:x&nbsp;(:start&nbsp;e2))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                169&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x4&nbsp;(:x&nbsp;(:end&nbsp;e2))
+                155&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x4&nbsp;(:x&nbsp;(:end&nbsp;e2))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                170&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y1&nbsp;(:y&nbsp;(:start&nbsp;e1))
+                156&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y1&nbsp;(:y&nbsp;(:start&nbsp;e1))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                171&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y2&nbsp;(:y&nbsp;(:end&nbsp;e1))
+                157&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y2&nbsp;(:y&nbsp;(:end&nbsp;e1))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                172&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y3&nbsp;(:y&nbsp;(:start&nbsp;e2))
+                158&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y3&nbsp;(:y&nbsp;(:start&nbsp;e2))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                173&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y4&nbsp;(:y&nbsp;(:end&nbsp;e2))
+                159&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y4&nbsp;(:y&nbsp;(:end&nbsp;e2))
                 </span><br/>
 <span class="covered" title="12 out of 12 forms covered">
-                174&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;denom&nbsp;(-&nbsp;(*&nbsp;(-&nbsp;x1&nbsp;x2)&nbsp;(-&nbsp;y3&nbsp;y4))
+                160&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;denom&nbsp;(-&nbsp;(*&nbsp;(-&nbsp;x1&nbsp;x2)&nbsp;(-&nbsp;y3&nbsp;y4))
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                175&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(-&nbsp;y1&nbsp;y2)&nbsp;(-&nbsp;x3&nbsp;x4)))
+                161&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(-&nbsp;y1&nbsp;y2)&nbsp;(-&nbsp;x3&nbsp;x4)))
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                176&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x1y2-y1x2&nbsp;(-&nbsp;(*&nbsp;x1&nbsp;y2)&nbsp;(*&nbsp;y1&nbsp;x2))
+                162&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x1y2-y1x2&nbsp;(-&nbsp;(*&nbsp;x1&nbsp;y2)&nbsp;(*&nbsp;y1&nbsp;x2))
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                177&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x3y4-y3x4&nbsp;(-&nbsp;(*&nbsp;x3&nbsp;y4)&nbsp;(*&nbsp;y3&nbsp;x4))
+                163&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x3y4-y3x4&nbsp;(-&nbsp;(*&nbsp;x3&nbsp;y4)&nbsp;(*&nbsp;y3&nbsp;x4))
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                178&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;px-num&nbsp;(-&nbsp;(*&nbsp;x1y2-y1x2&nbsp;(-&nbsp;x3&nbsp;x4))
+                164&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;px-num&nbsp;(-&nbsp;(*&nbsp;x1y2-y1x2&nbsp;(-&nbsp;x3&nbsp;x4))
                 </span><br/>
 <span class="covered" title="7 out of 7 forms covered">
-                179&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(-&nbsp;x1&nbsp;x2)&nbsp;x3y4-y3x4))
+                165&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(-&nbsp;x1&nbsp;x2)&nbsp;x3y4-y3x4))
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                180&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;py-num&nbsp;(-&nbsp;(*&nbsp;x1y2-y1x2&nbsp;(-&nbsp;y3&nbsp;y4))
+                166&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;py-num&nbsp;(-&nbsp;(*&nbsp;x1y2-y1x2&nbsp;(-&nbsp;y3&nbsp;y4))
                 </span><br/>
 <span class="covered" title="7 out of 7 forms covered">
-                181&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(-&nbsp;y1&nbsp;y2)&nbsp;x3y4-y3x4))
+                167&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(-&nbsp;y1&nbsp;y2)&nbsp;x3y4-y3x4))
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                182&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;result&nbsp;(when-not&nbsp;(zero?&nbsp;denom)
+                168&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;result&nbsp;(when-not&nbsp;(zero?&nbsp;denom)
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                183&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex&nbsp;(&#x2F;&nbsp;px-num&nbsp;denom)&nbsp;(&#x2F;&nbsp;py-num&nbsp;denom)))]
+                169&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex&nbsp;(&#x2F;&nbsp;px-num&nbsp;denom)&nbsp;(&#x2F;&nbsp;py-num&nbsp;denom)))]
                 </span><br/>
 <span class="partial" title="19 out of 20 forms covered">
-                184&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when&nbsp;(and&nbsp;result&nbsp;(on2d?&nbsp;e1&nbsp;result)&nbsp;(on2d?&nbsp;e2&nbsp;result))&nbsp;result))))
+                170&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when&nbsp;(and&nbsp;result&nbsp;(on2d?&nbsp;e1&nbsp;result)&nbsp;(on2d?&nbsp;e2&nbsp;result))&nbsp;result))))
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                185&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                171&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                186&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
+                172&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                187&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;Both&nbsp;`e1`&nbsp;and&nbsp;`e2`&nbsp;must&nbsp;be&nbsp;edges.&quot;
+                173&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;Both&nbsp;`e1`&nbsp;and&nbsp;`e2`&nbsp;must&nbsp;be&nbsp;edges.&quot;
                 </span><br/>
 <span class="covered" title="16 out of 16 forms covered">
-                188&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map&nbsp;#(or&nbsp;(:kind&nbsp;%)&nbsp;(type&nbsp;%))&nbsp;[e1&nbsp;e2]))))))
+                174&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map&nbsp;#(or&nbsp;(:kind&nbsp;%)&nbsp;(type&nbsp;%))&nbsp;[e1&nbsp;e2]))))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                189&nbsp;&nbsp;
+                175&nbsp;&nbsp;
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/id.clj.html b/docs/cloverage/walkmap/id.clj.html
new file mode 100644
index 0000000..1fc9abe
--- /dev/null
+++ b/docs/cloverage/walkmap/id.clj.html
@@ -0,0 +1,32 @@
+<html>
+ <head>
+   <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+  <link rel="stylesheet" href="../coverage.css"/>  <title> walkmap/id.clj </title>
+ </head>
+ <body>
+<span class="covered" title="1 out of 1 forms covered">
+                001&nbsp;&nbsp;(ns&nbsp;walkmap.id
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                002&nbsp;&nbsp;&nbsp;&nbsp;&quot;The&nbsp;namespace&nbsp;within&nbsp;which&nbsp;the&nbsp;privileged&nbsp;keyword&nbsp;`:walkmap.id&#x2F;id`&nbsp;is&nbsp;defined.&quot;)
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                003&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                004&nbsp;&nbsp;(def&nbsp;^:const&nbsp;id
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                005&nbsp;&nbsp;&nbsp;&nbsp;&quot;The&nbsp;magic&nbsp;id&nbsp;key&nbsp;walkmap&nbsp;uses,&nbsp;to&nbsp;distinguish&nbsp;it&nbsp;from&nbsp;all&nbsp;other&nbsp;uses&nbsp;of
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                006&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;unprotected&nbsp;keyword.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                007&nbsp;&nbsp;&nbsp;&nbsp;::id)
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                008&nbsp;&nbsp;
+                </span><br/>
+ </body>
+</html>
diff --git a/docs/cloverage/walkmap/ocean.clj.html b/docs/cloverage/walkmap/ocean.clj.html
index eb20c01..f729ad3 100644
--- a/docs/cloverage/walkmap/ocean.clj.html
+++ b/docs/cloverage/walkmap/ocean.clj.html
@@ -49,13 +49,13 @@
 <span class="not-tracked" title="0 out of 0 forms covered">
                 015&nbsp;&nbsp;&nbsp;&nbsp;[facet]
                 </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
+<span class="covered" title="3 out of 3 forms covered">
                 016&nbsp;&nbsp;&nbsp;&nbsp;(every?
                 </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
+<span class="covered" title="4 out of 4 forms covered">
                 017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(=&nbsp;%&nbsp;*sea-level*)
                 </span><br/>
-<span class="not-covered" title="0 out of 6 forms covered">
+<span class="covered" title="6 out of 6 forms covered">
                 018&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map&nbsp;:z&nbsp;(:vertices&nbsp;facet))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
diff --git a/docs/cloverage/walkmap/path.clj.html b/docs/cloverage/walkmap/path.clj.html
index 025d1dc..ea999df 100644
--- a/docs/cloverage/walkmap/path.clj.html
+++ b/docs/cloverage/walkmap/path.clj.html
@@ -17,226 +17,244 @@
                 004&nbsp;&nbsp;&nbsp;&nbsp;feature,&nbsp;where&nbsp;such&nbsp;features&nbsp;specifically&nbsp;include&nbsp;watercourses.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                005&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[walkmap.edge&nbsp;:as&nbsp;e]
+                005&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.string&nbsp;:as&nbsp;s]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:refer&nbsp;[polygon?]]
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.edge&nbsp;:as&nbsp;e]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[vertex?]]))
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:refer&nbsp;[polygon?]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:refer&nbsp;[kind-type]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                009&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[vertex?]]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                008&nbsp;&nbsp;
+                010&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                009&nbsp;&nbsp;(defn&nbsp;path?
+                011&nbsp;&nbsp;(defn&nbsp;path?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                010&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;path.&nbsp;A&nbsp;path&nbsp;shall&nbsp;be&nbsp;a&nbsp;map
+                012&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;path.&nbsp;A&nbsp;path&nbsp;shall&nbsp;be&nbsp;a&nbsp;map
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;having&nbsp;the&nbsp;key&nbsp;`:vertices`,&nbsp;whose&nbsp;value&nbsp;shall&nbsp;be&nbsp;a&nbsp;sequence&nbsp;of&nbsp;vertices&nbsp;as
+                013&nbsp;&nbsp;&nbsp;&nbsp;having&nbsp;the&nbsp;key&nbsp;`:vertices`,&nbsp;whose&nbsp;value&nbsp;shall&nbsp;be&nbsp;a&nbsp;sequence&nbsp;of&nbsp;vertices&nbsp;as
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;defined&nbsp;in&nbsp;`walkmap.vertex`.&quot;
+                014&nbsp;&nbsp;&nbsp;&nbsp;defined&nbsp;in&nbsp;`walkmap.vertex`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                013&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                015&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                014&nbsp;&nbsp;&nbsp;&nbsp;(let
+                016&nbsp;&nbsp;&nbsp;&nbsp;(let
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                015&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[v&nbsp;(:vertices&nbsp;o)]
+                017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[v&nbsp;(:vertices&nbsp;o)]
                 </span><br/>
 <span class="not-covered" title="0 out of 22 forms covered">
-                016&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                018&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(seq?&nbsp;v)
+                019&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(seq?&nbsp;v)
                 </span><br/>
 <span class="not-covered" title="0 out of 6 forms covered">
-                018&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(count&nbsp;v)&nbsp;2)
+                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(count&nbsp;v)&nbsp;2)
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                019&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;vertex?&nbsp;v)
+                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;vertex?&nbsp;v)
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:id&nbsp;o)
+                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
                 </span><br/>
 <span class="not-covered" title="0 out of 9 forms covered">
-                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:path)))))
+                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:path)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                022&nbsp;&nbsp;
+                024&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                023&nbsp;&nbsp;(defn&nbsp;path
+                025&nbsp;&nbsp;(defn&nbsp;path
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                024&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;path&nbsp;constructed&nbsp;from&nbsp;these&nbsp;`vertices`.&quot;
+                026&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;path&nbsp;constructed&nbsp;from&nbsp;these&nbsp;`vertices`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                025&nbsp;&nbsp;&nbsp;&nbsp;[&amp;&nbsp;vertices]
+                027&nbsp;&nbsp;&nbsp;&nbsp;[&amp;&nbsp;vertices]
                 </span><br/>
-<span class="not-covered" title="0 out of 1 forms covered">
-                026&nbsp;&nbsp;&nbsp;&nbsp;(if
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                027&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;vertex?&nbsp;vertices)
-                </span><br/>
-<span class="not-covered" title="0 out of 11 forms covered">
-                028&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:vertices&nbsp;vertices&nbsp;:id&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;path&quot;))&nbsp;:kind&nbsp;:path}
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Each&nbsp;item&nbsp;on&nbsp;path&nbsp;must&nbsp;be&nbsp;a&nbsp;vertex.&quot;))))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                030&nbsp;&nbsp;
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                031&nbsp;&nbsp;(defn&nbsp;polygon-&gt;path
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                032&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;a&nbsp;polygon,&nbsp;return&nbsp;an&nbsp;equivalent&nbsp;path.&nbsp;What&#x27;s&nbsp;different&nbsp;about
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                033&nbsp;&nbsp;&nbsp;&nbsp;a&nbsp;path&nbsp;is&nbsp;that&nbsp;in&nbsp;polygons&nbsp;there&nbsp;is&nbsp;an&nbsp;implicit&nbsp;edge&nbsp;between&nbsp;the&nbsp;first
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                034&nbsp;&nbsp;&nbsp;&nbsp;vertex&nbsp;and&nbsp;the&nbsp;last.&nbsp;In&nbsp;paths,&nbsp;there&nbsp;isn&#x27;t,&nbsp;so&nbsp;we&nbsp;need&nbsp;to&nbsp;add&nbsp;that
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                035&nbsp;&nbsp;&nbsp;&nbsp;edge&nbsp;explicitly.
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                036&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                037&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;polygon,&nbsp;will&nbsp;throw&nbsp;an&nbsp;exception.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                038&nbsp;&nbsp;&nbsp;&nbsp;[o]
-                </span><br/>
-<span class="not-covered" title="0 out of 1 forms covered">
-                039&nbsp;&nbsp;&nbsp;&nbsp;(if
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                040&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(polygon?&nbsp;o)
-                </span><br/>
-<span class="not-covered" title="0 out of 21 forms covered">
-                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;(dissoc&nbsp;o&nbsp;:vertices)&nbsp;:kind&nbsp;:path&nbsp;:vertices&nbsp;(concat&nbsp;(:vertices&nbsp;o)&nbsp;(list&nbsp;(first&nbsp;(:vertices&nbsp;o)))))
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Not&nbsp;a&nbsp;polygon!&quot;))))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                043&nbsp;&nbsp;
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                044&nbsp;&nbsp;(defn&nbsp;path-&gt;edges
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                045&nbsp;&nbsp;&nbsp;&nbsp;&quot;if&nbsp;`o`&nbsp;is&nbsp;a&nbsp;path,&nbsp;a&nbsp;polygon,&nbsp;or&nbsp;a&nbsp;sequence&nbsp;of&nbsp;vertices,&nbsp;return&nbsp;a&nbsp;sequence&nbsp;of
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                046&nbsp;&nbsp;&nbsp;&nbsp;edges&nbsp;representing&nbsp;that&nbsp;path,&nbsp;polygon&nbsp;or&nbsp;sequence.
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                047&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                048&nbsp;&nbsp;&nbsp;&nbsp;Throws&nbsp;`IllegalArgumentException`&nbsp;if&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;path,&nbsp;a&nbsp;polygon,&nbsp;or
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                049&nbsp;&nbsp;&nbsp;&nbsp;sequence&nbsp;of&nbsp;vertices.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                050&nbsp;&nbsp;&nbsp;&nbsp;[o]
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                051&nbsp;&nbsp;&nbsp;&nbsp;(cond
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                052&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(seq?&nbsp;o)
+<span class="partial" title="6 out of 7 forms covered">
+                028&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(every?&nbsp;vertex?&nbsp;vertices)
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                053&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when
+                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="not-covered" title="0 out of 5 forms covered">
-                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+<span class="not-covered" title="0 out of 3 forms covered">
+                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
                 </span><br/>
-<span class="not-covered" title="0 out of 5 forms covered">
-                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(first&nbsp;o))
+<span class="not-tracked" title="0 out of 0 forms covered">
+                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;Each&nbsp;item&nbsp;on&nbsp;path&nbsp;must&nbsp;be&nbsp;a&nbsp;vertex:&nbsp;&quot;
+                </span><br/>
+<span class="not-covered" title="0 out of 10 forms covered">
+                032&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;kind-type&nbsp;(remove&nbsp;vertex?&nbsp;vertices)))))))
+                </span><br/>
+<span class="covered" title="11 out of 11 forms covered">
+                033&nbsp;&nbsp;&nbsp;&nbsp;{:vertices&nbsp;vertices&nbsp;:walkmap.id&#x2F;id&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;path&quot;))&nbsp;:kind&nbsp;:path})
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                034&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                035&nbsp;&nbsp;(defn&nbsp;polygon-&gt;path
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                036&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;a&nbsp;polygon,&nbsp;return&nbsp;an&nbsp;equivalent&nbsp;path.&nbsp;What&#x27;s&nbsp;different&nbsp;about
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                037&nbsp;&nbsp;&nbsp;&nbsp;a&nbsp;path&nbsp;is&nbsp;that&nbsp;in&nbsp;polygons&nbsp;there&nbsp;is&nbsp;an&nbsp;implicit&nbsp;edge&nbsp;between&nbsp;the&nbsp;first
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                038&nbsp;&nbsp;&nbsp;&nbsp;vertex&nbsp;and&nbsp;the&nbsp;last.&nbsp;In&nbsp;paths,&nbsp;there&nbsp;isn&#x27;t,&nbsp;so&nbsp;we&nbsp;need&nbsp;to&nbsp;add&nbsp;that
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                039&nbsp;&nbsp;&nbsp;&nbsp;edge&nbsp;explicitly.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                040&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                041&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;polygon,&nbsp;will&nbsp;throw&nbsp;an&nbsp;exception.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                042&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
 <span class="not-covered" title="0 out of 6 forms covered">
-                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(first&nbsp;(rest&nbsp;o))))
-                </span><br/>
-<span class="not-covered" title="0 out of 2 forms covered">
-                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;TODO:&nbsp;think&nbsp;about:&nbsp;when&nbsp;constructing&nbsp;an&nbsp;edge&nbsp;from&nbsp;a&nbsp;path,&nbsp;should&nbsp;the
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;constructed&nbsp;edge&nbsp;be&nbsp;tagged&nbsp;with&nbsp;the&nbsp;tags&nbsp;of&nbsp;the&nbsp;path?
+                043&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(polygon?&nbsp;o)
                 </span><br/>
 <span class="not-covered" title="0 out of 8 forms covered">
-                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e&#x2F;edge&nbsp;(first&nbsp;o)&nbsp;(rest&nbsp;o))
-                </span><br/>
-<span class="not-covered" title="0 out of 5 forms covered">
-                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path-&gt;edges&nbsp;(rest&nbsp;o))))
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path?&nbsp;o)
-                </span><br/>
-<span class="not-covered" title="0 out of 5 forms covered">
-                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path-&gt;edges&nbsp;(:vertices&nbsp;o))
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;Not&nbsp;a&nbsp;path&nbsp;or&nbsp;sequence&nbsp;of&nbsp;vertices!&quot;))))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                067&nbsp;&nbsp;
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                068&nbsp;&nbsp;(defn&nbsp;length
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                069&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;length&nbsp;of&nbsp;this&nbsp;path,&nbsp;in&nbsp;metres.&nbsp;**Note&nbsp;that**
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                070&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;This&nbsp;is&nbsp;not&nbsp;the&nbsp;same&nbsp;as&nbsp;the&nbsp;distance&nbsp;from&nbsp;the&nbsp;start&nbsp;to&nbsp;the&nbsp;end&nbsp;of&nbsp;the
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                071&nbsp;&nbsp;&nbsp;&nbsp;path,&nbsp;which,&nbsp;except&nbsp;for&nbsp;absolutely&nbsp;straight&nbsp;paths,&nbsp;will&nbsp;be&nbsp;shorter;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                072&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;It&nbsp;is&nbsp;not&nbsp;even&nbsp;quite&nbsp;the&nbsp;same&nbsp;as&nbsp;the&nbsp;length&nbsp;of&nbsp;the&nbsp;path&nbsp;*as&nbsp;rendered*,
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                073&nbsp;&nbsp;&nbsp;&nbsp;since&nbsp;paths&nbsp;will&nbsp;generally&nbsp;be&nbsp;rendered&nbsp;as&nbsp;spline&nbsp;curves.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                074&nbsp;&nbsp;&nbsp;&nbsp;[path]
-                </span><br/>
-<span class="not-covered" title="0 out of 1 forms covered">
-                075&nbsp;&nbsp;&nbsp;&nbsp;(if
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path?&nbsp;path)
+                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;polygon:&nbsp;&quot;&nbsp;(kind-type&nbsp;o)))))
                 </span><br/>
 <span class="not-covered" title="0 out of 9 forms covered">
-                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce&nbsp;+&nbsp;(map&nbsp;e&#x2F;length&nbsp;(path-&gt;edges&nbsp;path)))
+                045&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;(dissoc&nbsp;o&nbsp;:vertices)
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:kind&nbsp;:path
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;`concat`&nbsp;rather&nbsp;than&nbsp;`conj`&nbsp;because&nbsp;order&nbsp;matters.
+                </span><br/>
+<span class="not-covered" title="0 out of 12 forms covered">
+                048&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:vertices&nbsp;(concat&nbsp;(:vertices&nbsp;o)&nbsp;(list&nbsp;(first&nbsp;(:vertices&nbsp;o))))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                049&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                050&nbsp;&nbsp;(defn&nbsp;path-&gt;edges
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                051&nbsp;&nbsp;&nbsp;&nbsp;&quot;if&nbsp;`o`&nbsp;is&nbsp;a&nbsp;path,&nbsp;a&nbsp;polygon,&nbsp;or&nbsp;a&nbsp;sequence&nbsp;of&nbsp;vertices,&nbsp;return&nbsp;a&nbsp;sequence&nbsp;of
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                052&nbsp;&nbsp;&nbsp;&nbsp;edges&nbsp;representing&nbsp;that&nbsp;path,&nbsp;polygon&nbsp;or&nbsp;sequence.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                053&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                054&nbsp;&nbsp;&nbsp;&nbsp;Throws&nbsp;`IllegalArgumentException`&nbsp;if&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;path,&nbsp;a&nbsp;polygon,&nbsp;or
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                055&nbsp;&nbsp;&nbsp;&nbsp;sequence&nbsp;of&nbsp;vertices.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                056&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Not&nbsp;a&nbsp;path!&quot;))))
+                057&nbsp;&nbsp;&nbsp;&nbsp;(cond
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(seq?&nbsp;o)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(first&nbsp;o))
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;(first&nbsp;(rest&nbsp;o))))
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;TODO:&nbsp;think&nbsp;about:&nbsp;when&nbsp;constructing&nbsp;an&nbsp;edge&nbsp;from&nbsp;a&nbsp;path,&nbsp;should&nbsp;the
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;constructed&nbsp;edge&nbsp;be&nbsp;tagged&nbsp;with&nbsp;the&nbsp;tags&nbsp;of&nbsp;the&nbsp;path?
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e&#x2F;edge&nbsp;(first&nbsp;o)&nbsp;(rest&nbsp;o))
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path-&gt;edges&nbsp;(rest&nbsp;o))))
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path?&nbsp;o)
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                069&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path-&gt;edges&nbsp;(:vertices&nbsp;o))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                070&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                071&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;Not&nbsp;a&nbsp;path&nbsp;or&nbsp;sequence&nbsp;of&nbsp;vertices!&quot;))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                073&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                074&nbsp;&nbsp;(defn&nbsp;length
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                075&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;length&nbsp;of&nbsp;this&nbsp;path,&nbsp;in&nbsp;metres.&nbsp;**Note&nbsp;that**
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                076&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;This&nbsp;is&nbsp;not&nbsp;the&nbsp;same&nbsp;as&nbsp;the&nbsp;distance&nbsp;from&nbsp;the&nbsp;start&nbsp;to&nbsp;the&nbsp;end&nbsp;of&nbsp;the
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                077&nbsp;&nbsp;&nbsp;&nbsp;path,&nbsp;which,&nbsp;except&nbsp;for&nbsp;absolutely&nbsp;straight&nbsp;paths,&nbsp;will&nbsp;be&nbsp;shorter;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                078&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;It&nbsp;is&nbsp;not&nbsp;even&nbsp;quite&nbsp;the&nbsp;same&nbsp;as&nbsp;the&nbsp;length&nbsp;of&nbsp;the&nbsp;path&nbsp;*as&nbsp;rendered*,
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                079&nbsp;&nbsp;&nbsp;&nbsp;since&nbsp;paths&nbsp;will&nbsp;generally&nbsp;be&nbsp;rendered&nbsp;as&nbsp;spline&nbsp;curves.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                080&nbsp;&nbsp;&nbsp;&nbsp;[path]
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                081&nbsp;&nbsp;&nbsp;&nbsp;(if
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(path?&nbsp;path)
+                </span><br/>
+<span class="not-covered" title="0 out of 9 forms covered">
+                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce&nbsp;+&nbsp;(map&nbsp;e&#x2F;length&nbsp;(path-&gt;edges&nbsp;path)))
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Not&nbsp;a&nbsp;path!&quot;))))
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/polygon.clj.html b/docs/cloverage/walkmap/polygon.clj.html
index 2bb0272..9eae563 100644
--- a/docs/cloverage/walkmap/polygon.clj.html
+++ b/docs/cloverage/walkmap/polygon.clj.html
@@ -11,55 +11,259 @@
                 002&nbsp;&nbsp;&nbsp;&nbsp;&quot;Essentially&nbsp;the&nbsp;specification&nbsp;for&nbsp;things&nbsp;we&nbsp;shall&nbsp;consider&nbsp;to&nbsp;be&nbsp;polygons.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                003&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[vertex?]]))
+                003&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.string&nbsp;:as&nbsp;s]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                004&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.edge&nbsp;:as&nbsp;e]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                005&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.tag&nbsp;:as&nbsp;t]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:refer&nbsp;[kind-type]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[vertex&nbsp;vertex?]]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                004&nbsp;&nbsp;
+                008&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                005&nbsp;&nbsp;(defn&nbsp;polygon?
+                009&nbsp;&nbsp;(defn&nbsp;polygon?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                006&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;polygon.&nbsp;A&nbsp;polygon&nbsp;shall&nbsp;be&nbsp;a
+                010&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;polygon.&nbsp;A&nbsp;polygon&nbsp;shall&nbsp;be&nbsp;a
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                007&nbsp;&nbsp;&nbsp;&nbsp;map&nbsp;which&nbsp;has&nbsp;a&nbsp;value&nbsp;for&nbsp;the&nbsp;key&nbsp;`:vertices`,&nbsp;where&nbsp;that&nbsp;value&nbsp;is&nbsp;a&nbsp;sequence
+                011&nbsp;&nbsp;&nbsp;&nbsp;map&nbsp;which&nbsp;has&nbsp;a&nbsp;value&nbsp;for&nbsp;the&nbsp;key&nbsp;`:vertices`,&nbsp;where&nbsp;that&nbsp;value&nbsp;is&nbsp;a&nbsp;sequence
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                008&nbsp;&nbsp;&nbsp;&nbsp;of&nbsp;vertices.&quot;
+                012&nbsp;&nbsp;&nbsp;&nbsp;of&nbsp;vertices.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                009&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                013&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                010&nbsp;&nbsp;&nbsp;&nbsp;(let
+                014&nbsp;&nbsp;&nbsp;&nbsp;(let
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[v&nbsp;(:vertices&nbsp;o)]
+                015&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[v&nbsp;(:vertices&nbsp;o)]
                 </span><br/>
 <span class="partial" title="17 out of 22 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                016&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(coll?&nbsp;v)
+                017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(coll?&nbsp;v)
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                014&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(count&nbsp;v)&nbsp;2)
+                018&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&gt;&nbsp;(count&nbsp;v)&nbsp;2)
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                015&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;vertex?&nbsp;v)
+                019&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;vertex?&nbsp;v)
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                016&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:id&nbsp;o)
+                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:polygon)))))
+                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:polygon)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                018&nbsp;&nbsp;
+                022&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                023&nbsp;&nbsp;(defn&nbsp;triangle?
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                024&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;triangle.&nbsp;A&nbsp;triangle&nbsp;shall&nbsp;be&nbsp;a
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                025&nbsp;&nbsp;&nbsp;&nbsp;polygon&nbsp;with&nbsp;exactly&nbsp;three&nbsp;vertices.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                026&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                </span><br/>
+<span class="partial" title="5 out of 6 forms covered">
+                027&nbsp;&nbsp;&nbsp;&nbsp;(and
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                028&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(coll?&nbsp;o)
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(=&nbsp;(count&nbsp;(:vertices&nbsp;o))&nbsp;3)))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                019&nbsp;&nbsp;
+                030&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                031&nbsp;&nbsp;(defn&nbsp;polygon
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                032&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;polygon&nbsp;constructed&nbsp;from&nbsp;these&nbsp;`vertices`.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                033&nbsp;&nbsp;&nbsp;&nbsp;[vertices]
+                </span><br/>
+<span class="not-covered" title="0 out of 7 forms covered">
+                034&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(every?&nbsp;vertex?&nbsp;vertices)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                035&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                037&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;Each&nbsp;item&nbsp;on&nbsp;vertices&nbsp;must&nbsp;be&nbsp;a&nbsp;vertex:&nbsp;&quot;
+                </span><br/>
+<span class="not-covered" title="0 out of 10 forms covered">
+                038&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;kind-type&nbsp;(remove&nbsp;vertex?&nbsp;vertices)))))))
+                </span><br/>
+<span class="not-covered" title="0 out of 11 forms covered">
+                039&nbsp;&nbsp;&nbsp;&nbsp;{:vertices&nbsp;vertices&nbsp;:walkmap.id&#x2F;id&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;poly&quot;))&nbsp;:kind&nbsp;:polygon})
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                040&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                041&nbsp;&nbsp;(defn&nbsp;gradient
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                042&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;polygon&nbsp;like&nbsp;`triangle`&nbsp;but&nbsp;with&nbsp;a&nbsp;key&nbsp;`:gradient`&nbsp;whose&nbsp;value&nbsp;is&nbsp;a
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                043&nbsp;&nbsp;&nbsp;&nbsp;unit&nbsp;vector&nbsp;representing&nbsp;the&nbsp;gradient&nbsp;across&nbsp;`triangle`.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                044&nbsp;&nbsp;&nbsp;&nbsp;[triangle]
+                </span><br/>
+<span class="partial" title="5 out of 6 forms covered">
+                045&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(triangle?&nbsp;triangle)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;[&quot;Must&nbsp;be&nbsp;a&nbsp;triangle:&quot;&nbsp;(kind-type&nbsp;triangle)]))))
+                </span><br/>
+<span class="covered" title="15 out of 15 forms covered">
+                048&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[order&nbsp;(sort&nbsp;#(max&nbsp;(:z&nbsp;%1)&nbsp;(:z&nbsp;%2))&nbsp;(:vertices&nbsp;triangle))
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                049&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;highest&nbsp;(first&nbsp;order)
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                050&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;lowest&nbsp;(last&nbsp;order)]
+                </span><br/>
+<span class="covered" title="10 out of 10 forms covered">
+                051&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;triangle&nbsp;:gradient&nbsp;(e&#x2F;unit-vector&nbsp;(e&#x2F;edge&nbsp;lowest&nbsp;highest)))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                052&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                053&nbsp;&nbsp;(defn&nbsp;triangle-centre
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                054&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;canonicalised&nbsp;`facet`&nbsp;(i.e.&nbsp;a&nbsp;triangular&nbsp;polygon)&nbsp;with&nbsp;an&nbsp;added
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                055&nbsp;&nbsp;&nbsp;&nbsp;key&nbsp;`:centre`&nbsp;whose&nbsp;value&nbsp;represents&nbsp;the&nbsp;centre&nbsp;of&nbsp;this&nbsp;facet&nbsp;in&nbsp;3
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                056&nbsp;&nbsp;&nbsp;&nbsp;dimensions.&nbsp;This&nbsp;only&nbsp;works&nbsp;for&nbsp;triangles,&nbsp;so&nbsp;is&nbsp;here&nbsp;not&nbsp;in
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                057&nbsp;&nbsp;&nbsp;&nbsp;`walkmap.polygon`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(although&nbsp;no&nbsp;exception&nbsp;is&nbsp;currently
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                058&nbsp;&nbsp;&nbsp;&nbsp;thrown)&nbsp;if&nbsp;the&nbsp;object&nbsp;past&nbsp;is&nbsp;not&nbsp;a&nbsp;triangular&nbsp;polygon.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                059&nbsp;&nbsp;&nbsp;&nbsp;[facet]
+                </span><br/>
+<span class="partial" title="5 out of 6 forms covered">
+                060&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(triangle?&nbsp;facet)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;[&quot;Must&nbsp;be&nbsp;a&nbsp;triangle:&quot;&nbsp;(kind-type&nbsp;facet)]))))
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                063&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[vs&nbsp;(:vertices&nbsp;facet)
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;v1&nbsp;(first&nbsp;vs)
+                </span><br/>
+<span class="covered" title="10 out of 10 forms covered">
+                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;opposite&nbsp;(e&#x2F;edge&nbsp;(nth&nbsp;vs&nbsp;1)&nbsp;(nth&nbsp;vs&nbsp;2))
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;oc&nbsp;(e&#x2F;centre&nbsp;opposite)]
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;facet
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                069&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:centre
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                070&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex
+                </span><br/>
+<span class="covered" title="16 out of 16 forms covered">
+                071&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:x&nbsp;v1)&nbsp;(*&nbsp;(-&nbsp;(:x&nbsp;oc)&nbsp;(:x&nbsp;v1))&nbsp;2&#x2F;3))
+                </span><br/>
+<span class="covered" title="16 out of 16 forms covered">
+                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:y&nbsp;v1)&nbsp;(*&nbsp;(-&nbsp;(:y&nbsp;oc)&nbsp;(:y&nbsp;v1))&nbsp;2&#x2F;3))
+                </span><br/>
+<span class="covered" title="16 out of 16 forms covered">
+                073&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:z&nbsp;v1)&nbsp;(*&nbsp;(-&nbsp;(:z&nbsp;oc)&nbsp;(:z&nbsp;v1))&nbsp;2&#x2F;3))))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                074&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                075&nbsp;&nbsp;(defn&nbsp;centre
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                076&nbsp;&nbsp;&nbsp;&nbsp;[poly]
+                </span><br/>
+<span class="partial" title="5 out of 6 forms covered">
+                077&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(polygon?&nbsp;poly)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;[&quot;Must&nbsp;be&nbsp;a&nbsp;polygon:&quot;&nbsp;(kind-type&nbsp;poly)]))))
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                080&nbsp;&nbsp;&nbsp;&nbsp;(case&nbsp;(count&nbsp;(:vertices&nbsp;poly))
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                081&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3&nbsp;(triangle-centre&nbsp;poly)
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;else
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(UnsupportedOperationException.
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;The&nbsp;general&nbsp;case&nbsp;of&nbsp;centre&nbsp;for&nbsp;polygons&nbsp;is&nbsp;not&nbsp;yet&nbsp;implemented.&quot;))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                086&nbsp;&nbsp;
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                087&nbsp;&nbsp;
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/read_svg.clj.html b/docs/cloverage/walkmap/read_svg.clj.html
new file mode 100644
index 0000000..0fd16df
--- /dev/null
+++ b/docs/cloverage/walkmap/read_svg.clj.html
@@ -0,0 +1,299 @@
+<html>
+ <head>
+   <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+  <link rel="stylesheet" href="../coverage.css"/>  <title> walkmap/read_svg.clj </title>
+ </head>
+ <body>
+<span class="covered" title="1 out of 1 forms covered">
+                001&nbsp;&nbsp;(ns&nbsp;walkmap.read-svg
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                002&nbsp;&nbsp;&nbsp;&nbsp;&quot;Utility&nbsp;functions&nbsp;for&nbsp;&nbsp;scalable&nbsp;vector&nbsp;graphics&nbsp;(SVG)&nbsp;into&nbsp;walkmap
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                003&nbsp;&nbsp;&nbsp;&nbsp;structures.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                004&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.data.zip&nbsp;:as&nbsp;dz]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                005&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.data.zip.xml&nbsp;:as&nbsp;zx]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.java.io&nbsp;:as&nbsp;io]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.string&nbsp;:as&nbsp;s]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.xml&nbsp;:as&nbsp;x]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                009&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.zip&nbsp;:as&nbsp;z]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                010&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                011&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.path&nbsp;:refer&nbsp;[path]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                012&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.tag&nbsp;:refer&nbsp;[tag]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:refer&nbsp;[kind-type&nbsp;truncate]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                014&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[vertex&nbsp;vertex?]]))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                015&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                016&nbsp;&nbsp;(defn&nbsp;upper-case?
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                017&nbsp;&nbsp;&nbsp;&nbsp;[s]
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                018&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;#(Character&#x2F;isUpperCase&nbsp;%)&nbsp;s))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                019&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                020&nbsp;&nbsp;(defn&nbsp;match-&gt;vertex
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                021&nbsp;&nbsp;&nbsp;&nbsp;[match-vector&nbsp;x&nbsp;y]
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                022&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(empty?&nbsp;match-vector)
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[command&nbsp;(nth&nbsp;match-vector&nbsp;1)
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;xcoord&nbsp;(read-string&nbsp;(nth&nbsp;match-vector&nbsp;2))
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                025&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ycoord&nbsp;(read-string&nbsp;(nth&nbsp;match-vector&nbsp;3))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                026&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;upper&nbsp;case&nbsp;command&nbsp;letters&nbsp;mean&nbsp;the&nbsp;coordinates&nbsp;that&nbsp;follow&nbsp;are
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                027&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;absolute;&nbsp;lower&nbsp;case,&nbsp;relative.
+                </span><br/>
+<span class="not-covered" title="0 out of 9 forms covered">
+                028&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x&#x27;&nbsp;(if&nbsp;(upper-case?&nbsp;command)&nbsp;xcoord&nbsp;(+&nbsp;x&nbsp;xcoord))
+                </span><br/>
+<span class="not-covered" title="0 out of 9 forms covered">
+                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y&#x27;&nbsp;(if&nbsp;(upper-case?&nbsp;command)&nbsp;ycoord&nbsp;(+&nbsp;y&nbsp;ycoord))]
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(case&nbsp;(s&#x2F;lower-case&nbsp;command)
+                </span><br/>
+<span class="not-covered" title="0 out of 20 forms covered">
+                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&quot;m&quot;&nbsp;&quot;l&quot;)&nbsp;{:vertex&nbsp;(vertex&nbsp;x&#x27;&nbsp;y&#x27;)&nbsp;:x&nbsp;x&#x27;&nbsp;:y&nbsp;y&#x27;}
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                032&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;nil))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                033&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                034&nbsp;&nbsp;(defn&nbsp;command-string-&gt;vertices
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                035&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;destination&nbsp;of&nbsp;each&nbsp;successive&nbsp;line&nbsp;(`l`,&nbsp;`L`)&nbsp;and&nbsp;move&nbsp;(`m`,&nbsp;`M`)
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                036&nbsp;&nbsp;&nbsp;&nbsp;command&nbsp;in&nbsp;this&nbsp;string&nbsp;`s`,&nbsp;expected&nbsp;to&nbsp;be&nbsp;an&nbsp;SVG&nbsp;path&nbsp;command&nbsp;string.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                037&nbsp;&nbsp;&nbsp;&nbsp;[s]
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                038&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[cmd-matcher&nbsp;;;&nbsp;matches&nbsp;a&nbsp;&#x27;command&#x27;&nbsp;in&nbsp;the&nbsp;string:&nbsp;a&nbsp;letter&nbsp;followed&nbsp;by
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                039&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;spaces&nbsp;and&nbsp;numbers
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                040&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(re-matcher&nbsp;#&quot;[a-zA-Z][^a-zA-Z]*&quot;&nbsp;s)
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;seg-pattern&nbsp;;;&nbsp;matches&nbsp;a&nbsp;command&nbsp;which&nbsp;initiates&nbsp;a&nbsp;move&nbsp;of&nbsp;the&nbsp;current
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;position.
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#&quot;([a-zA-Z])&nbsp;+([-+]?[0-9]*\.?[0-9]+)&nbsp;+([-+]?[0-9]*\.?[0-9]+)&nbsp;+&quot;]
+                </span><br/>
+<span class="not-covered" title="0 out of 11 forms covered">
+                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(loop&nbsp;[match&nbsp;(re-find&nbsp;cmd-matcher)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;result&nbsp;[]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x&nbsp;0
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;y&nbsp;0]
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                048&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if-not&nbsp;match
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                049&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(filter&nbsp;vertex?&nbsp;result)
+                </span><br/>
+<span class="not-covered" title="0 out of 18 forms covered">
+                050&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[m&nbsp;(match-&gt;vertex&nbsp;(re-find&nbsp;seg-pattern&nbsp;match)&nbsp;x&nbsp;y)]
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                051&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(recur&nbsp;(re-find&nbsp;cmd-matcher)&nbsp;&nbsp;&nbsp;&nbsp;;loop&nbsp;with&nbsp;2&nbsp;new&nbsp;arguments
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                052&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(conj&nbsp;result&nbsp;(:vertex&nbsp;m))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                053&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(:x&nbsp;m)&nbsp;x)
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(:y&nbsp;m)&nbsp;y)))))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                055&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                056&nbsp;&nbsp;(defn&nbsp;path-elt-&gt;path
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                057&nbsp;&nbsp;&nbsp;&nbsp;&quot;Given&nbsp;the&nbsp;SVG&nbsp;path&nbsp;element&nbsp;`elt`,&nbsp;return&nbsp;a&nbsp;walkmap&nbsp;path&nbsp;structure
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                058&nbsp;&nbsp;&nbsp;&nbsp;representing&nbsp;the&nbsp;line&nbsp;(`l`,&nbsp;`L`)&nbsp;and&nbsp;move&nbsp;(`m`,&nbsp;`M`)&nbsp;commands&nbsp;in
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                059&nbsp;&nbsp;&nbsp;&nbsp;that&nbsp;path.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                060&nbsp;&nbsp;&nbsp;&nbsp;[elt]
+                </span><br/>
+<span class="not-covered" title="0 out of 7 forms covered">
+                061&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(=&nbsp;(:tag&nbsp;elt)&nbsp;:path)
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[vs&nbsp;(command-string-&gt;vertices&nbsp;(-&gt;&nbsp;elt&nbsp;:attrs&nbsp;:d))
+                </span><br/>
+<span class="not-covered" title="0 out of 10 forms covered">
+                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p&nbsp;&nbsp;(when-not&nbsp;(empty?&nbsp;vs)&nbsp;(apply&nbsp;path&nbsp;vs))]
+                </span><br/>
+<span class="not-covered" title="0 out of 11 forms covered">
+                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(and&nbsp;p&nbsp;(-&gt;&nbsp;elt&nbsp;:attrs&nbsp;:class))
+                </span><br/>
+<span class="not-covered" title="0 out of 14 forms covered">
+                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(tag&nbsp;p&nbsp;(map&nbsp;keyword&nbsp;(s&#x2F;split&nbsp;(-&gt;&nbsp;elt&nbsp;:attrs&nbsp;:class)&nbsp;#&quot;&nbsp;&quot;)))
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;p))
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;an&nbsp;SVG&nbsp;`path`&nbsp;element:&nbsp;&quot;&nbsp;elt)))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                069&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                070&nbsp;&nbsp;(defn&nbsp;progeny
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                071&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;all&nbsp;the&nbsp;nodes&nbsp;in&nbsp;the&nbsp;XML&nbsp;structure&nbsp;below&nbsp;this&nbsp;`elt`&nbsp;which&nbsp;match
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                072&nbsp;&nbsp;&nbsp;&nbsp;this&nbsp;`predicate`.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                073&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;the&nbsp;name&nbsp;`descendants`&nbsp;is&nbsp;bound&nbsp;in&nbsp;`clojure.core`&nbsp;for&nbsp;something&nbsp;quite
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                074&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;different,&nbsp;and&nbsp;I&nbsp;chose&nbsp;not&nbsp;to&nbsp;rebind&nbsp;it.
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                075&nbsp;&nbsp;&nbsp;&nbsp;[elt&nbsp;predicate]
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                076&nbsp;&nbsp;&nbsp;&nbsp;(if
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(apply&nbsp;predicate&nbsp;(list&nbsp;elt))
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(list&nbsp;elt)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                080&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;concat
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                081&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(remove
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;empty?
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(progeny&nbsp;%&nbsp;predicate)
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:content&nbsp;elt))))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                086&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                087&nbsp;&nbsp;(defn&nbsp;read-svg
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                088&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;I&nbsp;tried&nbsp;to&nbsp;get&nbsp;this&nbsp;working&nbsp;with&nbsp;all&nbsp;the&nbsp;clever&nbsp;zip&nbsp;stuff&nbsp;in
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                089&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;`clojure.zip`,&nbsp;`clojure.data.zip`,&nbsp;and&nbsp;so&nbsp;on.&nbsp;It&nbsp;would&nbsp;probably&nbsp;have
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                090&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;been&nbsp;more&nbsp;elegant,&nbsp;but&nbsp;it&nbsp;kept&nbsp;crashing&nbsp;out&nbsp;of&nbsp;heap&nbsp;space&nbsp;on&nbsp;even
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                091&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;quite&nbsp;small&nbsp;XML&nbsp;files.&nbsp;So&nbsp;I&#x27;ve&nbsp;implemented&nbsp;my&nbsp;own&nbsp;solution.
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                092&nbsp;&nbsp;&nbsp;&nbsp;([file-name]
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                093&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(read-svg&nbsp;file-name&nbsp;nil))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                094&nbsp;&nbsp;&nbsp;&nbsp;([file-name&nbsp;map-kind]
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                095&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[xml&nbsp;(x&#x2F;parse&nbsp;(io&#x2F;file&nbsp;file-name))
+                </span><br/>
+<span class="not-covered" title="0 out of 10 forms covered">
+                096&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;paths&nbsp;(progeny&nbsp;xml&nbsp;#(=&nbsp;(:tag&nbsp;%)&nbsp;:path))]
+                </span><br/>
+<span class="not-covered" title="0 out of 7 forms covered">
+                097&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(remove&nbsp;nil?&nbsp;(map&nbsp;path-elt-&gt;path&nbsp;paths)))))
+                </span><br/>
+ </body>
+</html>
diff --git a/docs/cloverage/walkmap/routing.clj.html b/docs/cloverage/walkmap/routing.clj.html
new file mode 100644
index 0000000..ea31cf3
--- /dev/null
+++ b/docs/cloverage/walkmap/routing.clj.html
@@ -0,0 +1,62 @@
+<html>
+ <head>
+   <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+  <link rel="stylesheet" href="../coverage.css"/>  <title> walkmap/routing.clj </title>
+ </head>
+ <body>
+<span class="covered" title="1 out of 1 forms covered">
+                001&nbsp;&nbsp;(ns&nbsp;walkmap.routing
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                002&nbsp;&nbsp;&nbsp;&nbsp;&quot;Finding&nbsp;optimal&nbsp;routes&nbsp;to&nbsp;traverse&nbsp;a&nbsp;map.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                003&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[walkmap.path&nbsp;:as&nbsp;p]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                004&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:as&nbsp;q]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                005&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.stl&nbsp;:as&nbsp;s]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:as&nbsp;u]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:as&nbsp;v]))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                008&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                009&nbsp;&nbsp;;;&nbsp;Breadth&nbsp;first&nbsp;search&nbsp;is&nbsp;a&nbsp;good&nbsp;algorithm&nbsp;for&nbsp;terrain&nbsp;in&nbsp;which&nbsp;all&nbsp;steps&nbsp;have
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                010&nbsp;&nbsp;;;&nbsp;equal,&nbsp;but&nbsp;in&nbsp;our&nbsp;world&nbsp;(like&nbsp;the&nbsp;real&nbsp;world),&nbsp;they&nbsp;don&#x27;t.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                011&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                012&nbsp;&nbsp;;;&nbsp;Reading&nbsp;list:
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                013&nbsp;&nbsp;;;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                014&nbsp;&nbsp;;;&nbsp;https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;A*_search_algorithm
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                015&nbsp;&nbsp;;;&nbsp;https:&#x2F;&#x2F;www.redblobgames.com&#x2F;pathfinding&#x2F;a-star&#x2F;introduction.html
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                016&nbsp;&nbsp;;;&nbsp;https:&#x2F;&#x2F;faculty.nps.edu&#x2F;ncrowe&#x2F;opmpaper2.htm
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                017&nbsp;&nbsp;;;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                018&nbsp;&nbsp;;;&nbsp;See&nbsp;https:&#x2F;&#x2F;simon-brooke.github.io&#x2F;the-great-game&#x2F;codox&#x2F;Pathmaking.html
+                </span><br/>
+ </body>
+</html>
diff --git a/docs/cloverage/walkmap/stl.clj.html b/docs/cloverage/walkmap/stl.clj.html
index 0684c28..5240aa8 100644
--- a/docs/cloverage/walkmap/stl.clj.html
+++ b/docs/cloverage/walkmap/stl.clj.html
@@ -23,559 +23,604 @@
                 006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[org.clojars.smee.binary.core&nbsp;:as&nbsp;b]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l&nbsp;:refer&nbsp;[info&nbsp;error&nbsp;spy]]
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
                 008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.edge&nbsp;:as&nbsp;e]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                009&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:refer&nbsp;[polygon?]]
+                009&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.ocean&nbsp;:as&nbsp;o]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                010&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.tag&nbsp;:refer&nbsp;[tag]]
+                010&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:refer&nbsp;[centre&nbsp;gradient&nbsp;polygon?]]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:as&nbsp;v])
+                011&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.superstructure&nbsp;:refer&nbsp;[store]]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;(:import&nbsp;org.clojars.smee.binary.core.BinaryIO
+                012&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.tag&nbsp;:refer&nbsp;[tag]]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;java.io.DataInput))
+                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:as&nbsp;u]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                014&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:as&nbsp;v])
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                015&nbsp;&nbsp;&nbsp;&nbsp;(:import&nbsp;org.clojars.smee.binary.core.BinaryIO
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                016&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;java.io.DataInput))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                014&nbsp;&nbsp;
+                017&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                015&nbsp;&nbsp;(defn&nbsp;stl?
+                018&nbsp;&nbsp;(defn&nbsp;stl?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                016&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;is&nbsp;recogniseable&nbsp;as&nbsp;an&nbsp;STL&nbsp;structure.&nbsp;An&nbsp;STL&nbsp;structure&nbsp;must
+                019&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;is&nbsp;recogniseable&nbsp;as&nbsp;an&nbsp;STL&nbsp;structure.&nbsp;An&nbsp;STL&nbsp;structure&nbsp;must
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                017&nbsp;&nbsp;&nbsp;&nbsp;have&nbsp;a&nbsp;key&nbsp;`:facets`,&nbsp;whose&nbsp;value&nbsp;must&nbsp;be&nbsp;a&nbsp;sequence&nbsp;of&nbsp;polygons;&nbsp;and
+                020&nbsp;&nbsp;&nbsp;&nbsp;have&nbsp;a&nbsp;key&nbsp;`:facets`,&nbsp;whose&nbsp;value&nbsp;must&nbsp;be&nbsp;a&nbsp;sequence&nbsp;of&nbsp;polygons;&nbsp;and
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                018&nbsp;&nbsp;&nbsp;&nbsp;may&nbsp;have&nbsp;a&nbsp;key&nbsp;`:header`&nbsp;whose&nbsp;value&nbsp;should&nbsp;be&nbsp;a&nbsp;string,&nbsp;and&#x2F;or&nbsp;a&nbsp;key
+                021&nbsp;&nbsp;&nbsp;&nbsp;may&nbsp;have&nbsp;a&nbsp;key&nbsp;`:header`&nbsp;whose&nbsp;value&nbsp;should&nbsp;be&nbsp;a&nbsp;string,&nbsp;and&#x2F;or&nbsp;a&nbsp;key
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                019&nbsp;&nbsp;&nbsp;&nbsp;`:count`,&nbsp;whose&nbsp;value&nbsp;should&nbsp;be&nbsp;a&nbsp;positive&nbsp;integer.
+                022&nbsp;&nbsp;&nbsp;&nbsp;`:count`,&nbsp;whose&nbsp;value&nbsp;should&nbsp;be&nbsp;a&nbsp;positive&nbsp;integer.
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                020&nbsp;&nbsp;
+                023&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                021&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`verify-count?`&nbsp;is&nbsp;passed&nbsp;and&nbsp;is&nbsp;not&nbsp;`false`,&nbsp;verify&nbsp;that&nbsp;the&nbsp;value&nbsp;of
+                024&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`verify-count?`&nbsp;is&nbsp;passed&nbsp;and&nbsp;is&nbsp;not&nbsp;`false`,&nbsp;verify&nbsp;that&nbsp;the&nbsp;value&nbsp;of
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                022&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;`:count`&nbsp;header&nbsp;is&nbsp;equal&nbsp;to&nbsp;the&nbsp;number&nbsp;of&nbsp;facets.&quot;
+                025&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;`:count`&nbsp;header&nbsp;is&nbsp;equal&nbsp;to&nbsp;the&nbsp;number&nbsp;of&nbsp;facets.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                023&nbsp;&nbsp;&nbsp;&nbsp;([o]
+                026&nbsp;&nbsp;&nbsp;&nbsp;([o]
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl?&nbsp;o&nbsp;false))
+                027&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl?&nbsp;o&nbsp;false))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                025&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;verify-count?]
+                028&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;verify-count?]
                 </span><br/>
 <span class="partial" title="20 out of 26 forms covered">
-                026&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                027&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
+                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                028&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;o)
+                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;o)
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;polygon?&nbsp;(:facets&nbsp;o))
+                032&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;polygon?&nbsp;(:facets&nbsp;o))
                 </span><br/>
 <span class="partial" title="9 out of 10 forms covered">
-                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(:header&nbsp;o)&nbsp;(string?&nbsp;(:header&nbsp;o))&nbsp;true)
+                033&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(:header&nbsp;o)&nbsp;(string?&nbsp;(:header&nbsp;o))&nbsp;true)
                 </span><br/>
 <span class="partial" title="9 out of 10 forms covered">
-                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(:count&nbsp;o)&nbsp;(integer?&nbsp;(:count&nbsp;o))&nbsp;true)
+                034&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(:count&nbsp;o)&nbsp;(integer?&nbsp;(:count&nbsp;o))&nbsp;true)
                 </span><br/>
 <span class="partial" title="14 out of 15 forms covered">
-                032&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:stl))
+                035&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:stl))
                 </span><br/>
 <span class="partial" title="1 out of 11 forms covered">
-                033&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;verify-count?&nbsp;(=&nbsp;(:count&nbsp;o)&nbsp;(count&nbsp;(:facets&nbsp;o)))&nbsp;true))))
+                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;verify-count?&nbsp;(=&nbsp;(:count&nbsp;o)&nbsp;(count&nbsp;(:facets&nbsp;o)))&nbsp;true))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                034&nbsp;&nbsp;
+                037&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                035&nbsp;&nbsp;(def&nbsp;vect
+                038&nbsp;&nbsp;(def&nbsp;vect
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                036&nbsp;&nbsp;&nbsp;&nbsp;&quot;A&nbsp;codec&nbsp;for&nbsp;vectors&nbsp;within&nbsp;a&nbsp;binary&nbsp;STL&nbsp;file.&quot;
+                039&nbsp;&nbsp;&nbsp;&nbsp;&quot;A&nbsp;codec&nbsp;for&nbsp;vectors&nbsp;within&nbsp;a&nbsp;binary&nbsp;STL&nbsp;file.&quot;
                 </span><br/>
 <span class="covered" title="8 out of 8 forms covered">
-                037&nbsp;&nbsp;&nbsp;&nbsp;(b&#x2F;ordered-map
+                040&nbsp;&nbsp;&nbsp;&nbsp;(b&#x2F;ordered-map
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                038&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:x&nbsp;:float-le
+                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:x&nbsp;:float-le
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                039&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:y&nbsp;:float-le
+                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:y&nbsp;:float-le
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                040&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:z&nbsp;:float-le))
+                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:z&nbsp;:float-le))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                041&nbsp;&nbsp;
+                044&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                042&nbsp;&nbsp;(def&nbsp;facet
+                045&nbsp;&nbsp;(def&nbsp;facet
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                043&nbsp;&nbsp;&nbsp;&nbsp;&quot;A&nbsp;codec&nbsp;for&nbsp;a&nbsp;facet&nbsp;(triangle)&nbsp;within&nbsp;a&nbsp;binary&nbsp;STL&nbsp;file.&quot;
+                046&nbsp;&nbsp;&nbsp;&nbsp;&quot;A&nbsp;codec&nbsp;for&nbsp;a&nbsp;facet&nbsp;(triangle)&nbsp;within&nbsp;a&nbsp;binary&nbsp;STL&nbsp;file.&quot;
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                044&nbsp;&nbsp;&nbsp;&nbsp;(b&#x2F;ordered-map
+                047&nbsp;&nbsp;&nbsp;&nbsp;(b&#x2F;ordered-map
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:normal&nbsp;vect
+                048&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:normal&nbsp;vect
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:vertices&nbsp;[vect&nbsp;vect&nbsp;vect]
+                049&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:vertices&nbsp;[vect&nbsp;vect&nbsp;vect]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:abc&nbsp;:ushort-le))
+                050&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:abc&nbsp;:ushort-le))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                048&nbsp;&nbsp;
+                051&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                049&nbsp;&nbsp;(def&nbsp;binary-stl
+                052&nbsp;&nbsp;(def&nbsp;binary-stl
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                050&nbsp;&nbsp;&nbsp;&nbsp;&quot;A&nbsp;codec&nbsp;for&nbsp;binary&nbsp;STL&nbsp;files&quot;
+                053&nbsp;&nbsp;&nbsp;&nbsp;&quot;A&nbsp;codec&nbsp;for&nbsp;binary&nbsp;STL&nbsp;files&quot;
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                051&nbsp;&nbsp;&nbsp;&nbsp;(b&#x2F;ordered-map
+                054&nbsp;&nbsp;&nbsp;&nbsp;(b&#x2F;ordered-map
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                052&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:header&nbsp;(b&#x2F;string&nbsp;&quot;ISO-8859-1&quot;&nbsp;:length&nbsp;80)&nbsp;;;&nbsp;for&nbsp;the&nbsp;time&nbsp;being&nbsp;we&nbsp;neither&nbsp;know&nbsp;nor&nbsp;care&nbsp;what&#x27;s&nbsp;in&nbsp;this.
+                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:header&nbsp;(b&#x2F;string&nbsp;&quot;ISO-8859-1&quot;&nbsp;:length&nbsp;80)&nbsp;;;&nbsp;for&nbsp;the&nbsp;time&nbsp;being&nbsp;we&nbsp;neither&nbsp;know&nbsp;nor&nbsp;care&nbsp;what&#x27;s&nbsp;in&nbsp;this.
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                053&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:count&nbsp;:uint-le
+                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:count&nbsp;:uint-le
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:facets&nbsp;(b&#x2F;repeated&nbsp;facet)))
+                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:facets&nbsp;(b&#x2F;repeated&nbsp;facet)))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                055&nbsp;&nbsp;
+                058&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                056&nbsp;&nbsp;(defn&nbsp;centre
+                059&nbsp;&nbsp;(defn&nbsp;canonicalise
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                057&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;canonicalised&nbsp;`facet`&nbsp;(i.e.&nbsp;a&nbsp;triangular&nbsp;polygon)&nbsp;with&nbsp;an&nbsp;added
+                060&nbsp;&nbsp;&nbsp;&nbsp;&quot;Objects&nbsp;read&nbsp;in&nbsp;from&nbsp;STL&nbsp;won&#x27;t&nbsp;have&nbsp;all&nbsp;the&nbsp;keys&#x2F;values&nbsp;we&nbsp;need&nbsp;them&nbsp;to&nbsp;have.
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                058&nbsp;&nbsp;&nbsp;&nbsp;key&nbsp;`:centre`&nbsp;whose&nbsp;value&nbsp;represents&nbsp;the&nbsp;centre&nbsp;of&nbsp;this&nbsp;facet&nbsp;in&nbsp;3
+                061&nbsp;&nbsp;&nbsp;&nbsp;`o`&nbsp;may&nbsp;be&nbsp;a&nbsp;map&nbsp;(representing&nbsp;a&nbsp;facet&nbsp;or&nbsp;a&nbsp;vertex),&nbsp;or&nbsp;a&nbsp;sequence&nbsp;of&nbsp;such&nbsp;maps;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                059&nbsp;&nbsp;&nbsp;&nbsp;dimensions.&nbsp;This&nbsp;only&nbsp;works&nbsp;for&nbsp;triangles,&nbsp;so&nbsp;is&nbsp;here&nbsp;not&nbsp;in
+                062&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;it&nbsp;isn&#x27;t&nbsp;recognised&nbsp;it&nbsp;is&nbsp;at&nbsp;present&nbsp;just&nbsp;returned&nbsp;unchanged.&nbsp;`map-kind`,&nbsp;if
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                060&nbsp;&nbsp;&nbsp;&nbsp;`walkmap.polygon`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(although&nbsp;no&nbsp;exception&nbsp;is&nbsp;currently
+                063&nbsp;&nbsp;&nbsp;&nbsp;passed,&nbsp;must&nbsp;be&nbsp;a&nbsp;keyword&nbsp;indicating&nbsp;the&nbsp;value&nbsp;represented&nbsp;by&nbsp;the&nbsp;`z`&nbsp;axis
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                061&nbsp;&nbsp;&nbsp;&nbsp;thrown)&nbsp;if&nbsp;the&nbsp;object&nbsp;past&nbsp;is&nbsp;not&nbsp;a&nbsp;triangular&nbsp;polygon.&quot;
+                064&nbsp;&nbsp;&nbsp;&nbsp;(defaults&nbsp;to&nbsp;`:height`).&nbsp;It&nbsp;is&nbsp;an&nbsp;error,&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown,&nbsp;if
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                062&nbsp;&nbsp;&nbsp;&nbsp;[facet]
+                065&nbsp;&nbsp;&nbsp;&nbsp;`map-kind`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword.&quot;
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                063&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[vs&nbsp;(:vertices&nbsp;facet)
-                </span><br/>
-<span class="covered" title="3 out of 3 forms covered">
-                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;v1&nbsp;(first&nbsp;vs)
-                </span><br/>
-<span class="covered" title="10 out of 10 forms covered">
-                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;opposite&nbsp;(e&#x2F;edge&nbsp;(nth&nbsp;vs&nbsp;1)&nbsp;(nth&nbsp;vs&nbsp;2))
-                </span><br/>
-<span class="covered" title="3 out of 3 forms covered">
-                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;oc&nbsp;(e&#x2F;centre&nbsp;opposite)]
-                </span><br/>
-<span class="covered" title="3 out of 3 forms covered">
-                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;facet
+                066&nbsp;&nbsp;&nbsp;&nbsp;([o]&nbsp;(canonicalise&nbsp;o&nbsp;:height))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                069&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:centre
+                067&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;map-kind]
                 </span><br/>
-<span class="covered" title="2 out of 2 forms covered">
-                070&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(v&#x2F;vertex
-                </span><br/>
-<span class="covered" title="16 out of 16 forms covered">
-                071&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:x&nbsp;v1)&nbsp;(*&nbsp;(-&nbsp;(:x&nbsp;oc)&nbsp;(:x&nbsp;v1))&nbsp;2&#x2F;3))
-                </span><br/>
-<span class="covered" title="16 out of 16 forms covered">
-                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:y&nbsp;v1)&nbsp;(*&nbsp;(-&nbsp;(:y&nbsp;oc)&nbsp;(:y&nbsp;v1))&nbsp;2&#x2F;3))
-                </span><br/>
-<span class="covered" title="16 out of 16 forms covered">
-                073&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(+&nbsp;(:z&nbsp;v1)&nbsp;(*&nbsp;(-&nbsp;(:z&nbsp;oc)&nbsp;(:z&nbsp;v1))&nbsp;2&#x2F;3))))))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                074&nbsp;&nbsp;
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                075&nbsp;&nbsp;(defn&nbsp;canonicalise
+<span class="covered" title="9 out of 9 forms covered">
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(canonicalise&nbsp;o&nbsp;map-kind&nbsp;(v&#x2F;vertex&nbsp;1&nbsp;1&nbsp;1)))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                076&nbsp;&nbsp;&nbsp;&nbsp;&quot;Objects&nbsp;read&nbsp;in&nbsp;from&nbsp;STL&nbsp;won&#x27;t&nbsp;have&nbsp;all&nbsp;the&nbsp;keys&#x2F;values&nbsp;we&nbsp;need&nbsp;them&nbsp;to&nbsp;have.
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                077&nbsp;&nbsp;&nbsp;&nbsp;`o`&nbsp;may&nbsp;be&nbsp;a&nbsp;map&nbsp;(representing&nbsp;a&nbsp;facet&nbsp;or&nbsp;a&nbsp;vertex),&nbsp;or&nbsp;a&nbsp;sequence&nbsp;of&nbsp;such&nbsp;maps;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                078&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;it&nbsp;isn&#x27;t&nbsp;recognised&nbsp;it&nbsp;is&nbsp;at&nbsp;present&nbsp;just&nbsp;returned&nbsp;unchanged.&nbsp;`map-kind`,&nbsp;if
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                079&nbsp;&nbsp;&nbsp;&nbsp;passed,&nbsp;must&nbsp;be&nbsp;a&nbsp;keyword&nbsp;indicating&nbsp;the&nbsp;value&nbsp;represented&nbsp;by&nbsp;the&nbsp;`z`&nbsp;axis
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                080&nbsp;&nbsp;&nbsp;&nbsp;(defaults&nbsp;to&nbsp;`:height`).&nbsp;It&nbsp;is&nbsp;an&nbsp;error,&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown,&nbsp;if
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                081&nbsp;&nbsp;&nbsp;&nbsp;`map-kind`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword.&quot;
-                </span><br/>
-<span class="covered" title="4 out of 4 forms covered">
-                082&nbsp;&nbsp;&nbsp;&nbsp;([o]&nbsp;(canonicalise&nbsp;o&nbsp;:height))
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                083&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;map-kind]
+                069&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;map-kind&nbsp;scale-vertex]
                 </span><br/>
 <span class="partial" title="2 out of 3 forms covered">
-                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not
+                070&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(keyword?&nbsp;map-kind)
+                071&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(keyword?&nbsp;map-kind)
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                086&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="not-covered" title="0 out of 13 forms covered">
-                087&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;keyword:&nbsp;&quot;&nbsp;(or&nbsp;map-kind&nbsp;&quot;nil&quot;))&nbsp;0&nbsp;80))))
+<span class="not-covered" title="0 out of 12 forms covered">
+                073&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(u&#x2F;truncate&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;keyword:&nbsp;&quot;&nbsp;(or&nbsp;map-kind&nbsp;&quot;nil&quot;))&nbsp;80))))
                 </span><br/>
 <span class="partial" title="4 out of 5 forms covered">
-                088&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
+                074&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
                 </span><br/>
 <span class="partial" title="19 out of 20 forms covered">
-                089&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(coll?&nbsp;o)&nbsp;(not&nbsp;(map?&nbsp;o)))&nbsp;(map&nbsp;#(canonicalise&nbsp;%&nbsp;map-kind)&nbsp;o)
+                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(coll?&nbsp;o)&nbsp;(not&nbsp;(map?&nbsp;o)))&nbsp;(map&nbsp;#(canonicalise&nbsp;%&nbsp;map-kind)&nbsp;o)
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                090&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&nbsp;has&nbsp;:facets&nbsp;it&#x27;s&nbsp;an&nbsp;STL&nbsp;structure,&nbsp;but&nbsp;it&nbsp;doesn&#x27;t&nbsp;yet&nbsp;conform&nbsp;to&nbsp;`stl?`
+                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&nbsp;has&nbsp;:facets&nbsp;it&#x27;s&nbsp;an&nbsp;STL&nbsp;structure,&nbsp;but&nbsp;it&nbsp;doesn&#x27;t&nbsp;yet&nbsp;conform&nbsp;to&nbsp;`stl?`
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                091&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;o)&nbsp;(assoc&nbsp;o
+                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;o)&nbsp;(assoc&nbsp;o
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                092&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:kind&nbsp;:stl
+                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:kind&nbsp;:stl
                 </span><br/>
 <span class="partial" title="11 out of 12 forms covered">
-                093&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:id&nbsp;(or&nbsp;(:id&nbsp;o)&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;stl&quot;)))
+                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:walkmap.id&#x2F;id&nbsp;(or&nbsp;(:walkmap.id&#x2F;id&nbsp;o)&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;stl&quot;)))
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                094&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:facets&nbsp;(canonicalise&nbsp;(:facets&nbsp;o)&nbsp;map-kind))
+                080&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:facets&nbsp;(canonicalise&nbsp;(:facets&nbsp;o)&nbsp;map-kind))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                095&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&nbsp;has&nbsp;:vertices&nbsp;it&#x27;s&nbsp;a&nbsp;polygon,&nbsp;but&nbsp;it&nbsp;doesn&#x27;t&nbsp;yet&nbsp;conform&nbsp;to&nbsp;`polygon?`
+                081&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&nbsp;has&nbsp;:vertices&nbsp;it&#x27;s&nbsp;a&nbsp;polygon,&nbsp;but&nbsp;it&nbsp;may&nbsp;not&nbsp;yet&nbsp;conform&nbsp;to
                 </span><br/>
-<span class="covered" title="5 out of 5 forms covered">
-                096&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:vertices&nbsp;o)&nbsp;(centre
+<span class="not-tracked" title="0 out of 0 forms covered">
+                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;`polygon?`
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:vertices&nbsp;o)&nbsp;(let&nbsp;[f&nbsp;(gradient
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(centre
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                097&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(tag
+                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(tag
                 </span><br/>
 <span class="covered" title="7 out of 7 forms covered">
-                098&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;o
+                086&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;o
                 </span><br/>
-<span class="partial" title="11 out of 12 forms covered">
-                099&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:id&nbsp;(or&nbsp;(:id&nbsp;o)&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;poly&quot;)))
+<span class="partial" title="4 out of 5 forms covered">
+                087&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:walkmap.id&#x2F;id&nbsp;(or
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                088&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                089&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;poly&quot;)))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:kind&nbsp;:polygon
-                </span><br/>
-<span class="covered" title="6 out of 6 forms covered">
-                101&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:vertices&nbsp;(canonicalise&nbsp;(:vertices&nbsp;o)&nbsp;map-kind))
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:facet&nbsp;map-kind))
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&nbsp;has&nbsp;a&nbsp;value&nbsp;for&nbsp;:x&nbsp;it&#x27;s&nbsp;a&nbsp;vertex,&nbsp;but&nbsp;it&nbsp;doesn&#x27;t&nbsp;yet&nbsp;conform&nbsp;to&nbsp;`vertex?`
-                </span><br/>
-<span class="covered" title="6 out of 6 forms covered">
-                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:x&nbsp;o)&nbsp;(v&#x2F;canonicalise&nbsp;o)
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                105&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;shouldn&#x27;t&nbsp;happen
-                </span><br/>
-<span class="not-covered" title="0 out of 1 forms covered">
-                106&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else&nbsp;o)))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                107&nbsp;&nbsp;
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                108&nbsp;&nbsp;(defn&nbsp;decode-binary-stl
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                109&nbsp;&nbsp;&nbsp;&nbsp;&quot;Parse&nbsp;a&nbsp;binary&nbsp;STL&nbsp;file&nbsp;from&nbsp;this&nbsp;`filename`&nbsp;and&nbsp;return&nbsp;an&nbsp;STL&nbsp;structure
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                110&nbsp;&nbsp;&nbsp;&nbsp;representing&nbsp;its&nbsp;contents.&nbsp;`map-kind`,&nbsp;if&nbsp;passed,&nbsp;must&nbsp;be&nbsp;a&nbsp;keyword
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                111&nbsp;&nbsp;&nbsp;&nbsp;indicating&nbsp;the&nbsp;value&nbsp;represented&nbsp;by&nbsp;the&nbsp;`z`&nbsp;axis&nbsp;(defaults&nbsp;to&nbsp;`:height`).
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                112&nbsp;&nbsp;&nbsp;&nbsp;It&nbsp;is&nbsp;an&nbsp;error,&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown,&nbsp;if&nbsp;`map-kind`&nbsp;is&nbsp;not&nbsp;a
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                113&nbsp;&nbsp;&nbsp;&nbsp;keyword.
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                114&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                115&nbsp;&nbsp;&nbsp;&nbsp;**NOTE**&nbsp;that&nbsp;we&#x27;ve&nbsp;no&nbsp;way&nbsp;of&nbsp;verifying&nbsp;that&nbsp;the&nbsp;input&nbsp;file&nbsp;is&nbsp;binary&nbsp;STL
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                116&nbsp;&nbsp;&nbsp;&nbsp;data,&nbsp;if&nbsp;it&nbsp;is&nbsp;not&nbsp;this&nbsp;will&nbsp;run&nbsp;but&nbsp;will&nbsp;return&nbsp;garbage.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                117&nbsp;&nbsp;&nbsp;&nbsp;([filename]
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                118&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(decode-binary-stl&nbsp;filename&nbsp;:height))
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                119&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;map-kind]
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                120&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                121&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(keyword?&nbsp;map-kind)
-                </span><br/>
-<span class="not-covered" title="0 out of 2 forms covered">
-                122&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
-                </span><br/>
-<span class="not-covered" title="0 out of 13 forms covered">
-                123&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;keyword:&nbsp;&quot;&nbsp;(or&nbsp;map-kind&nbsp;&quot;nil&quot;))&nbsp;0&nbsp;80))))
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                124&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[in&nbsp;(io&#x2F;input-stream&nbsp;filename)]
-                </span><br/>
-<span class="not-covered" title="0 out of 7 forms covered">
-                125&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(canonicalise&nbsp;(b&#x2F;decode&nbsp;binary-stl&nbsp;in)&nbsp;map-kind))))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                126&nbsp;&nbsp;
+                090&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:kind&nbsp;:polygon
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                127&nbsp;&nbsp;(defn-&nbsp;vect-&gt;str&nbsp;[prefix&nbsp;v]
+                091&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:vertices&nbsp;(canonicalise
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                092&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:vertices&nbsp;o)
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                093&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;map-kind))
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                094&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:facet&nbsp;map-kind)))]
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                095&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(o&#x2F;ocean?&nbsp;f)
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                096&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(tag&nbsp;f&nbsp;:ocean&nbsp;:no-traversal)
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                097&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;f))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                098&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&nbsp;has&nbsp;a&nbsp;value&nbsp;for&nbsp;:x&nbsp;it&#x27;s&nbsp;a&nbsp;vertex,&nbsp;but&nbsp;it&nbsp;may&nbsp;not&nbsp;yet&nbsp;conform
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                099&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;to&nbsp;`vertex?`;&nbsp;it&nbsp;should&nbsp;also&nbsp;be&nbsp;scaled&nbsp;using&nbsp;the&nbsp;scale-vertex,&nbsp;if&nbsp;any.
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:x&nbsp;o)&nbsp;(let&nbsp;[c&nbsp;(v&#x2F;canonicalise&nbsp;o)]
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                101&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;scale-vertex
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(v&#x2F;vertex*&nbsp;c&nbsp;scale-vertex)
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;c))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;shouldn&#x27;t&nbsp;happen
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                105&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else&nbsp;o)))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                106&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                107&nbsp;&nbsp;(defn&nbsp;decode-binary-stl
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                108&nbsp;&nbsp;&nbsp;&nbsp;&quot;Parse&nbsp;a&nbsp;binary&nbsp;STL&nbsp;file&nbsp;from&nbsp;this&nbsp;`filename`&nbsp;and&nbsp;return&nbsp;an&nbsp;STL&nbsp;structure
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                109&nbsp;&nbsp;&nbsp;&nbsp;representing&nbsp;its&nbsp;contents.&nbsp;`map-kind`,&nbsp;if&nbsp;passed,&nbsp;must&nbsp;be&nbsp;a&nbsp;keyword
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                110&nbsp;&nbsp;&nbsp;&nbsp;or&nbsp;sequence&nbsp;of&nbsp;keywords&nbsp;indicating&nbsp;the&nbsp;semantic&nbsp;value&nbsp;represented&nbsp;by&nbsp;the&nbsp;`z`
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                111&nbsp;&nbsp;&nbsp;&nbsp;axis&nbsp;(defaults&nbsp;to&nbsp;`:height`).
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                112&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                113&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`superstructure`&nbsp;is&nbsp;supplied&nbsp;and&nbsp;is&nbsp;a&nbsp;map,&nbsp;the&nbsp;generated&nbsp;STL&nbsp;structure
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                114&nbsp;&nbsp;&nbsp;&nbsp;will&nbsp;be&nbsp;stored&nbsp;in&nbsp;that&nbsp;superstructure,&nbsp;which&nbsp;will&nbsp;be&nbsp;returned.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                115&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                116&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`scale-vertex`&nbsp;is&nbsp;supplied,&nbsp;it&nbsp;must&nbsp;be&nbsp;a&nbsp;three&nbsp;dimensional&nbsp;vertex&nbsp;(i.e.
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                117&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;`:z`&nbsp;key&nbsp;must&nbsp;have&nbsp;a&nbsp;numeric&nbsp;value)&nbsp;representing&nbsp;the&nbsp;amount&nbsp;by&nbsp;which
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                118&nbsp;&nbsp;&nbsp;&nbsp;each&nbsp;of&nbsp;the&nbsp;vertices&nbsp;read&nbsp;from&nbsp;the&nbsp;STL&nbsp;will&nbsp;be&nbsp;scaled.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                119&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                120&nbsp;&nbsp;&nbsp;&nbsp;It&nbsp;is&nbsp;an&nbsp;error,&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown,&nbsp;if&nbsp;`map-kind`&nbsp;is&nbsp;not&nbsp;a
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                121&nbsp;&nbsp;&nbsp;&nbsp;keyword&nbsp;or&nbsp;sequence&nbsp;of&nbsp;keywords.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                122&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                123&nbsp;&nbsp;&nbsp;&nbsp;**NOTE**&nbsp;that&nbsp;we&#x27;ve&nbsp;no&nbsp;way&nbsp;of&nbsp;verifying&nbsp;that&nbsp;the&nbsp;input&nbsp;file&nbsp;is&nbsp;binary&nbsp;STL
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                124&nbsp;&nbsp;&nbsp;&nbsp;data,&nbsp;if&nbsp;it&nbsp;is&nbsp;not&nbsp;this&nbsp;will&nbsp;run&nbsp;but&nbsp;will&nbsp;return&nbsp;garbage.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                125&nbsp;&nbsp;&nbsp;&nbsp;([filename]
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                126&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(decode-binary-stl&nbsp;filename&nbsp;:height))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                127&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;map-kind]
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                128&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                129&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(keyword?&nbsp;map-kind)
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                130&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 12 forms covered">
+                131&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(u&#x2F;truncate&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;keyword:&nbsp;&quot;&nbsp;(or&nbsp;map-kind&nbsp;&quot;nil&quot;))&nbsp;80))))
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                132&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(decode-binary-stl&nbsp;filename&nbsp;map-kind&nbsp;nil))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                133&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;mapkind&nbsp;superstucture]
+                </span><br/>
+<span class="not-covered" title="0 out of 10 forms covered">
+                134&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(decode-binary-stl&nbsp;filename&nbsp;mapkind&nbsp;superstucture&nbsp;(v&#x2F;vertex&nbsp;1&nbsp;1&nbsp;1)))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                135&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;map-kind&nbsp;superstructure&nbsp;scale-vertex]
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                136&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[in&nbsp;(io&#x2F;input-stream&nbsp;filename)
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                137&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;stl&nbsp;(canonicalise&nbsp;(b&#x2F;decode&nbsp;binary-stl&nbsp;in)&nbsp;map-kind&nbsp;scale-vertex)]
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                138&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                139&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;superstructure)
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                140&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(store&nbsp;stl&nbsp;superstructure)
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                141&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;stl))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                142&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                143&nbsp;&nbsp;(defn-&nbsp;vect-&gt;str&nbsp;[prefix&nbsp;v]
                 </span><br/>
 <span class="not-covered" title="0 out of 16 forms covered">
-                128&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;prefix&nbsp;&quot;&nbsp;&quot;&nbsp;(:x&nbsp;v)&nbsp;&quot;&nbsp;&quot;&nbsp;(:y&nbsp;v)&nbsp;&quot;&nbsp;&quot;&nbsp;(:z&nbsp;v)&nbsp;&quot;\n&quot;))
+                144&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;prefix&nbsp;&quot;&nbsp;&quot;&nbsp;(:x&nbsp;v)&nbsp;&quot;&nbsp;&quot;&nbsp;(:y&nbsp;v)&nbsp;&quot;&nbsp;&quot;&nbsp;(:z&nbsp;v)&nbsp;&quot;\n&quot;))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                129&nbsp;&nbsp;
+                145&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                130&nbsp;&nbsp;(defn-&nbsp;facet2str&nbsp;[tri]
+                146&nbsp;&nbsp;(defn-&nbsp;facet2str&nbsp;[tri]
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                131&nbsp;&nbsp;&nbsp;&nbsp;(str
+                147&nbsp;&nbsp;&nbsp;&nbsp;(str
                 </span><br/>
 <span class="not-covered" title="0 out of 6 forms covered">
-                132&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vect-&gt;str&nbsp;&quot;facet&nbsp;normal&quot;&nbsp;(:normal&nbsp;tri))
+                148&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vect-&gt;str&nbsp;&quot;facet&nbsp;normal&quot;&nbsp;(:normal&nbsp;tri))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                133&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;outer&nbsp;loop\n&quot;
+                149&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;outer&nbsp;loop\n&quot;
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                150&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                134&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(apply&nbsp;str
-                </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                135&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                151&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                136&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(vect-&gt;str&nbsp;&quot;vertex&quot;&nbsp;%)
+                152&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(vect-&gt;str&nbsp;&quot;vertex&quot;&nbsp;%)
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                137&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:vertices&nbsp;tri)))
+                153&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:vertices&nbsp;tri)))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                138&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;endloop\nendfacet\n&quot;))
+                154&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;endloop\nendfacet\n&quot;))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                139&nbsp;&nbsp;
+                155&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                140&nbsp;&nbsp;(defn&nbsp;stl-&gt;ascii
+                156&nbsp;&nbsp;(defn&nbsp;stl-&gt;ascii
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                141&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;as&nbsp;a&nbsp;string&nbsp;an&nbsp;ASCII&nbsp;rendering&nbsp;of&nbsp;the&nbsp;`stl`&nbsp;structure.&quot;
+                157&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;as&nbsp;a&nbsp;string&nbsp;an&nbsp;ASCII&nbsp;rendering&nbsp;of&nbsp;the&nbsp;`stl`&nbsp;structure.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                142&nbsp;&nbsp;&nbsp;&nbsp;([stl]
+                158&nbsp;&nbsp;&nbsp;&nbsp;([stl]
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                143&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl-&gt;ascii&nbsp;stl&nbsp;&quot;unknown&quot;))
+                159&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl-&gt;ascii&nbsp;stl&nbsp;&quot;unknown&quot;))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                144&nbsp;&nbsp;&nbsp;&nbsp;([stl&nbsp;solidname]
+                160&nbsp;&nbsp;&nbsp;&nbsp;([stl&nbsp;solidname]
                 </span><br/>
 <span class="not-covered" title="0 out of 6 forms covered">
-                145&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
+                161&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                146&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;solid&nbsp;&quot;
+                162&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;solid&nbsp;&quot;
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                147&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;solidname
+                163&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;solidname
                 </span><br/>
 <span class="not-covered" title="0 out of 5 forms covered">
-                148&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;trim&nbsp;(:header&nbsp;stl))
+                164&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;trim&nbsp;(:header&nbsp;stl))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                149&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;\n&quot;
+                165&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;\n&quot;
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                150&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(apply
-                </span><br/>
-<span class="not-covered" title="0 out of 1 forms covered">
-                151&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;str
+                166&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                152&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                167&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                153&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;facet2str
+                168&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;facet2str
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                154&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
+                169&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                155&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;endsolid&nbsp;&quot;
+                170&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;endsolid&nbsp;&quot;
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                156&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;solidname
+                171&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;solidname
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                157&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;\n&quot;)))
+                172&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;\n&quot;)))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                158&nbsp;&nbsp;
+                173&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                159&nbsp;&nbsp;(defn&nbsp;write-ascii-stl
+                174&nbsp;&nbsp;(defn&nbsp;write-ascii-stl
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                160&nbsp;&nbsp;&nbsp;&nbsp;&quot;Write&nbsp;an&nbsp;`stl`&nbsp;structure&nbsp;as&nbsp;read&nbsp;by&nbsp;`decode-binary-stl`&nbsp;to&nbsp;this
+                175&nbsp;&nbsp;&nbsp;&nbsp;&quot;Write&nbsp;an&nbsp;`stl`&nbsp;structure&nbsp;as&nbsp;read&nbsp;by&nbsp;`decode-binary-stl`&nbsp;to&nbsp;this
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                161&nbsp;&nbsp;&nbsp;&nbsp;`filename`&nbsp;as&nbsp;ASCII&nbsp;encoded&nbsp;STL.&quot;
+                176&nbsp;&nbsp;&nbsp;&nbsp;`filename`&nbsp;as&nbsp;ASCII&nbsp;encoded&nbsp;STL.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                162&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;stl]
+                177&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;stl]
                 </span><br/>
 <span class="not-covered" title="0 out of 5 forms covered">
-                163&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[b&nbsp;(fs&#x2F;base-name&nbsp;filename&nbsp;true)]
+                178&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[b&nbsp;(fs&#x2F;base-name&nbsp;filename&nbsp;true)]
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                164&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(write-ascii-stl
+                179&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(write-ascii-stl
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                165&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filename&nbsp;stl
+                180&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filename&nbsp;stl
                 </span><br/>
 <span class="not-covered" title="0 out of 15 forms covered">
-                166&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;b&nbsp;0&nbsp;(or&nbsp;(s&#x2F;index-of&nbsp;b&nbsp;&quot;.&quot;)&nbsp;(count&nbsp;b))))))
+                181&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;b&nbsp;0&nbsp;(or&nbsp;(s&#x2F;index-of&nbsp;b&nbsp;&quot;.&quot;)&nbsp;(count&nbsp;b))))))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                167&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;stl&nbsp;solidname]
+                182&nbsp;&nbsp;&nbsp;&nbsp;([filename&nbsp;stl&nbsp;solidname]
                 </span><br/>
 <span class="not-covered" title="0 out of 16 forms covered">
-                168&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;debug&nbsp;&quot;Solid&nbsp;name&nbsp;is&nbsp;&quot;&nbsp;solidname)
+                183&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;debug&nbsp;&quot;Solid&nbsp;name&nbsp;is&nbsp;&quot;&nbsp;solidname)
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                169&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(spit
+                184&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(spit
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                170&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filename
+                185&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;filename
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                171&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl-&gt;ascii&nbsp;stl&nbsp;solidname))))
+                186&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl-&gt;ascii&nbsp;stl&nbsp;solidname))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                172&nbsp;&nbsp;
+                187&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                173&nbsp;&nbsp;(defn&nbsp;binary-stl-to-ascii
+                188&nbsp;&nbsp;(defn&nbsp;binary-stl-to-ascii
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                174&nbsp;&nbsp;&nbsp;&nbsp;&quot;Convert&nbsp;the&nbsp;binary&nbsp;STL&nbsp;file&nbsp;indicated&nbsp;by&nbsp;`in-filename`,&nbsp;and&nbsp;write&nbsp;it&nbsp;to
+                189&nbsp;&nbsp;&nbsp;&nbsp;&quot;Convert&nbsp;the&nbsp;binary&nbsp;STL&nbsp;file&nbsp;indicated&nbsp;by&nbsp;`in-filename`,&nbsp;and&nbsp;write&nbsp;it&nbsp;to
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                175&nbsp;&nbsp;&nbsp;&nbsp;`out-filename`,&nbsp;if&nbsp;specified;&nbsp;otherwise,&nbsp;to&nbsp;a&nbsp;file&nbsp;with&nbsp;the&nbsp;same&nbsp;basename
+                190&nbsp;&nbsp;&nbsp;&nbsp;`out-filename`,&nbsp;if&nbsp;specified;&nbsp;otherwise,&nbsp;to&nbsp;a&nbsp;file&nbsp;with&nbsp;the&nbsp;same&nbsp;basename
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                176&nbsp;&nbsp;&nbsp;&nbsp;as&nbsp;`in-filename`&nbsp;but&nbsp;the&nbsp;extension&nbsp;`.ascii.stl`.&quot;
+                191&nbsp;&nbsp;&nbsp;&nbsp;as&nbsp;`in-filename`&nbsp;but&nbsp;the&nbsp;extension&nbsp;`.ascii.stl`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                177&nbsp;&nbsp;&nbsp;&nbsp;([in-filename]
+                192&nbsp;&nbsp;&nbsp;&nbsp;([in-filename]
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                178&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[[_&nbsp;ext]&nbsp;(fs&#x2F;split-ext&nbsp;in-filename)]
+                193&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[[_&nbsp;ext]&nbsp;(fs&#x2F;split-ext&nbsp;in-filename)]
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                179&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(binary-stl-to-ascii
+                194&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(binary-stl-to-ascii
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                180&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;in-filename
+                195&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;in-filename
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                181&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
+                196&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                182&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs
+                197&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                183&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;in-filename
+                198&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;in-filename
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                184&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0
+                199&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0
                 </span><br/>
 <span class="not-covered" title="0 out of 5 forms covered">
-                185&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or
+                200&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                186&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;last-index-of&nbsp;in-filename&nbsp;&quot;.&quot;)
+                201&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;last-index-of&nbsp;in-filename&nbsp;&quot;.&quot;)
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                187&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(count&nbsp;in-filename)))
+                202&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(count&nbsp;in-filename)))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                188&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;.ascii&quot;
+                203&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;.ascii&quot;
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                189&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ext))))
+                204&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;ext))))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                190&nbsp;&nbsp;&nbsp;&nbsp;([in-filename&nbsp;out-filename]
+                205&nbsp;&nbsp;&nbsp;&nbsp;([in-filename&nbsp;out-filename]
                 </span><br/>
 <span class="not-covered" title="0 out of 6 forms covered">
-                191&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(write-ascii-stl&nbsp;out-filename&nbsp;(decode-binary-stl&nbsp;in-filename))))
+                206&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(write-ascii-stl&nbsp;out-filename&nbsp;(decode-binary-stl&nbsp;in-filename))))
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/superstructure.clj.html b/docs/cloverage/walkmap/superstructure.clj.html
index e2963e8..a83ad6d 100644
--- a/docs/cloverage/walkmap/superstructure.clj.html
+++ b/docs/cloverage/walkmap/superstructure.clj.html
@@ -11,253 +11,547 @@
                 002&nbsp;&nbsp;&nbsp;&nbsp;&quot;single&nbsp;indexing&nbsp;structure&nbsp;for&nbsp;walkmap&nbsp;objects&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                003&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[walkmap.path&nbsp;:as&nbsp;p]
+                003&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.walk&nbsp;:refer&nbsp;[postwalk]]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                004&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:as&nbsp;q]
+                004&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                005&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.stl&nbsp;:as&nbsp;s]
+                005&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.path&nbsp;:as&nbsp;p]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:as&nbsp;u]
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:as&nbsp;q]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:as&nbsp;v]))
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:as&nbsp;u]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:as&nbsp;v]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                008&nbsp;&nbsp;
+                009&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                009&nbsp;&nbsp;;;&nbsp;TODO:&nbsp;Think&nbsp;about&nbsp;reification&#x2F;dereification.&nbsp;How&nbsp;can&nbsp;we&nbsp;cull&nbsp;a&nbsp;polygon,&nbsp;if
+                010&nbsp;&nbsp;;;&nbsp;TODO:&nbsp;Think&nbsp;about&nbsp;reification&#x2F;dereification.&nbsp;How&nbsp;can&nbsp;we&nbsp;cull&nbsp;a&nbsp;polygon,&nbsp;if
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                010&nbsp;&nbsp;;;&nbsp;some&nbsp;vertices&nbsp;still&nbsp;index&nbsp;it?&nbsp;I&nbsp;*think*&nbsp;that&nbsp;what&#x27;s&nbsp;needed&nbsp;is&nbsp;that&nbsp;when
+                011&nbsp;&nbsp;;;&nbsp;some&nbsp;vertices&nbsp;still&nbsp;index&nbsp;it?&nbsp;I&nbsp;*think*&nbsp;that&nbsp;what&#x27;s&nbsp;needed&nbsp;is&nbsp;that&nbsp;when
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;;;&nbsp;we&nbsp;store&nbsp;something&nbsp;in&nbsp;the&nbsp;superstructure,&nbsp;we&nbsp;replace&nbsp;all&nbsp;its&nbsp;vertices&nbsp;(and
+                012&nbsp;&nbsp;;;&nbsp;we&nbsp;store&nbsp;something&nbsp;in&nbsp;the&nbsp;superstructure,&nbsp;we&nbsp;replace&nbsp;all&nbsp;its&nbsp;vertices&nbsp;(and
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                012&nbsp;&nbsp;;;&nbsp;other&nbsp;dependent&nbsp;structures,&nbsp;if&nbsp;any&nbsp;with&nbsp;their&nbsp;ids&nbsp;-&nbsp;as&nbsp;well&nbsp;as,&nbsp;obviously,
+                013&nbsp;&nbsp;;;&nbsp;other&nbsp;dependent&nbsp;structures,&nbsp;if&nbsp;any&nbsp;with&nbsp;their&nbsp;ids&nbsp;-&nbsp;as&nbsp;well&nbsp;as,&nbsp;obviously,
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                013&nbsp;&nbsp;;;&nbsp;adding&#x2F;merging&nbsp;those&nbsp;vertices&#x2F;dependent&nbsp;structures&nbsp;into&nbsp;the&nbsp;superstructure
+                014&nbsp;&nbsp;;;&nbsp;adding&#x2F;merging&nbsp;those&nbsp;vertices&#x2F;dependent&nbsp;structures&nbsp;into&nbsp;the&nbsp;superstructure
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                014&nbsp;&nbsp;;;&nbsp;as&nbsp;first&nbsp;class&nbsp;objects&nbsp;in&nbsp;themselves.&nbsp;That&nbsp;means,&nbsp;for&nbsp;each&nbsp;identified&nbsp;thing,
+                015&nbsp;&nbsp;;;&nbsp;as&nbsp;first&nbsp;class&nbsp;objects&nbsp;in&nbsp;themselves.&nbsp;That&nbsp;means,&nbsp;for&nbsp;each&nbsp;identified&nbsp;thing,
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                015&nbsp;&nbsp;;;&nbsp;the&nbsp;superstructure&nbsp;only&nbsp;contains&nbsp;one&nbsp;copy&nbsp;of&nbsp;it.
+                016&nbsp;&nbsp;;;&nbsp;the&nbsp;superstructure&nbsp;only&nbsp;contains&nbsp;one&nbsp;copy&nbsp;of&nbsp;it.
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                016&nbsp;&nbsp;;;
+                017&nbsp;&nbsp;;;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                017&nbsp;&nbsp;;;&nbsp;The&nbsp;question&nbsp;then&nbsp;is,&nbsp;when&nbsp;we&nbsp;want&nbsp;to&nbsp;do&nbsp;things&nbsp;with&nbsp;those&nbsp;objects,&nbsp;do&nbsp;we
+                018&nbsp;&nbsp;;;&nbsp;The&nbsp;question&nbsp;then&nbsp;is,&nbsp;when&nbsp;we&nbsp;want&nbsp;to&nbsp;do&nbsp;things&nbsp;with&nbsp;those&nbsp;objects,&nbsp;do&nbsp;we
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                018&nbsp;&nbsp;;;&nbsp;exteract&nbsp;a&nbsp;copy&nbsp;with&nbsp;its&nbsp;dependent&nbsp;structures&nbsp;fixed&nbsp;back&nbsp;up&nbsp;(reification),
+                019&nbsp;&nbsp;;;&nbsp;exteract&nbsp;a&nbsp;copy&nbsp;with&nbsp;its&nbsp;dependent&nbsp;structures&nbsp;fixed&nbsp;back&nbsp;up&nbsp;(reification),
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                019&nbsp;&nbsp;;;&nbsp;or&nbsp;do&nbsp;we&nbsp;indirect&nbsp;through&nbsp;the&nbsp;superstructure&nbsp;every&nbsp;time&nbsp;we&nbsp;want&nbsp;to&nbsp;access
+                020&nbsp;&nbsp;;;&nbsp;or&nbsp;do&nbsp;we&nbsp;indirect&nbsp;through&nbsp;the&nbsp;superstructure&nbsp;every&nbsp;time&nbsp;we&nbsp;want&nbsp;to&nbsp;access
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                020&nbsp;&nbsp;;;&nbsp;them?&nbsp;In&nbsp;a&nbsp;sense,&nbsp;the&nbsp;copy&nbsp;in&nbsp;the&nbsp;superstructure&nbsp;is&nbsp;the&nbsp;&#x27;one&nbsp;true&nbsp;copy&#x27;,
+                021&nbsp;&nbsp;;;&nbsp;them?&nbsp;In&nbsp;a&nbsp;sense,&nbsp;the&nbsp;copy&nbsp;in&nbsp;the&nbsp;superstructure&nbsp;is&nbsp;the&nbsp;&#x27;one&nbsp;true&nbsp;copy&#x27;,
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                021&nbsp;&nbsp;;;&nbsp;but&nbsp;it&nbsp;may&nbsp;become&nbsp;very&nbsp;difficult&nbsp;then&nbsp;to&nbsp;have&nbsp;one&nbsp;true&nbsp;copy&nbsp;of&nbsp;the
+                022&nbsp;&nbsp;;;&nbsp;but&nbsp;it&nbsp;may&nbsp;become&nbsp;very&nbsp;difficult&nbsp;then&nbsp;to&nbsp;have&nbsp;one&nbsp;true&nbsp;copy&nbsp;of&nbsp;the
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                022&nbsp;&nbsp;;;&nbsp;superstructure&nbsp;-&nbsp;unless&nbsp;we&nbsp;replace&nbsp;the&nbsp;superstructure&nbsp;altogether&nbsp;with&nbsp;a
+                023&nbsp;&nbsp;;;&nbsp;superstructure&nbsp;-&nbsp;unless&nbsp;we&nbsp;replace&nbsp;the&nbsp;superstructure&nbsp;altogether&nbsp;with&nbsp;a
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                023&nbsp;&nbsp;;;&nbsp;database,&nbsp;which&nbsp;may&nbsp;be&nbsp;the&nbsp;Right&nbsp;Thing&nbsp;To&nbsp;Do.
+                024&nbsp;&nbsp;;;&nbsp;database,&nbsp;which&nbsp;may&nbsp;be&nbsp;the&nbsp;Right&nbsp;Thing&nbsp;To&nbsp;Do.
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                024&nbsp;&nbsp;
+                025&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                026&nbsp;&nbsp;(def&nbsp;vertex-index&nbsp;::vertex-index)
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                027&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                025&nbsp;&nbsp;(defn&nbsp;index-vertex
+                028&nbsp;&nbsp;(defn&nbsp;vertices
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                026&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;superstructure&nbsp;like&nbsp;`s`&nbsp;in&nbsp;which&nbsp;object&nbsp;`o`&nbsp;is&nbsp;indexed&nbsp;by&nbsp;vertex
+                029&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;an&nbsp;object&nbsp;with&nbsp;vertices,&nbsp;return&nbsp;those&nbsp;vertices,&nbsp;else&nbsp;nil.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                027&nbsp;&nbsp;&nbsp;&nbsp;`v`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;may&nbsp;be&nbsp;thrown)&nbsp;if
+                030&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                028&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                029&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`s`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                030&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                031&nbsp;&nbsp;&nbsp;&nbsp;3.&nbsp;`o`&nbsp;does&nbsp;not&nbsp;have&nbsp;a&nbsp;value&nbsp;for&nbsp;the&nbsp;key&nbsp;`:id`;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                032&nbsp;&nbsp;&nbsp;&nbsp;4.&nbsp;`v`&nbsp;is&nbsp;not&nbsp;a&nbsp;vertex.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                033&nbsp;&nbsp;&nbsp;&nbsp;[s&nbsp;o&nbsp;v]
+<span class="not-covered" title="0 out of 4 forms covered">
+                031&nbsp;&nbsp;&nbsp;&nbsp;(cond
                 </span><br/>
 <span class="not-covered" title="0 out of 6 forms covered">
-                034&nbsp;&nbsp;&nbsp;&nbsp;(if-not&nbsp;(v&#x2F;vertex?&nbsp;o)
+                032&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(v&#x2F;vertex?&nbsp;o)&nbsp;(list&nbsp;o)
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                033&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(q&#x2F;polygon?&nbsp;o)&nbsp;(:vertices&nbsp;o)
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                034&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(p&#x2F;path?&nbsp;o)&nbsp;(:vertices&nbsp;o)))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                035&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                036&nbsp;&nbsp;(defn&nbsp;index-vertex
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                037&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;superstructure&nbsp;like&nbsp;`s`&nbsp;in&nbsp;which&nbsp;object&nbsp;`o`&nbsp;is&nbsp;indexed&nbsp;by&nbsp;vertex
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                038&nbsp;&nbsp;&nbsp;&nbsp;`v`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;may&nbsp;be&nbsp;thrown)&nbsp;if
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                039&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                040&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`s`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                041&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                042&nbsp;&nbsp;&nbsp;&nbsp;3.&nbsp;`o`&nbsp;does&nbsp;not&nbsp;have&nbsp;a&nbsp;value&nbsp;for&nbsp;the&nbsp;key&nbsp;`:walkmap.id&#x2F;id`;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                043&nbsp;&nbsp;&nbsp;&nbsp;4.&nbsp;`v`&nbsp;is&nbsp;not&nbsp;a&nbsp;vertex.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                044&nbsp;&nbsp;&nbsp;&nbsp;[s&nbsp;o&nbsp;v]
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                045&nbsp;&nbsp;&nbsp;&nbsp;(if-not&nbsp;(v&#x2F;vertex?&nbsp;o)
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(v&#x2F;vertex?&nbsp;v)
+                </span><br/>
+<span class="covered" title="9 out of 9 forms covered">
+                048&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[vi&nbsp;(or&nbsp;(::vertex-index&nbsp;s)&nbsp;{})
+                </span><br/>
+<span class="partial" title="9 out of 10 forms covered">
+                049&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;current&nbsp;(or&nbsp;(vi&nbsp;(:walkmap.id&#x2F;id&nbsp;v))&nbsp;{})]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                050&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;deep-merge&nbsp;doesn&#x27;t&nbsp;merge&nbsp;sets,&nbsp;only&nbsp;maps;&nbsp;so&nbsp;at&nbsp;this
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                051&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;stage&nbsp;we&nbsp;need&nbsp;to&nbsp;build&nbsp;a&nbsp;map.
+                </span><br/>
+<span class="covered" title="15 out of 15 forms covered">
+                052&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;vi&nbsp;(:walkmap.id&#x2F;id&nbsp;v)&nbsp;(assoc&nbsp;current&nbsp;(:walkmap.id&#x2F;id&nbsp;o)&nbsp;(:walkmap.id&#x2F;id&nbsp;v))))
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                035&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(:id&nbsp;o)
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(v&#x2F;vertex?&nbsp;v)
+                053&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;v)))
                 </span><br/>
 <span class="not-covered" title="0 out of 9 forms covered">
-                037&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[vi&nbsp;(or&nbsp;(:vertex-index&nbsp;s)&nbsp;{})
-                </span><br/>
-<span class="not-covered" title="0 out of 10 forms covered">
-                038&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;current&nbsp;(or&nbsp;(vi&nbsp;(:id&nbsp;v))&nbsp;{})]
+                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;(u&#x2F;truncate&nbsp;(str&nbsp;&quot;No&nbsp;`:walkmap.id&#x2F;id`&nbsp;value:&nbsp;&quot;&nbsp;o)&nbsp;80))))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                039&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;deep-merge&nbsp;doesn&#x27;t&nbsp;merge&nbsp;sets,&nbsp;only&nbsp;maps;&nbsp;so&nbsp;at&nbsp;this
+                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;it&nbsp;shouldn&#x27;t&nbsp;actually&nbsp;be&nbsp;an&nbsp;error&nbsp;to&nbsp;try&nbsp;to&nbsp;index&nbsp;a&nbsp;vertex,&nbsp;but&nbsp;it
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                040&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;stage&nbsp;we&nbsp;need&nbsp;to&nbsp;build&nbsp;a&nbsp;map.
-                </span><br/>
-<span class="not-covered" title="0 out of 15 forms covered">
-                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;vi&nbsp;(:id&nbsp;v)&nbsp;(assoc&nbsp;current&nbsp;(:id&nbsp;o)&nbsp;(:id&nbsp;v))))
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;v)))
-                </span><br/>
-<span class="not-covered" title="0 out of 10 forms covered">
-                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;(subs&nbsp;(str&nbsp;&quot;No&nbsp;`:id`&nbsp;value:&nbsp;&quot;&nbsp;o)&nbsp;0&nbsp;80))))
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;it&nbsp;shouldn&#x27;t&nbsp;actually&nbsp;be&nbsp;an&nbsp;error&nbsp;to&nbsp;try&nbsp;to&nbsp;index&nbsp;a&nbsp;vertex,&nbsp;but&nbsp;it
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;also&nbsp;isn&#x27;t&nbsp;useful&nbsp;to&nbsp;do&nbsp;so,&nbsp;so&nbsp;I&#x27;d&nbsp;be&nbsp;inclined&nbsp;to&nbsp;ignore&nbsp;it.
+                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;also&nbsp;isn&#x27;t&nbsp;useful&nbsp;to&nbsp;do&nbsp;so,&nbsp;so&nbsp;I&#x27;d&nbsp;be&nbsp;inclined&nbsp;to&nbsp;ignore&nbsp;it.
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:vertex-index&nbsp;s)))
+                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(::vertex-index&nbsp;s)))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                047&nbsp;&nbsp;
+                058&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                048&nbsp;&nbsp;(defn&nbsp;index-vertices
+                059&nbsp;&nbsp;(defn&nbsp;index-vertices
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                049&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;superstructure&nbsp;like&nbsp;`s`&nbsp;in&nbsp;which&nbsp;object&nbsp;`o`&nbsp;is&nbsp;indexed&nbsp;by&nbsp;its
+                060&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;superstructure&nbsp;like&nbsp;`s`&nbsp;in&nbsp;which&nbsp;object&nbsp;`o`&nbsp;is&nbsp;indexed&nbsp;by&nbsp;its
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                050&nbsp;&nbsp;&nbsp;&nbsp;vertices.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;may&nbsp;be&nbsp;thrown)&nbsp;if
+                061&nbsp;&nbsp;&nbsp;&nbsp;vertices.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;may&nbsp;be&nbsp;thrown)&nbsp;if
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                051&nbsp;&nbsp;
+                062&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                052&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`s`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
+                063&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`s`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                053&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
+                064&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                054&nbsp;&nbsp;&nbsp;&nbsp;3.&nbsp;`o`&nbsp;does&nbsp;not&nbsp;have&nbsp;a&nbsp;value&nbsp;for&nbsp;the&nbsp;key&nbsp;`:id`.&quot;
+                065&nbsp;&nbsp;&nbsp;&nbsp;3.&nbsp;`o`&nbsp;does&nbsp;not&nbsp;have&nbsp;a&nbsp;value&nbsp;for&nbsp;the&nbsp;key&nbsp;`:walkmap.id&#x2F;id`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                055&nbsp;&nbsp;&nbsp;&nbsp;[s&nbsp;o]
+                066&nbsp;&nbsp;&nbsp;&nbsp;[s&nbsp;o]
                 </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                056&nbsp;&nbsp;&nbsp;&nbsp;(assoc
+<span class="covered" title="2 out of 2 forms covered">
+                067&nbsp;&nbsp;&nbsp;&nbsp;(u&#x2F;deep-merge
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;s
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                069&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{::vertex-index
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                070&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                071&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;u&#x2F;deep-merge
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{}
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                073&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                </span><br/>
+<span class="covered" title="5 out of 5 forms covered">
+                074&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(index-vertex&nbsp;s&nbsp;o&nbsp;%)
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:vertices&nbsp;o)))}))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                076&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                077&nbsp;&nbsp;(defn&nbsp;in-retrieve
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                078&nbsp;&nbsp;&nbsp;&nbsp;&quot;Internal&nbsp;guts&nbsp;of&nbsp;`retrieve`,&nbsp;q.v.&nbsp;`x`&nbsp;can&nbsp;be&nbsp;anything;&nbsp;`s`&nbsp;must&nbsp;be&nbsp;a
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                079&nbsp;&nbsp;&nbsp;&nbsp;walkmap&nbsp;superstructure.&nbsp;TODO:&nbsp;recursive,&nbsp;quite&nbsp;likely&nbsp;to&nbsp;blow&nbsp;the&nbsp;fragile
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                080&nbsp;&nbsp;&nbsp;&nbsp;Clojure&nbsp;stack.&nbsp;Probably&nbsp;better&nbsp;to&nbsp;do&nbsp;this&nbsp;with&nbsp;`walk`,&nbsp;but&nbsp;I&nbsp;don&#x27;t&nbsp;yet
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                081&nbsp;&nbsp;&nbsp;&nbsp;understand&nbsp;that.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                082&nbsp;&nbsp;&nbsp;&nbsp;[x&nbsp;s]
+                </span><br/>
+<span class="covered" title="5 out of 5 forms covered">
+                083&nbsp;&nbsp;&nbsp;&nbsp;(cond
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&#x27;s&nbsp;a&nbsp;keyword&nbsp;identifying&nbsp;something&nbsp;in&nbsp;s,&nbsp;retrieve&nbsp;that&nbsp;something.
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(keyword?&nbsp;x)&nbsp;(if&nbsp;(s&nbsp;x)
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                086&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(in-retrieve&nbsp;(s&nbsp;x)&nbsp;s)
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                087&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;x)
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                088&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&#x27;s&nbsp;a&nbsp;map,&nbsp;for&nbsp;every&nbsp;key&nbsp;which&nbsp;is&nbsp;not&nbsp;`:walkmap.id&#x2F;id`,&nbsp;recurse.
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                089&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;x)&nbsp;(let&nbsp;[v&nbsp;(reduce
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                090&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(fn&nbsp;[m&nbsp;k]
+                </span><br/>
+<span class="covered" title="10 out of 10 forms covered">
+                091&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;m&nbsp;k&nbsp;(in-retrieve&nbsp;(x&nbsp;k)&nbsp;s)))
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                092&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{}
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                093&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(keys&nbsp;(dissoc&nbsp;x&nbsp;:walkmap.id&#x2F;id)))
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                094&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;id&nbsp;(:walkmap.id&#x2F;id&nbsp;x)]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                095&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;if&nbsp;it&nbsp;has&nbsp;an&nbsp;id,&nbsp;bind&nbsp;it&nbsp;to&nbsp;that&nbsp;id&nbsp;in&nbsp;the&nbsp;returned&nbsp;value.
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                096&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;id
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                097&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                098&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;v
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                099&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:walkmap.id&#x2F;id
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;x))
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;s
+                101&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;v))
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(set?&nbsp;x)&nbsp;x&nbsp;;;&nbsp;TODO:&nbsp;should&nbsp;I&nbsp;search&nbsp;in&nbsp;sets&nbsp;for&nbsp;objects&nbsp;when&nbsp;storing?
+                </span><br/>
+<span class="covered" title="11 out of 11 forms covered">
+                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(coll?&nbsp;x)&nbsp;(map&nbsp;#(in-retrieve&nbsp;%&nbsp;s)&nbsp;x)
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else&nbsp;x))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                105&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                106&nbsp;&nbsp;(defn&nbsp;retrieve
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:vertex-index
+                107&nbsp;&nbsp;&nbsp;&nbsp;&quot;Retrieve&nbsp;the&nbsp;canonical&nbsp;representation&nbsp;of&nbsp;the&nbsp;object&nbsp;with&nbsp;this&nbsp;`id`&nbsp;from&nbsp;the
                 </span><br/>
-<span class="not-covered" title="0 out of 2 forms covered">
-                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(reduce
+<span class="not-tracked" title="0 out of 0 forms covered">
+                108&nbsp;&nbsp;&nbsp;&nbsp;superstructure&nbsp;`s`.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                109&nbsp;&nbsp;&nbsp;&nbsp;[id&nbsp;s]
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                110&nbsp;&nbsp;&nbsp;&nbsp;(in-retrieve&nbsp;(id&nbsp;s)&nbsp;s))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                111&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                112&nbsp;&nbsp;(defn&nbsp;in-store-find-objects
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                113&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;id&nbsp;-&gt;&nbsp;object&nbsp;map&nbsp;of&nbsp;every&nbsp;object&nbsp;within&nbsp;`o`.&nbsp;Internal&nbsp;to
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                114&nbsp;&nbsp;&nbsp;&nbsp;`in-store`,&nbsp;q.v.&nbsp;Use&nbsp;at&nbsp;your&nbsp;own&nbsp;peril.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                115&nbsp;&nbsp;&nbsp;&nbsp;([o]
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                116&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(in-store-find-objects&nbsp;o&nbsp;{}))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                117&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;s]
+                </span><br/>
+<span class="covered" title="16 out of 16 forms covered">
+                118&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;debug&nbsp;&quot;Finding&nbsp;objects&nbsp;in:&quot;&nbsp;o)
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                119&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                120&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(set?&nbsp;o)&nbsp;s&nbsp;;;&nbsp;TODO:&nbsp;should&nbsp;I&nbsp;search&nbsp;in&nbsp;sets&nbsp;for&nbsp;objects&nbsp;when&nbsp;storing?
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                121&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)&nbsp;(if&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                122&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                123&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(in-store-find-objects&nbsp;(vals&nbsp;o)&nbsp;s)
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                124&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                125&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;o)
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                126&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(in-store-find-objects&nbsp;(vals&nbsp;o)&nbsp;s))
+                </span><br/>
+<span class="covered" title="15 out of 15 forms covered">
+                127&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(coll?&nbsp;o)&nbsp;(reduce&nbsp;merge&nbsp;s&nbsp;(map&nbsp;#(in-store-find-objects&nbsp;%&nbsp;s)&nbsp;o))
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                128&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else&nbsp;s)))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                129&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                130&nbsp;&nbsp;(defn&nbsp;in-store-replace-with-keys
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                131&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;copy&nbsp;of&nbsp;`o`&nbsp;in&nbsp;which&nbsp;each&nbsp;reified&nbsp;walkmap&nbsp;object&nbsp;within&nbsp;`o`&nbsp;has
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                132&nbsp;&nbsp;&nbsp;&nbsp;been&nbsp;replaced&nbsp;with&nbsp;the&nbsp;`:walkmap.id&#x2F;id`&nbsp;of&nbsp;that&nbsp;object.&nbsp;Internal&nbsp;to
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                133&nbsp;&nbsp;&nbsp;&nbsp;`in-store`,&nbsp;q.v.&nbsp;Use&nbsp;at&nbsp;your&nbsp;own&nbsp;peril.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                134&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                135&nbsp;&nbsp;&nbsp;&nbsp;(assoc
+                </span><br/>
+<span class="covered" title="15 out of 15 forms covered">
+                136&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(postwalk&nbsp;#(or&nbsp;(:walkmap.id&#x2F;id&nbsp;%)&nbsp;%)&nbsp;(dissoc&nbsp;o&nbsp;:walkmap.id&#x2F;id))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                137&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:walkmap.id&#x2F;id
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                138&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;o)))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                139&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                140&nbsp;&nbsp;;;&nbsp;(in-store-replace-with-keys&nbsp;(p&#x2F;path&nbsp;(v&#x2F;vertex&nbsp;0&nbsp;0&nbsp;0)&nbsp;(v&#x2F;vertex&nbsp;0&nbsp;1&nbsp;2)&nbsp;(v&#x2F;vertex&nbsp;3&nbsp;3&nbsp;3)))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                141&nbsp;&nbsp;;;&nbsp;(in-store-find-objects&nbsp;(p&#x2F;path&nbsp;(v&#x2F;vertex&nbsp;0&nbsp;0&nbsp;0)&nbsp;(v&#x2F;vertex&nbsp;0&nbsp;1&nbsp;2)&nbsp;(v&#x2F;vertex&nbsp;3&nbsp;3&nbsp;3)))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                142&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                143&nbsp;&nbsp;(defn&nbsp;store
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                144&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;superstructure&nbsp;like&nbsp;`s`&nbsp;with&nbsp;object&nbsp;`o`&nbsp;added.&nbsp;If&nbsp;only&nbsp;one
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                145&nbsp;&nbsp;&nbsp;&nbsp;argument&nbsp;is&nbsp;supplied&nbsp;it&nbsp;will&nbsp;be&nbsp;assumed&nbsp;to&nbsp;represent&nbsp;`o`&nbsp;and&nbsp;a&nbsp;new
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                146&nbsp;&nbsp;&nbsp;&nbsp;superstructure&nbsp;will&nbsp;be&nbsp;returned.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                147&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                148&nbsp;&nbsp;&nbsp;&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;may&nbsp;be&nbsp;thrown)&nbsp;if
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                149&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                150&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`s`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                151&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;recognisable&nbsp;walkmap&nbsp;object&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                152&nbsp;&nbsp;&nbsp;&nbsp;([o]
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                153&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(store&nbsp;o&nbsp;{}))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                154&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;s]
+                </span><br/>
+<span class="partial" title="5 out of 6 forms covered">
+                155&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;u&#x2F;deep-merge
+                156&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                157&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                158&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;walkmap&nbsp;object:&nbsp;no&nbsp;value&nbsp;for&nbsp;`:walkmap.id&#x2F;id`:&nbsp;&quot;
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                159&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(u&#x2F;kind-type&nbsp;o)))))
+                </span><br/>
+<span class="partial" title="5 out of 6 forms covered">
+                160&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(map?&nbsp;s)
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                161&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                162&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                163&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Superstructure&nbsp;must&nbsp;be&nbsp;a&nbsp;map:&nbsp;&quot;&nbsp;(u&#x2F;kind-type&nbsp;s)))))
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                164&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc
+                </span><br/>
+<span class="covered" title="10 out of 10 forms covered">
+                165&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(u&#x2F;deep-merge&nbsp;s&nbsp;(in-store-find-objects&nbsp;o)&nbsp;(index-vertices&nbsp;s&nbsp;o))
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                166&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                167&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(in-store-replace-with-keys&nbsp;o))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                168&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                169&nbsp;&nbsp;(defn&nbsp;search-vertices
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                170&nbsp;&nbsp;&nbsp;&nbsp;&quot;Search&nbsp;superstructure&nbsp;`s`&nbsp;for&nbsp;vertices&nbsp;within&nbsp;the&nbsp;box&nbsp;defined&nbsp;by&nbsp;vertices
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                171&nbsp;&nbsp;&nbsp;&nbsp;`minv`&nbsp;and&nbsp;`maxv`.&nbsp;Every&nbsp;coordinate&nbsp;in&nbsp;`minv`&nbsp;must&nbsp;have&nbsp;a&nbsp;lower&nbsp;value&nbsp;than
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                172&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;equivalent&nbsp;coordinate&nbsp;in&nbsp;`maxv`.&nbsp;If&nbsp;`d2?`&nbsp;is&nbsp;supplied&nbsp;and&nbsp;not&nbsp;false,
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                173&nbsp;&nbsp;&nbsp;&nbsp;search&nbsp;only&nbsp;in&nbsp;the&nbsp;x,y&nbsp;projection.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                174&nbsp;&nbsp;&nbsp;&nbsp;([s&nbsp;minv&nbsp;maxv]
+                </span><br/>
+<span class="not-covered" title="0 out of 6 forms covered">
+                175&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(search-vertices&nbsp;s&nbsp;minv&nbsp;maxv&nbsp;false))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                176&nbsp;&nbsp;&nbsp;&nbsp;([s&nbsp;minv&nbsp;maxv&nbsp;d2?]
+                </span><br/>
+<span class="not-covered" title="0 out of 9 forms covered">
+                177&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[minv&#x27;&nbsp;(if&nbsp;d2?&nbsp;(assoc&nbsp;minv&nbsp;:z&nbsp;Double&#x2F;NEGATIVE_INFINITY)&nbsp;minv)
+                </span><br/>
+<span class="not-covered" title="0 out of 8 forms covered">
+                178&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;maxv&#x27;&nbsp;(if&nbsp;d2?&nbsp;(assoc&nbsp;maxv&nbsp;:z&nbsp;Double&#x2F;POSITIVE_INFINITY)&nbsp;maxv)]
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                179&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(filter
                 </span><br/>
 <span class="not-covered" title="0 out of 5 forms covered">
-                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(index-vertex&nbsp;s&nbsp;o&nbsp;%)
+                180&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(v&#x2F;within-box?&nbsp;%&nbsp;minv&nbsp;maxv)
                 </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(u&#x2F;vertices&nbsp;o)))))
+<span class="not-covered" title="0 out of 12 forms covered">
+                181&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(filter&nbsp;#(=&nbsp;(:kind&nbsp;%)&nbsp;:vertex)&nbsp;(vals&nbsp;s))))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                064&nbsp;&nbsp;
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                065&nbsp;&nbsp;(defn&nbsp;add-to-superstructure
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                066&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;superstructure&nbsp;like&nbsp;`s`&nbsp;with&nbsp;object&nbsp;`o`&nbsp;added.&nbsp;If&nbsp;`o`&nbsp;is&nbsp;a&nbsp;collection,
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                067&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;a&nbsp;superstructure&nbsp;like&nbsp;`s`&nbsp;with&nbsp;each&nbsp;element&nbsp;of&nbsp;`o`&nbsp;added.&nbsp;If&nbsp;only&nbsp;one
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                068&nbsp;&nbsp;&nbsp;&nbsp;argument&nbsp;is&nbsp;supplied&nbsp;it&nbsp;will&nbsp;be&nbsp;assumed&nbsp;to&nbsp;represent&nbsp;`o`&nbsp;and&nbsp;a&nbsp;new
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                069&nbsp;&nbsp;&nbsp;&nbsp;superstructure&nbsp;will&nbsp;be&nbsp;returned.
+                182&nbsp;&nbsp;
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                070&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                071&nbsp;&nbsp;&nbsp;&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;may&nbsp;be&nbsp;thrown)&nbsp;if
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                072&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                073&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`s`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                074&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;map,&nbsp;or&nbsp;a&nbsp;sequence&nbsp;of&nbsp;maps.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                075&nbsp;&nbsp;&nbsp;&nbsp;([o]
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(add-to-superstructure&nbsp;{}&nbsp;o))
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                077&nbsp;&nbsp;&nbsp;&nbsp;([s&nbsp;o]
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                078&nbsp;&nbsp;&nbsp;&nbsp;(cond
-                </span><br/>
-<span class="not-covered" title="0 out of 18 forms covered">
-                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)&nbsp;(let&nbsp;[o&#x27;&nbsp;(if&nbsp;(:id&nbsp;o)&nbsp;o&nbsp;(assoc&nbsp;o&nbsp;:id&nbsp;(keyword&nbsp;(gensym&nbsp;&quot;obj&quot;))))]
-                </span><br/>
-<span class="not-covered" title="0 out of 10 forms covered">
-                080&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(index-vertices&nbsp;(assoc&nbsp;s&nbsp;(:id&nbsp;o&#x27;)&nbsp;o&#x27;)&nbsp;o&#x27;))
-                </span><br/>
-<span class="not-covered" title="0 out of 14 forms covered">
-                081&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(coll?&nbsp;o)&nbsp;(reduce&nbsp;u&#x2F;deep-merge&nbsp;(map&nbsp;#(add-to-superstructure&nbsp;s&nbsp;%)&nbsp;o))
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(nil?&nbsp;o)&nbsp;o
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else
-                </span><br/>
-<span class="not-covered" title="0 out of 13 forms covered">
-                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.&nbsp;(str&nbsp;&quot;Don&#x27;t&nbsp;know&nbsp;how&nbsp;to&nbsp;index&nbsp;&quot;&nbsp;(or&nbsp;(type&nbsp;o)&nbsp;&quot;nil&quot;)))))))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                085&nbsp;&nbsp;
+                183&nbsp;&nbsp;
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/svg.clj.html b/docs/cloverage/walkmap/svg.clj.html
index 2d0b77e..c04a8b4 100644
--- a/docs/cloverage/walkmap/svg.clj.html
+++ b/docs/cloverage/walkmap/svg.clj.html
@@ -17,316 +17,322 @@
                 004&nbsp;&nbsp;&nbsp;&nbsp;(SVG).&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                005&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.string&nbsp;:as&nbsp;s]
+                005&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.java.io&nbsp;:as&nbsp;io]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[dali.io&nbsp;:as&nbsp;neatly-folded-clock]
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.string&nbsp;:as&nbsp;s]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[hiccup.core&nbsp;:refer&nbsp;[html]]
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.xml&nbsp;:as&nbsp;x]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l&nbsp;:refer&nbsp;[info&nbsp;error&nbsp;spy]]
+                008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[dali.io&nbsp;:as&nbsp;neatly-folded-clock]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                009&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.ocean&nbsp;:refer&nbsp;[cull-ocean-facets]]
+                009&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[hiccup.core&nbsp;:refer&nbsp;[html]]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                010&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:refer&nbsp;[polygon?]]
+                010&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l&nbsp;:refer&nbsp;[info&nbsp;error&nbsp;spy]]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.stl&nbsp;:refer&nbsp;[decode-binary-stl]]
+                011&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.ocean&nbsp;:refer&nbsp;[cull-ocean-facets]]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[vertex?]]))
+                012&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:refer&nbsp;[polygon?]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.stl&nbsp;:refer&nbsp;[decode-binary-stl]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                014&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:refer&nbsp;[vertex?]]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                013&nbsp;&nbsp;
+                015&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                014&nbsp;&nbsp;(def&nbsp;^:dynamic&nbsp;*preferred-svg-render*
+                016&nbsp;&nbsp;(def&nbsp;^:dynamic&nbsp;*preferred-svg-render*
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                015&nbsp;&nbsp;&nbsp;&nbsp;&quot;Mainly&nbsp;for&nbsp;debugging&nbsp;dali;&nbsp;switch&nbsp;SVG&nbsp;renderer&nbsp;to&nbsp;use.&nbsp;Expected&nbsp;values:
+                017&nbsp;&nbsp;&nbsp;&nbsp;&quot;Mainly&nbsp;for&nbsp;debugging&nbsp;dali;&nbsp;switch&nbsp;SVG&nbsp;renderer&nbsp;to&nbsp;use.&nbsp;Expected&nbsp;values:
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                016&nbsp;&nbsp;&nbsp;&nbsp;`:dali`,&nbsp;`:hiccup`.&quot;
+                018&nbsp;&nbsp;&nbsp;&nbsp;`:dali`,&nbsp;`:hiccup`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                017&nbsp;&nbsp;&nbsp;&nbsp;:dali)
+                019&nbsp;&nbsp;&nbsp;&nbsp;:dali)
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                018&nbsp;&nbsp;
+                020&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                019&nbsp;&nbsp;(defn-&nbsp;facet-&gt;svg-poly
+                021&nbsp;&nbsp;(defn-&nbsp;facet-&gt;svg-poly
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                020&nbsp;&nbsp;&nbsp;&nbsp;[facet]
+                022&nbsp;&nbsp;&nbsp;&nbsp;[facet]
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                021&nbsp;&nbsp;&nbsp;&nbsp;[:polygon
+                023&nbsp;&nbsp;&nbsp;&nbsp;[:polygon
                 </span><br/>
 <span class="not-covered" title="0 out of 20 forms covered">
-                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:points&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;#(str&nbsp;(:x&nbsp;%)&nbsp;&quot;,&quot;&nbsp;(:y&nbsp;%))&nbsp;(:vertices&nbsp;facet)))}])
+                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:points&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;#(str&nbsp;(:x&nbsp;%)&nbsp;&quot;,&quot;&nbsp;(:y&nbsp;%))&nbsp;(:vertices&nbsp;facet)))}])
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                023&nbsp;&nbsp;
+                025&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                024&nbsp;&nbsp;(defn-&nbsp;dali-facet-&gt;svg-poly
+                026&nbsp;&nbsp;(defn-&nbsp;dali-facet-&gt;svg-poly
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                025&nbsp;&nbsp;&nbsp;&nbsp;[facet]
+                027&nbsp;&nbsp;&nbsp;&nbsp;[facet]
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                026&nbsp;&nbsp;&nbsp;&nbsp;(vec
+                028&nbsp;&nbsp;&nbsp;&nbsp;(vec
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                027&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
+                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                028&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:polygon
+                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:polygon
                 </span><br/>
 <span class="not-covered" title="0 out of 16 forms covered">
-                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map&nbsp;#(vec&nbsp;(list&nbsp;(:x&nbsp;%)&nbsp;(:y&nbsp;%)))&nbsp;(:vertices&nbsp;facet)))))
+                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map&nbsp;#(vec&nbsp;(list&nbsp;(:x&nbsp;%)&nbsp;(:y&nbsp;%)))&nbsp;(:vertices&nbsp;facet)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                030&nbsp;&nbsp;
+                032&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                031&nbsp;&nbsp;(defn&nbsp;dali-stl-&gt;svg
+                033&nbsp;&nbsp;(defn&nbsp;dali-stl-&gt;svg
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                032&nbsp;&nbsp;&nbsp;&nbsp;&quot;Format&nbsp;this&nbsp;`stl`&nbsp;as&nbsp;SVG&nbsp;for&nbsp;the&nbsp;`dali`&nbsp;renderer&nbsp;on&nbsp;a&nbsp;page&nbsp;with&nbsp;these
+                034&nbsp;&nbsp;&nbsp;&nbsp;&quot;Format&nbsp;this&nbsp;`stl`&nbsp;as&nbsp;SVG&nbsp;for&nbsp;the&nbsp;`dali`&nbsp;renderer&nbsp;on&nbsp;a&nbsp;page&nbsp;with&nbsp;these
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                033&nbsp;&nbsp;&nbsp;&nbsp;bounds.&quot;
+                035&nbsp;&nbsp;&nbsp;&nbsp;bounds.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                034&nbsp;&nbsp;&nbsp;&nbsp;[stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy]
+                036&nbsp;&nbsp;&nbsp;&nbsp;[stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy]
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                035&nbsp;&nbsp;&nbsp;&nbsp;[:dali&#x2F;page
+                037&nbsp;&nbsp;&nbsp;&nbsp;[:dali&#x2F;page
                 </span><br/>
 <span class="not-covered" title="0 out of 8 forms covered">
-                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:xmlns&nbsp;&quot;http:&#x2F;&#x2F;www.w3.org&#x2F;2000&#x2F;svg&quot;
+                038&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:xmlns&nbsp;&quot;http:&#x2F;&#x2F;www.w3.org&#x2F;2000&#x2F;svg&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                037&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:version&nbsp;&quot;1.2&quot;
+                039&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:version&nbsp;&quot;1.2&quot;
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                038&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:width&nbsp;(-&nbsp;maxx&nbsp;minx)
+                040&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:width&nbsp;(-&nbsp;maxx&nbsp;minx)
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                039&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:height&nbsp;(-&nbsp;maxy&nbsp;miny)
+                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:height&nbsp;(-&nbsp;maxy&nbsp;miny)
                 </span><br/>
 <span class="not-covered" title="0 out of 11 forms covered">
-                040&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:viewBox&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;str&nbsp;[minx&nbsp;miny&nbsp;maxx&nbsp;maxy]))}
+                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:viewBox&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;str&nbsp;[minx&nbsp;miny&nbsp;maxx&nbsp;maxy]))}
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vec
+                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vec
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
+                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:g
+                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:g
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dali-facet-&gt;svg-poly
+                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;dali-facet-&gt;svg-poly
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl))))])
+                048&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl))))])
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                047&nbsp;&nbsp;
+                049&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                048&nbsp;&nbsp;(defn&nbsp;hiccup-stl-&gt;svg
+                050&nbsp;&nbsp;(defn&nbsp;hiccup-stl-&gt;svg
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                049&nbsp;&nbsp;&nbsp;&nbsp;&quot;Format&nbsp;this&nbsp;`stl`&nbsp;as&nbsp;SVG&nbsp;for&nbsp;the&nbsp;`hiccup`&nbsp;renderer&nbsp;on&nbsp;a&nbsp;page&nbsp;with&nbsp;these
+                051&nbsp;&nbsp;&nbsp;&nbsp;&quot;Format&nbsp;this&nbsp;`stl`&nbsp;as&nbsp;SVG&nbsp;for&nbsp;the&nbsp;`hiccup`&nbsp;renderer&nbsp;on&nbsp;a&nbsp;page&nbsp;with&nbsp;these
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                050&nbsp;&nbsp;&nbsp;&nbsp;bounds.&quot;
+                052&nbsp;&nbsp;&nbsp;&nbsp;bounds.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                051&nbsp;&nbsp;&nbsp;&nbsp;[stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy]
+                053&nbsp;&nbsp;&nbsp;&nbsp;[stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy]
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                052&nbsp;&nbsp;&nbsp;&nbsp;[:svg
+                054&nbsp;&nbsp;&nbsp;&nbsp;[:svg
                 </span><br/>
 <span class="not-covered" title="0 out of 8 forms covered">
-                053&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:xmlns&nbsp;&quot;http:&#x2F;&#x2F;www.w3.org&#x2F;2000&#x2F;svg&quot;
+                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{:xmlns&nbsp;&quot;http:&#x2F;&#x2F;www.w3.org&#x2F;2000&#x2F;svg&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:version&nbsp;&quot;1.2&quot;
+                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:version&nbsp;&quot;1.2&quot;
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:width&nbsp;(-&nbsp;maxx&nbsp;minx)
+                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:width&nbsp;(-&nbsp;maxx&nbsp;minx)
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:height&nbsp;(-&nbsp;maxy&nbsp;miny)
+                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:height&nbsp;(-&nbsp;maxy&nbsp;miny)
                 </span><br/>
 <span class="not-covered" title="0 out of 11 forms covered">
-                057&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:viewBox&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;str&nbsp;[minx&nbsp;miny&nbsp;maxx&nbsp;maxy]))}
+                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:viewBox&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;(map&nbsp;str&nbsp;[minx&nbsp;miny&nbsp;maxx&nbsp;maxy]))}
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vec
+                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vec
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
+                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cons
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:g
+                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:g
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;facet-&gt;svg-poly
+                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;facet-&gt;svg-poly
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl))))])
+                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl))))])
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                064&nbsp;&nbsp;
+                066&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                065&nbsp;&nbsp;(defn&nbsp;stl-&gt;svg
+                067&nbsp;&nbsp;(defn&nbsp;stl-&gt;svg
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                066&nbsp;&nbsp;&nbsp;&nbsp;&quot;Convert&nbsp;this&nbsp;in-memory&nbsp;`stl`&nbsp;structure,&nbsp;as&nbsp;read&nbsp;by&nbsp;`decode-binary-stl`,&nbsp;into
+                068&nbsp;&nbsp;&nbsp;&nbsp;&quot;Convert&nbsp;this&nbsp;in-memory&nbsp;`stl`&nbsp;structure,&nbsp;as&nbsp;read&nbsp;by&nbsp;`decode-binary-stl`,&nbsp;into
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                067&nbsp;&nbsp;&nbsp;&nbsp;an&nbsp;in-memory&nbsp;hiccup&nbsp;representation&nbsp;of&nbsp;SVG&nbsp;structure,&nbsp;and&nbsp;return&nbsp;it.&quot;
+                069&nbsp;&nbsp;&nbsp;&nbsp;an&nbsp;in-memory&nbsp;hiccup&nbsp;representation&nbsp;of&nbsp;SVG&nbsp;structure,&nbsp;and&nbsp;return&nbsp;it.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                068&nbsp;&nbsp;&nbsp;&nbsp;[stl]
+                070&nbsp;&nbsp;&nbsp;&nbsp;[stl]
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                069&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[minx&nbsp;(reduce
+                071&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[minx&nbsp;(reduce
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                070&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;min
+                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;min
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                071&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                073&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 9 forms covered">
-                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;min&nbsp;(map&nbsp;:x&nbsp;(:vertices&nbsp;%)))
+                074&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;min&nbsp;(map&nbsp;:x&nbsp;(:vertices&nbsp;%)))
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                073&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
+                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                074&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;maxx&nbsp;(reduce
+                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;maxx&nbsp;(reduce
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;max
+                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;max
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 9 forms covered">
-                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;max&nbsp;(map&nbsp;:x&nbsp;(:vertices&nbsp;%)))
+                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;max&nbsp;(map&nbsp;:x&nbsp;(:vertices&nbsp;%)))
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
+                080&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;miny&nbsp;(reduce
+                081&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;miny&nbsp;(reduce
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                080&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;min
+                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;min
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                081&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 9 forms covered">
-                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;min&nbsp;(map&nbsp;:y&nbsp;(:vertices&nbsp;%)))
+                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;min&nbsp;(map&nbsp;:y&nbsp;(:vertices&nbsp;%)))
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
+                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;maxy&nbsp;(reduce
+                086&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;maxy&nbsp;(reduce
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;max
+                087&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;max
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                086&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                088&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
                 </span><br/>
 <span class="not-covered" title="0 out of 9 forms covered">
-                087&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;max&nbsp;(map&nbsp;:y&nbsp;(:vertices&nbsp;%)))
+                089&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(reduce&nbsp;max&nbsp;(map&nbsp;:y&nbsp;(:vertices&nbsp;%)))
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                088&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))]
+                090&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:facets&nbsp;stl)))]
                 </span><br/>
 <span class="not-covered" title="0 out of 17 forms covered">
-                089&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;info&nbsp;&quot;Generating&nbsp;SVG&nbsp;for&nbsp;&quot;&nbsp;*preferred-svg-render*&nbsp;&quot;&nbsp;renderer&quot;)
+                091&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;info&nbsp;&quot;Generating&nbsp;SVG&nbsp;for&nbsp;&quot;&nbsp;*preferred-svg-render*&nbsp;&quot;&nbsp;renderer&quot;)
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                090&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(case&nbsp;*preferred-svg-render*
+                092&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(case&nbsp;*preferred-svg-render*
                 </span><br/>
 <span class="not-covered" title="0 out of 7 forms covered">
-                091&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:hiccup&nbsp;(hiccup-stl-&gt;svg&nbsp;stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy)
+                093&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:hiccup&nbsp;(hiccup-stl-&gt;svg&nbsp;stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy)
                 </span><br/>
 <span class="not-covered" title="0 out of 7 forms covered">
-                092&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:dali&nbsp;(dali-stl-&gt;svg&nbsp;stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy)
+                094&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:dali&nbsp;(dali-stl-&gt;svg&nbsp;stl&nbsp;minx&nbsp;maxx&nbsp;miny&nbsp;maxy)
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                093&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(Exception.&nbsp;&quot;Unexpected&nbsp;renderer&nbsp;value:&nbsp;&quot;&nbsp;*preferred-svg-render*)))))
+                095&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(Exception.&nbsp;&quot;Unexpected&nbsp;renderer&nbsp;value:&nbsp;&quot;&nbsp;*preferred-svg-render*)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                094&nbsp;&nbsp;
+                096&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                095&nbsp;&nbsp;(defn&nbsp;binary-stl-file-&gt;svg
+                097&nbsp;&nbsp;(defn&nbsp;binary-stl-file-&gt;svg
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                096&nbsp;&nbsp;&nbsp;&nbsp;&quot;Given&nbsp;only&nbsp;an&nbsp;`in-filename`,&nbsp;parse&nbsp;the&nbsp;indicated&nbsp;file,&nbsp;expected&nbsp;to&nbsp;be
+                098&nbsp;&nbsp;&nbsp;&nbsp;&quot;Given&nbsp;only&nbsp;an&nbsp;`in-filename`,&nbsp;parse&nbsp;the&nbsp;indicated&nbsp;file,&nbsp;expected&nbsp;to&nbsp;be
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                097&nbsp;&nbsp;&nbsp;&nbsp;binary&nbsp;STL,&nbsp;and&nbsp;return&nbsp;an&nbsp;equivalent&nbsp;SVG&nbsp;structure.&nbsp;Given&nbsp;both&nbsp;`in-filename`
+                099&nbsp;&nbsp;&nbsp;&nbsp;binary&nbsp;STL,&nbsp;and&nbsp;return&nbsp;an&nbsp;equivalent&nbsp;SVG&nbsp;structure.&nbsp;Given&nbsp;both&nbsp;`in-filename`
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                098&nbsp;&nbsp;&nbsp;&nbsp;and&nbsp;`out-filename`,&nbsp;as&nbsp;side-effect&nbsp;write&nbsp;the&nbsp;SVG&nbsp;to&nbsp;the&nbsp;indicated&nbsp;output&nbsp;file.&quot;
+                100&nbsp;&nbsp;&nbsp;&nbsp;and&nbsp;`out-filename`,&nbsp;as&nbsp;side-effect&nbsp;write&nbsp;the&nbsp;SVG&nbsp;to&nbsp;the&nbsp;indicated&nbsp;output&nbsp;file.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                099&nbsp;&nbsp;&nbsp;&nbsp;([in-filename]
+                101&nbsp;&nbsp;&nbsp;&nbsp;([in-filename]
                 </span><br/>
 <span class="not-covered" title="0 out of 7 forms covered">
-                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl-&gt;svg&nbsp;(cull-ocean-facets&nbsp;(decode-binary-stl&nbsp;in-filename))))
+                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(stl-&gt;svg&nbsp;(cull-ocean-facets&nbsp;(decode-binary-stl&nbsp;in-filename))))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                101&nbsp;&nbsp;&nbsp;&nbsp;([in-filename&nbsp;out-filename]
+                103&nbsp;&nbsp;&nbsp;&nbsp;([in-filename&nbsp;out-filename]
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[s&nbsp;(binary-stl-file-&gt;svg&nbsp;in-filename)]
+                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[s&nbsp;(binary-stl-file-&gt;svg&nbsp;in-filename)]
                 </span><br/>
 <span class="not-covered" title="0 out of 17 forms covered">
-                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;info&nbsp;&quot;Emitting&nbsp;SVG&nbsp;with&nbsp;&quot;&nbsp;*preferred-svg-render*&nbsp;&quot;&nbsp;renderer&quot;)
+                105&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;info&nbsp;&quot;Emitting&nbsp;SVG&nbsp;with&nbsp;&quot;&nbsp;*preferred-svg-render*&nbsp;&quot;&nbsp;renderer&quot;)
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(case&nbsp;*preferred-svg-render*
+                106&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(case&nbsp;*preferred-svg-render*
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                105&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:dali&nbsp;(neatly-folded-clock&#x2F;render-svg&nbsp;s&nbsp;out-filename)
+                107&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:dali&nbsp;(neatly-folded-clock&#x2F;render-svg&nbsp;s&nbsp;out-filename)
                 </span><br/>
 <span class="not-covered" title="0 out of 8 forms covered">
-                106&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:hiccup&nbsp;(spit&nbsp;out-filename&nbsp;(html&nbsp;s))
+                108&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:hiccup&nbsp;(spit&nbsp;out-filename&nbsp;(html&nbsp;s))
                 </span><br/>
 <span class="not-covered" title="0 out of 4 forms covered">
-                107&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(Exception.&nbsp;&quot;Unexpected&nbsp;renderer&nbsp;value:&nbsp;&quot;&nbsp;*preferred-svg-render*)))
+                109&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(Exception.&nbsp;&quot;Unexpected&nbsp;renderer&nbsp;value:&nbsp;&quot;&nbsp;*preferred-svg-render*)))
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                108&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;s)))
+                110&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;s)))
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/tag.clj.html b/docs/cloverage/walkmap/tag.clj.html
index a395271..32a0cd8 100644
--- a/docs/cloverage/walkmap/tag.clj.html
+++ b/docs/cloverage/walkmap/tag.clj.html
@@ -17,187 +17,196 @@
                 004&nbsp;&nbsp;&nbsp;&nbsp;This&nbsp;is&nbsp;in&nbsp;an&nbsp;attempt&nbsp;to&nbsp;avoid&nbsp;name&nbsp;clashes&nbsp;with&nbsp;other&nbsp;uses&nbsp;of&nbsp;this&nbsp;key.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                005&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.set&nbsp;:refer&nbsp;[difference&nbsp;union]]))
+                005&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.set&nbsp;:refer&nbsp;[difference&nbsp;union]]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:refer&nbsp;[kind-type]]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                006&nbsp;&nbsp;
+                008&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                007&nbsp;&nbsp;(defn&nbsp;tagged?
+                009&nbsp;&nbsp;(defn&nbsp;tagged?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                008&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;this&nbsp;`object`&nbsp;is&nbsp;tagged&nbsp;with&nbsp;each&nbsp;of&nbsp;these&nbsp;`tags`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error
+                010&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;this&nbsp;`object`&nbsp;is&nbsp;tagged&nbsp;with&nbsp;each&nbsp;of&nbsp;these&nbsp;`tags`.&nbsp;It&nbsp;is&nbsp;an&nbsp;error
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                009&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown)&nbsp;if
+                011&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown)&nbsp;if
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                010&nbsp;&nbsp;
+                012&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`object`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
+                013&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`object`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;any&nbsp;of&nbsp;`tags`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword.&quot;
+                014&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;any&nbsp;of&nbsp;`tags`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                013&nbsp;&nbsp;&nbsp;&nbsp;[object&nbsp;&amp;&nbsp;tags]
+                015&nbsp;&nbsp;&nbsp;&nbsp;[object&nbsp;&amp;&nbsp;tags]
                 </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                014&nbsp;&nbsp;&nbsp;&nbsp;(if
+<span class="covered" title="6 out of 6 forms covered">
+                016&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(map?&nbsp;object)
                 </span><br/>
-<span class="covered" title="3 out of 3 forms covered">
-                015&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;object)
+<span class="covered" title="2 out of 2 forms covered">
+                017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                016&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
+<span class="covered" title="6 out of 6 forms covered">
+                018&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;map:&nbsp;&quot;&nbsp;(kind-type&nbsp;object)))))
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;keyword?&nbsp;tags)
+                019&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[tags&#x27;&nbsp;(flatten&nbsp;tags)]
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(every?&nbsp;keyword?&nbsp;tags&#x27;)
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;keywords:&nbsp;&quot;&nbsp;(map&nbsp;kind-type&nbsp;tags&#x27;)))))
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                018&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[ot&nbsp;(::tags&nbsp;object)]
+                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[ot&nbsp;(::tags&nbsp;object)]
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                019&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(set?&nbsp;ot)
+                025&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(set?&nbsp;ot)
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;ot&nbsp;tags)))
+                026&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;ot&nbsp;tags&#x27;)))))
                 </span><br/>
-<span class="covered" title="2 out of 2 forms covered">
-                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+<span class="blank" title="0 out of 0 forms covered">
+                027&nbsp;&nbsp;
                 </span><br/>
-<span class="covered" title="7 out of 7 forms covered">
-                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;keyword(s):&nbsp;&quot;&nbsp;(map&nbsp;type&nbsp;tags)))))
+<span class="covered" title="1 out of 1 forms covered">
+                028&nbsp;&nbsp;(defn&nbsp;tag
                 </span><br/>
-<span class="covered" title="2 out of 2 forms covered">
-                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+<span class="not-tracked" title="0 out of 0 forms covered">
+                029&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;object&nbsp;like&nbsp;this&nbsp;`object`&nbsp;but&nbsp;with&nbsp;these&nbsp;`tags`&nbsp;added&nbsp;to&nbsp;its&nbsp;tags,
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                030&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;they&nbsp;are&nbsp;not&nbsp;already&nbsp;present.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                031&nbsp;&nbsp;&nbsp;&nbsp;thrown)&nbsp;if
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                032&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                033&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`object`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                034&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;any&nbsp;of&nbsp;`tags`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword&nbsp;or&nbsp;sequence&nbsp;of&nbsp;keywords.
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                035&nbsp;&nbsp;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                036&nbsp;&nbsp;&nbsp;&nbsp;It&#x27;s&nbsp;legal&nbsp;to&nbsp;include&nbsp;sequences&nbsp;of&nbsp;keywords&nbsp;in&nbsp;`tags`,&nbsp;so&nbsp;that&nbsp;users&nbsp;can&nbsp;do
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                037&nbsp;&nbsp;&nbsp;&nbsp;useful&nbsp;things&nbsp;like&nbsp;`(tag&nbsp;obj&nbsp;(map&nbsp;keyword&nbsp;some-strings))`.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                038&nbsp;&nbsp;&nbsp;&nbsp;[object&nbsp;&amp;&nbsp;tags]
+                </span><br/>
+<span class="covered" title="20 out of 20 forms covered">
+                039&nbsp;&nbsp;&nbsp;&nbsp;(l&#x2F;debug&nbsp;&quot;Tagging&quot;&nbsp;(kind-type&nbsp;object)&nbsp;&quot;with&quot;&nbsp;tags)
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                025&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;map:&nbsp;&quot;&nbsp;(type&nbsp;object))))))
+                040&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(map?&nbsp;object)
                 </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                026&nbsp;&nbsp;
+<span class="covered" title="2 out of 2 forms covered">
+                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                027&nbsp;&nbsp;(defn&nbsp;tag
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                028&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;object&nbsp;like&nbsp;this&nbsp;`object`&nbsp;but&nbsp;with&nbsp;these&nbsp;`tags`&nbsp;added&nbsp;to&nbsp;its&nbsp;tags,
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                029&nbsp;&nbsp;&nbsp;&nbsp;if&nbsp;they&nbsp;are&nbsp;not&nbsp;already&nbsp;present.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                030&nbsp;&nbsp;&nbsp;&nbsp;thrown)&nbsp;if
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                031&nbsp;&nbsp;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                032&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`object`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                033&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;any&nbsp;of&nbsp;`tags`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                034&nbsp;&nbsp;&nbsp;&nbsp;[object&nbsp;&amp;&nbsp;tags]
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                035&nbsp;&nbsp;&nbsp;&nbsp;(if
-                </span><br/>
-<span class="covered" title="3 out of 3 forms covered">
-                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;object)
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                037&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
+<span class="covered" title="6 out of 6 forms covered">
+                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;map:&nbsp;&quot;&nbsp;(kind-type&nbsp;object)))))
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                038&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;keyword?&nbsp;tags)
-                </span><br/>
-<span class="covered" title="12 out of 12 forms covered">
-                039&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;object&nbsp;::tags&nbsp;(union&nbsp;(set&nbsp;tags)&nbsp;(::tags&nbsp;object)))
-                </span><br/>
-<span class="covered" title="2 out of 2 forms covered">
-                040&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                043&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[tags&#x27;&nbsp;(flatten&nbsp;tags)]
                 </span><br/>
 <span class="covered" title="7 out of 7 forms covered">
-                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;keyword(s):&nbsp;&quot;&nbsp;(map&nbsp;type&nbsp;tags)))))
+                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(every?&nbsp;keyword?&nbsp;tags&#x27;)
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="covered" title="6 out of 6 forms covered">
-                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;map:&nbsp;&quot;&nbsp;(type&nbsp;object))))))
+<span class="covered" title="7 out of 7 forms covered">
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;keywords:&nbsp;&quot;&nbsp;(map&nbsp;kind-type&nbsp;tags&#x27;)))))
+                </span><br/>
+<span class="covered" title="12 out of 12 forms covered">
+                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;object&nbsp;::tags&nbsp;(union&nbsp;(set&nbsp;tags&#x27;)&nbsp;(::tags&nbsp;object)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                044&nbsp;&nbsp;
+                048&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="15 out of 15 forms covered">
-                045&nbsp;&nbsp;(defmacro&nbsp;tags
+                049&nbsp;&nbsp;(defmacro&nbsp;tags
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                046&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;tags&nbsp;of&nbsp;this&nbsp;object,&nbsp;if&nbsp;any.&quot;
+                050&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;the&nbsp;tags&nbsp;of&nbsp;this&nbsp;object,&nbsp;if&nbsp;any.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                047&nbsp;&nbsp;&nbsp;&nbsp;[object]
+                051&nbsp;&nbsp;&nbsp;&nbsp;[object]
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                048&nbsp;&nbsp;&nbsp;&nbsp;`(::tags&nbsp;~object))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                049&nbsp;&nbsp;
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                050&nbsp;&nbsp;(defn&nbsp;untag
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                051&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;object&nbsp;like&nbsp;this&nbsp;`object`&nbsp;but&nbsp;with&nbsp;these&nbsp;`tags`&nbsp;removed&nbsp;from&nbsp;its
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                052&nbsp;&nbsp;&nbsp;&nbsp;tags,&nbsp;if&nbsp;present.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown)&nbsp;if
+                052&nbsp;&nbsp;&nbsp;&nbsp;`(::tags&nbsp;~object))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
                 053&nbsp;&nbsp;
                 </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                054&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`object`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                055&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;any&nbsp;of&nbsp;`tags`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                056&nbsp;&nbsp;&nbsp;&nbsp;[object&nbsp;&amp;&nbsp;tags]
-                </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                057&nbsp;&nbsp;&nbsp;&nbsp;(if
+                054&nbsp;&nbsp;(defn&nbsp;untag
                 </span><br/>
-<span class="covered" title="3 out of 3 forms covered">
-                058&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;object)
+<span class="not-tracked" title="0 out of 0 forms covered">
+                055&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;an&nbsp;object&nbsp;like&nbsp;this&nbsp;`object`&nbsp;but&nbsp;with&nbsp;these&nbsp;`tags`&nbsp;removed&nbsp;from&nbsp;its
                 </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                059&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
+<span class="not-tracked" title="0 out of 0 forms covered">
+                056&nbsp;&nbsp;&nbsp;&nbsp;tags,&nbsp;if&nbsp;present.&nbsp;It&nbsp;is&nbsp;an&nbsp;error&nbsp;(and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown)&nbsp;if
                 </span><br/>
-<span class="covered" title="4 out of 4 forms covered">
-                060&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(every?&nbsp;keyword?&nbsp;tags)
+<span class="blank" title="0 out of 0 forms covered">
+                057&nbsp;&nbsp;
                 </span><br/>
-<span class="covered" title="12 out of 12 forms covered">
-                061&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;object&nbsp;::tags&nbsp;(difference&nbsp;(::tags&nbsp;object)&nbsp;(set&nbsp;tags)))
+<span class="not-tracked" title="0 out of 0 forms covered">
+                058&nbsp;&nbsp;&nbsp;&nbsp;1.&nbsp;`object`&nbsp;is&nbsp;not&nbsp;a&nbsp;map;
                 </span><br/>
-<span class="covered" title="2 out of 2 forms covered">
-                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+<span class="not-tracked" title="0 out of 0 forms covered">
+                059&nbsp;&nbsp;&nbsp;&nbsp;2.&nbsp;any&nbsp;of&nbsp;`tags`&nbsp;is&nbsp;not&nbsp;a&nbsp;keyword&nbsp;or&nbsp;sequence&nbsp;of&nbsp;keywords.&quot;
                 </span><br/>
-<span class="covered" title="7 out of 7 forms covered">
-                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;keywords:&nbsp;&quot;&nbsp;(map&nbsp;type&nbsp;tags)))))
-                </span><br/>
-<span class="covered" title="2 out of 2 forms covered">
-                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+<span class="not-tracked" title="0 out of 0 forms covered">
+                060&nbsp;&nbsp;&nbsp;&nbsp;[object&nbsp;&amp;&nbsp;tags]
                 </span><br/>
 <span class="covered" title="6 out of 6 forms covered">
-                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;map:&nbsp;&quot;&nbsp;(type&nbsp;object))))))
+                061&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(map?&nbsp;object)
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                062&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="covered" title="6 out of 6 forms covered">
+                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;a&nbsp;map:&nbsp;&quot;&nbsp;(kind-type&nbsp;object)))))
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                064&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[tags&#x27;&nbsp;(flatten&nbsp;tags)]
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(every?&nbsp;keyword?&nbsp;tags&#x27;)
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Must&nbsp;be&nbsp;keywords:&nbsp;&quot;&nbsp;(map&nbsp;kind-type&nbsp;tags&#x27;)))))
+                </span><br/>
+<span class="covered" title="12 out of 12 forms covered">
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;object&nbsp;::tags&nbsp;(difference&nbsp;(::tags&nbsp;object)&nbsp;(set&nbsp;tags&#x27;)))))
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/utils.clj.html b/docs/cloverage/walkmap/utils.clj.html
index 235c672..8a5a84d 100644
--- a/docs/cloverage/walkmap/utils.clj.html
+++ b/docs/cloverage/walkmap/utils.clj.html
@@ -11,67 +11,127 @@
                 002&nbsp;&nbsp;&nbsp;&nbsp;&quot;Miscellaneous&nbsp;utility&nbsp;functions.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                003&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.math.numeric-tower&nbsp;:as&nbsp;m]
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                004&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.path&nbsp;:as&nbsp;p]
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                005&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.polygon&nbsp;:as&nbsp;q]
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                006&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.vertex&nbsp;:as&nbsp;v]))
+                003&nbsp;&nbsp;&nbsp;&nbsp;(:require&nbsp;[clojure.math.numeric-tower&nbsp;:as&nbsp;m]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                007&nbsp;&nbsp;
+                004&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                008&nbsp;&nbsp;(defn&nbsp;deep-merge
+                005&nbsp;&nbsp;(defn&nbsp;deep-merge
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                009&nbsp;&nbsp;&nbsp;&nbsp;&quot;Recursively&nbsp;merges&nbsp;maps.&nbsp;If&nbsp;vals&nbsp;are&nbsp;not&nbsp;maps,&nbsp;the&nbsp;last&nbsp;value&nbsp;wins.&quot;
+                006&nbsp;&nbsp;&nbsp;&nbsp;&quot;Recursively&nbsp;merges&nbsp;maps.&nbsp;If&nbsp;vals&nbsp;are&nbsp;not&nbsp;maps,&nbsp;the&nbsp;last&nbsp;value&nbsp;wins.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                010&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;TODO:&nbsp;not&nbsp;my&nbsp;implementation,&nbsp;not&nbsp;sure&nbsp;I&nbsp;entirely&nbsp;trust&nbsp;it.
+                007&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;TODO:&nbsp;not&nbsp;my&nbsp;implementation,&nbsp;not&nbsp;sure&nbsp;I&nbsp;entirely&nbsp;trust&nbsp;it.
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;[&amp;&nbsp;vals]
+                008&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;TODO&nbsp;TODO:&nbsp;if&nbsp;we&nbsp;are&nbsp;to&nbsp;successfully&nbsp;merge&nbsp;walkmap&nbsp;objects,&nbsp;we&nbsp;must
                 </span><br/>
-<span class="not-covered" title="0 out of 5 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(every?&nbsp;map?&nbsp;vals)
+<span class="not-tracked" title="0 out of 0 forms covered">
+                009&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;return,&nbsp;on&nbsp;each&nbsp;object,&nbsp;the&nbsp;union&nbsp;of&nbsp;its&nbsp;tags&nbsp;if&nbsp;any.
                 </span><br/>
-<span class="not-covered" title="0 out of 5 forms covered">
-                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(apply&nbsp;merge-with&nbsp;deep-merge&nbsp;vals)
+<span class="not-tracked" title="0 out of 0 forms covered">
+                010&nbsp;&nbsp;&nbsp;&nbsp;[&amp;&nbsp;vals]
                 </span><br/>
-<span class="not-covered" title="0 out of 3 forms covered">
-                014&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(last&nbsp;vals)))
+<span class="covered" title="5 out of 5 forms covered">
+                011&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(every?&nbsp;map?&nbsp;vals)
+                </span><br/>
+<span class="covered" title="5 out of 5 forms covered">
+                012&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(apply&nbsp;merge-with&nbsp;deep-merge&nbsp;vals)
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                013&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(last&nbsp;vals)))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                015&nbsp;&nbsp;
+                014&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                016&nbsp;&nbsp;(defn&nbsp;vertices
+                015&nbsp;&nbsp;(defn&nbsp;truncate
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                017&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;an&nbsp;object&nbsp;with&nbsp;vertices,&nbsp;return&nbsp;those&nbsp;vertices,&nbsp;else&nbsp;nil.&quot;
+                016&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;string&nbsp;`s`&nbsp;is&nbsp;more&nbsp;than&nbsp;`n`&nbsp;characters&nbsp;long,&nbsp;return&nbsp;the&nbsp;first&nbsp;`n`
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                018&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                017&nbsp;&nbsp;&nbsp;&nbsp;characters;&nbsp;otherwise,&nbsp;return&nbsp;`s`.&quot;
                 </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                019&nbsp;&nbsp;&nbsp;&nbsp;(cond
+<span class="not-tracked" title="0 out of 0 forms covered">
+                018&nbsp;&nbsp;&nbsp;&nbsp;[s&nbsp;n]
                 </span><br/>
-<span class="not-covered" title="0 out of 6 forms covered">
-                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(v&#x2F;vertex?&nbsp;o)&nbsp;(list&nbsp;o)
+<span class="not-covered" title="0 out of 21 forms covered">
+                019&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(and&nbsp;(string?&nbsp;s)&nbsp;(number?&nbsp;n)&nbsp;(&gt;&nbsp;(count&nbsp;s)&nbsp;n))
                 </span><br/>
-<span class="not-covered" title="0 out of 6 forms covered">
-                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(q&#x2F;polygon?&nbsp;o)&nbsp;(:vertices&nbsp;o)
+<span class="not-covered" title="0 out of 5 forms covered">
+                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;s&nbsp;0&nbsp;n)
                 </span><br/>
-<span class="not-covered" title="0 out of 6 forms covered">
-                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(p&#x2F;path?&nbsp;o)&nbsp;(:vertices&nbsp;o)))
+<span class="not-covered" title="0 out of 1 forms covered">
+                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;s))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                023&nbsp;&nbsp;
+                022&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                023&nbsp;&nbsp;(defn&nbsp;kind-type
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                024&nbsp;&nbsp;&nbsp;&nbsp;&quot;Identify&nbsp;the&nbsp;type&nbsp;of&nbsp;an&nbsp;`object`,&nbsp;e.g.&nbsp;for&nbsp;logging.&nbsp;If&nbsp;it&nbsp;has&nbsp;a&nbsp;`:kind`&nbsp;key,
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                025&nbsp;&nbsp;&nbsp;&nbsp;it&#x27;s&nbsp;one&nbsp;of&nbsp;ours,&nbsp;and&nbsp;that&#x27;s&nbsp;what&nbsp;we&nbsp;want.&nbsp;Otherwise,&nbsp;we&nbsp;want&nbsp;its&nbsp;type;&nbsp;but
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                026&nbsp;&nbsp;&nbsp;&nbsp;the&nbsp;type&nbsp;of&nbsp;`nil`&nbsp;is&nbsp;`nil`,&nbsp;which&nbsp;doesn&#x27;t&nbsp;get&nbsp;printed&nbsp;when&nbsp;assembling&nbsp;error
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                027&nbsp;&nbsp;&nbsp;&nbsp;,essages,&nbsp;so&nbsp;return&nbsp;\&quot;nil\&quot;.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                028&nbsp;&nbsp;&nbsp;&nbsp;[object]
+                </span><br/>
+<span class="partial" title="14 out of 15 forms covered">
+                029&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(:kind&nbsp;object)&nbsp;(type&nbsp;object)&nbsp;&quot;nil&quot;))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                030&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                031&nbsp;&nbsp;(defn&nbsp;=ish
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                032&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;numbers&nbsp;`n1`,&nbsp;`n2`&nbsp;are&nbsp;roughly&nbsp;equal;&nbsp;that&nbsp;is&nbsp;to&nbsp;say,&nbsp;equal&nbsp;to
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                033&nbsp;&nbsp;&nbsp;&nbsp;within&nbsp;`tolerance`&nbsp;(defaults&nbsp;to&nbsp;one&nbsp;part&nbsp;in&nbsp;a&nbsp;million).&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                034&nbsp;&nbsp;&nbsp;&nbsp;([n1&nbsp;n2]
+                </span><br/>
+<span class="covered" title="11 out of 11 forms covered">
+                035&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(and&nbsp;(number?&nbsp;n1)&nbsp;(number?&nbsp;n2))
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                036&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[m&nbsp;(m&#x2F;abs&nbsp;(min&nbsp;n1&nbsp;n2))
+                </span><br/>
+<span class="covered" title="9 out of 9 forms covered">
+                037&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;t&nbsp;(if&nbsp;(zero?&nbsp;m)&nbsp;0.000001&nbsp;(*&nbsp;0.000001&nbsp;m))]
+                </span><br/>
+<span class="covered" title="5 out of 5 forms covered">
+                038&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(=ish&nbsp;n1&nbsp;n2&nbsp;t))
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                039&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(=&nbsp;n1&nbsp;n2)))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                040&nbsp;&nbsp;&nbsp;&nbsp;([n1&nbsp;n2&nbsp;tolerance]
+                </span><br/>
+<span class="covered" title="11 out of 11 forms covered">
+                041&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if&nbsp;(and&nbsp;(number?&nbsp;n1)&nbsp;(number?&nbsp;n2))
+                </span><br/>
+<span class="covered" title="9 out of 9 forms covered">
+                042&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(&lt;&nbsp;(m&#x2F;abs&nbsp;(-&nbsp;n1&nbsp;n2))&nbsp;tolerance)
+                </span><br/>
+<span class="covered" title="4 out of 4 forms covered">
+                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(=&nbsp;n1&nbsp;n2))))
                 </span><br/>
  </body>
 </html>
diff --git a/docs/cloverage/walkmap/vertex.clj.html b/docs/cloverage/walkmap/vertex.clj.html
index e9b80e8..2857af8 100644
--- a/docs/cloverage/walkmap/vertex.clj.html
+++ b/docs/cloverage/walkmap/vertex.clj.html
@@ -26,325 +26,427 @@
                 007&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[clojure.string&nbsp;:as&nbsp;s]
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.geometry&nbsp;:refer&nbsp;[=ish]]))
+                008&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[taoensso.timbre&nbsp;:as&nbsp;l]
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                009&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[walkmap.utils&nbsp;:refer&nbsp;[=ish&nbsp;kind-type&nbsp;truncate]]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                009&nbsp;&nbsp;
+                010&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                010&nbsp;&nbsp;(defn&nbsp;vertex-key
+                011&nbsp;&nbsp;(defn&nbsp;vertex-key
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                011&nbsp;&nbsp;&nbsp;&nbsp;&quot;Making&nbsp;sure&nbsp;we&nbsp;get&nbsp;the&nbsp;same&nbsp;key&nbsp;everytime&nbsp;we&nbsp;key&nbsp;a&nbsp;vertex&nbsp;with&nbsp;the&nbsp;same
+                012&nbsp;&nbsp;&nbsp;&nbsp;&quot;Making&nbsp;sure&nbsp;we&nbsp;get&nbsp;the&nbsp;same&nbsp;key&nbsp;everytime&nbsp;we&nbsp;key&nbsp;a&nbsp;vertex&nbsp;with&nbsp;the&nbsp;same
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                012&nbsp;&nbsp;&nbsp;&nbsp;coordinates.&nbsp;`o`&nbsp;must&nbsp;have&nbsp;numeric&nbsp;values&nbsp;for&nbsp;`:x`,&nbsp;`:y`,&nbsp;and&nbsp;optionally
+                013&nbsp;&nbsp;&nbsp;&nbsp;coordinates.&nbsp;`o`&nbsp;must&nbsp;have&nbsp;numeric&nbsp;values&nbsp;for&nbsp;`:x`,&nbsp;`:y`,&nbsp;and&nbsp;optionally
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                013&nbsp;&nbsp;&nbsp;&nbsp;`:z`;&nbsp;it&nbsp;is&nbsp;an&nbsp;error&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown&nbsp;if&nbsp;`o`&nbsp;does&nbsp;not
+                014&nbsp;&nbsp;&nbsp;&nbsp;`:z`;&nbsp;it&nbsp;is&nbsp;an&nbsp;error&nbsp;and&nbsp;an&nbsp;exception&nbsp;will&nbsp;be&nbsp;thrown&nbsp;if&nbsp;`o`&nbsp;does&nbsp;not
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                014&nbsp;&nbsp;&nbsp;&nbsp;conform&nbsp;to&nbsp;this&nbsp;specification.
+                015&nbsp;&nbsp;&nbsp;&nbsp;conform&nbsp;to&nbsp;this&nbsp;specification.
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                015&nbsp;&nbsp;
+                016&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                016&nbsp;&nbsp;&nbsp;&nbsp;**Note:**&nbsp;these&nbsp;keys&nbsp;can&nbsp;be&nbsp;quite&nbsp;long.&nbsp;No&nbsp;apology&nbsp;is&nbsp;made:&nbsp;it&nbsp;is&nbsp;required
+                017&nbsp;&nbsp;&nbsp;&nbsp;**Note:**&nbsp;these&nbsp;keys&nbsp;can&nbsp;be&nbsp;quite&nbsp;long.&nbsp;No&nbsp;apology&nbsp;is&nbsp;made:&nbsp;it&nbsp;is&nbsp;required
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                017&nbsp;&nbsp;&nbsp;&nbsp;that&nbsp;the&nbsp;same&nbsp;key&nbsp;can&nbsp;*never*&nbsp;refer&nbsp;to&nbsp;two&nbsp;different&nbsp;locations&nbsp;in&nbsp;space.&quot;
+                018&nbsp;&nbsp;&nbsp;&nbsp;that&nbsp;the&nbsp;same&nbsp;key&nbsp;can&nbsp;*never*&nbsp;refer&nbsp;to&nbsp;two&nbsp;different&nbsp;locations&nbsp;in&nbsp;space.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                018&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                019&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                019&nbsp;&nbsp;&nbsp;&nbsp;(keyword
+                020&nbsp;&nbsp;&nbsp;&nbsp;(keyword
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                020&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;replace
+                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;replace
                 </span><br/>
 <span class="partial" title="2 out of 3 forms covered">
-                021&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
+                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
                 </span><br/>
 <span class="partial" title="15 out of 17 forms covered">
-                022&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(:x&nbsp;o)&nbsp;(:y&nbsp;o)&nbsp;(:z&nbsp;o))
+                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(:x&nbsp;o)&nbsp;(:y&nbsp;o)&nbsp;(:z&nbsp;o))
                 </span><br/>
 <span class="covered" title="14 out of 14 forms covered">
-                023&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;vert_&quot;&nbsp;(:x&nbsp;o)&nbsp;&quot;_&quot;&nbsp;(:y&nbsp;o)&nbsp;&quot;_&quot;&nbsp;(:z&nbsp;o))
+                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;vert_&quot;&nbsp;(:x&nbsp;o)&nbsp;&quot;_&quot;&nbsp;(:y&nbsp;o)&nbsp;&quot;_&quot;&nbsp;(:z&nbsp;o))
                 </span><br/>
 <span class="partial" title="9 out of 10 forms covered">
-                024&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(:x&nbsp;o)&nbsp;(:y&nbsp;o))
+                025&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(:x&nbsp;o)&nbsp;(:y&nbsp;o))
                 </span><br/>
 <span class="covered" title="10 out of 10 forms covered">
-                025&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;vert_&quot;&nbsp;(:x&nbsp;o)&nbsp;&quot;_&quot;&nbsp;(:y&nbsp;o))
+                026&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;vert_&quot;&nbsp;(:x&nbsp;o)&nbsp;&quot;_&quot;&nbsp;(:y&nbsp;o))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                026&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else
+                027&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else
                 </span><br/>
 <span class="not-covered" title="0 out of 2 forms covered">
-                027&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                028&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="not-covered" title="0 out of 13 forms covered">
-                028&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))&nbsp;0&nbsp;80))))
+<span class="not-covered" title="0 out of 12 forms covered">
+                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(truncate&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))&nbsp;80))))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                029&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;.&quot;
+                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                030&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;-&quot;)))
+                031&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;-&quot;)))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                031&nbsp;&nbsp;
+                032&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                032&nbsp;&nbsp;(defn&nbsp;vertex?
+                033&nbsp;&nbsp;(defn&nbsp;vertex?
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                033&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;vertex.&nbsp;That&nbsp;is,&nbsp;essentially,
+                034&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`o`&nbsp;satisfies&nbsp;the&nbsp;conditions&nbsp;for&nbsp;a&nbsp;vertex.&nbsp;That&nbsp;is,&nbsp;essentially,
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                034&nbsp;&nbsp;&nbsp;&nbsp;that&nbsp;it&nbsp;must&nbsp;rerpresent&nbsp;a&nbsp;two-&nbsp;or&nbsp;three-&nbsp;dimensional&nbsp;vector.&nbsp;A&nbsp;vertex&nbsp;is
+                035&nbsp;&nbsp;&nbsp;&nbsp;that&nbsp;it&nbsp;must&nbsp;rerpresent&nbsp;a&nbsp;two-&nbsp;or&nbsp;three-&nbsp;dimensional&nbsp;vector.&nbsp;A&nbsp;vertex&nbsp;is
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                035&nbsp;&nbsp;&nbsp;&nbsp;shall&nbsp;be&nbsp;a&nbsp;map&nbsp;having&nbsp;at&nbsp;least&nbsp;the&nbsp;keys&nbsp;`:x`&nbsp;and&nbsp;`:y`,&nbsp;where&nbsp;the&nbsp;value&nbsp;of
+                036&nbsp;&nbsp;&nbsp;&nbsp;shall&nbsp;be&nbsp;a&nbsp;map&nbsp;having&nbsp;at&nbsp;least&nbsp;the&nbsp;keys&nbsp;`:x`&nbsp;and&nbsp;`:y`,&nbsp;where&nbsp;the&nbsp;value&nbsp;of
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                036&nbsp;&nbsp;&nbsp;&nbsp;those&nbsp;keys&nbsp;is&nbsp;a&nbsp;number.&nbsp;If&nbsp;the&nbsp;key&nbsp;`:z`&nbsp;is&nbsp;also&nbsp;present,&nbsp;its&nbsp;value&nbsp;must&nbsp;also
+                037&nbsp;&nbsp;&nbsp;&nbsp;those&nbsp;keys&nbsp;is&nbsp;a&nbsp;number.&nbsp;If&nbsp;the&nbsp;key&nbsp;`:z`&nbsp;is&nbsp;also&nbsp;present,&nbsp;its&nbsp;value&nbsp;must&nbsp;also
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                037&nbsp;&nbsp;&nbsp;&nbsp;be&nbsp;a&nbsp;number.
+                038&nbsp;&nbsp;&nbsp;&nbsp;be&nbsp;a&nbsp;number.
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                038&nbsp;&nbsp;
+                039&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                039&nbsp;&nbsp;&nbsp;&nbsp;The&nbsp;name&nbsp;&nbsp;`vector?`&nbsp;was&nbsp;not&nbsp;used&nbsp;as&nbsp;that&nbsp;would&nbsp;clash&nbsp;with&nbsp;a&nbsp;function&nbsp;of&nbsp;that
+                040&nbsp;&nbsp;&nbsp;&nbsp;The&nbsp;name&nbsp;&nbsp;`vector?`&nbsp;was&nbsp;not&nbsp;used&nbsp;as&nbsp;that&nbsp;would&nbsp;clash&nbsp;with&nbsp;a&nbsp;function&nbsp;of&nbsp;that
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                040&nbsp;&nbsp;&nbsp;&nbsp;name&nbsp;in&nbsp;`clojure.core`&nbsp;whose&nbsp;semantics&nbsp;are&nbsp;entirely&nbsp;different.&quot;
+                041&nbsp;&nbsp;&nbsp;&nbsp;name&nbsp;in&nbsp;`clojure.core`&nbsp;whose&nbsp;semantics&nbsp;are&nbsp;entirely&nbsp;different.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                041&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                042&nbsp;&nbsp;&nbsp;&nbsp;[o]
                 </span><br/>
 <span class="partial" title="23 out of 26 forms covered">
-                042&nbsp;&nbsp;&nbsp;&nbsp;(and
+                043&nbsp;&nbsp;&nbsp;&nbsp;(and
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                043&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
+                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                044&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:id&nbsp;o)
+                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:walkmap.id&#x2F;id&nbsp;o)
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                045&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:x&nbsp;o))
+                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:x&nbsp;o))
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                046&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:y&nbsp;o))
+                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:y&nbsp;o))
                 </span><br/>
 <span class="covered" title="14 out of 14 forms covered">
-                047&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:z&nbsp;o))&nbsp;(number?&nbsp;(:z&nbsp;o)))
+                048&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:z&nbsp;o))&nbsp;(number?&nbsp;(:z&nbsp;o)))
                 </span><br/>
 <span class="covered" title="9 out of 9 forms covered">
-                048&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:vertex))))
+                049&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:kind&nbsp;o))&nbsp;(=&nbsp;(:kind&nbsp;o)&nbsp;:vertex))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                049&nbsp;&nbsp;
+                050&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                050&nbsp;&nbsp;(defn&nbsp;vertex=
+                051&nbsp;&nbsp;(defn&nbsp;vertex=
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                051&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;vertices&nbsp;`v1`,&nbsp;`v2`&nbsp;represent&nbsp;the&nbsp;same&nbsp;vertex.&quot;
+                052&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;vertices&nbsp;`v1`,&nbsp;`v2`&nbsp;represent&nbsp;the&nbsp;same&nbsp;vertex.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                052&nbsp;&nbsp;&nbsp;&nbsp;[v1&nbsp;v2]
+                053&nbsp;&nbsp;&nbsp;&nbsp;[v1&nbsp;v2]
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                053&nbsp;&nbsp;&nbsp;&nbsp;(every?
+                054&nbsp;&nbsp;&nbsp;&nbsp;(every?
                 </span><br/>
 <span class="covered" title="8 out of 8 forms covered">
-                054&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(=ish&nbsp;(%&nbsp;v1)&nbsp;(%&nbsp;v2))
+                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(=ish&nbsp;(%&nbsp;v1)&nbsp;(%&nbsp;v2))
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                055&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[:x&nbsp;:y&nbsp;:z]))
+                056&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[:x&nbsp;:y&nbsp;:z]))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                056&nbsp;&nbsp;
+                057&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                057&nbsp;&nbsp;(defn&nbsp;vertex
+                058&nbsp;&nbsp;(defn&nbsp;vertex*
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                058&nbsp;&nbsp;&nbsp;&nbsp;&quot;Make&nbsp;a&nbsp;vertex&nbsp;with&nbsp;this&nbsp;`x`,&nbsp;`y`&nbsp;and&nbsp;(if&nbsp;provided)&nbsp;`z`&nbsp;values.&nbsp;Returns&nbsp;a&nbsp;map
+                059&nbsp;&nbsp;&nbsp;&nbsp;&quot;Return&nbsp;a&nbsp;vertex&nbsp;like&nbsp;`v1`,&nbsp;but&nbsp;with&nbsp;each&nbsp;of&nbsp;its&nbsp;coordinates&nbsp;multiplied
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                059&nbsp;&nbsp;&nbsp;&nbsp;with&nbsp;those&nbsp;values,&nbsp;plus&nbsp;a&nbsp;unique&nbsp;`:id`&nbsp;value,&nbsp;and&nbsp;`:kind`&nbsp;set&nbsp;to&nbsp;`:vertex`.
+                060&nbsp;&nbsp;&nbsp;&nbsp;by&nbsp;the&nbsp;equivalent&nbsp;vertex&nbsp;in&nbsp;`v2`.&quot;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                060&nbsp;&nbsp;&nbsp;&nbsp;It&#x27;s&nbsp;not&nbsp;necessary&nbsp;to&nbsp;use&nbsp;this&nbsp;function&nbsp;to&nbsp;create&nbsp;a&nbsp;vertex,&nbsp;but&nbsp;the&nbsp;`:id`
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                061&nbsp;&nbsp;&nbsp;&nbsp;must&nbsp;be&nbsp;present&nbsp;and&nbsp;must&nbsp;be&nbsp;unique.&quot;
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                062&nbsp;&nbsp;&nbsp;&nbsp;([x&nbsp;y]
-                </span><br/>
-<span class="covered" title="8 out of 8 forms covered">
-                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[v&nbsp;{:x&nbsp;x&nbsp;:y&nbsp;y&nbsp;:kind&nbsp;:vertex}]
-                </span><br/>
-<span class="covered" title="7 out of 7 forms covered">
-                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;v&nbsp;:id&nbsp;(vertex-key&nbsp;v))))
-                </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                065&nbsp;&nbsp;&nbsp;&nbsp;([x&nbsp;y&nbsp;z]
-                </span><br/>
-<span class="covered" title="9 out of 9 forms covered">
-                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[v&nbsp;(assoc&nbsp;(vertex&nbsp;x&nbsp;y)&nbsp;:z&nbsp;z)]
-                </span><br/>
-<span class="covered" title="7 out of 7 forms covered">
-                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;v&nbsp;:id&nbsp;(vertex-key&nbsp;v)))))
-                </span><br/>
-<span class="blank" title="0 out of 0 forms covered">
-                068&nbsp;&nbsp;
+                061&nbsp;&nbsp;&nbsp;&nbsp;[v1&nbsp;v2]
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                069&nbsp;&nbsp;(defn&nbsp;canonicalise
+                062&nbsp;&nbsp;&nbsp;&nbsp;(if
+                </span><br/>
+<span class="partial" title="9 out of 10 forms covered">
+                063&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and&nbsp;(vertex?&nbsp;v1)&nbsp;(vertex?&nbsp;v2))
+                </span><br/>
+<span class="covered" title="2 out of 2 forms covered">
+                064&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[f&nbsp;(fn&nbsp;[v1&nbsp;v2&nbsp;coord]
+                </span><br/>
+<span class="partial" title="9 out of 10 forms covered">
+                065&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(*&nbsp;(or&nbsp;(coord&nbsp;v1)&nbsp;0)
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                070&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;a&nbsp;map&nbsp;with&nbsp;numeric&nbsp;values&nbsp;for&nbsp;`:x`,&nbsp;`:y`&nbsp;and&nbsp;optionally&nbsp;`:z`,
+                066&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;;;&nbsp;one&nbsp;here&nbsp;is&nbsp;deliberate!
                 </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                071&nbsp;&nbsp;&nbsp;&nbsp;upgrade&nbsp;it&nbsp;to&nbsp;something&nbsp;we&nbsp;will&nbsp;recognise&nbsp;as&nbsp;a&nbsp;vertex.&quot;
+<span class="partial" title="7 out of 8 forms covered">
+                067&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(coord&nbsp;v2)&nbsp;1)))]
                 </span><br/>
-<span class="not-tracked" title="0 out of 0 forms covered">
-                072&nbsp;&nbsp;&nbsp;&nbsp;[o]
-                </span><br/>
-<span class="covered" title="1 out of 1 forms covered">
-                073&nbsp;&nbsp;&nbsp;&nbsp;(if
-                </span><br/>
-<span class="partial" title="13 out of 17 forms covered">
-                074&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
-                </span><br/>
-<span class="covered" title="3 out of 3 forms covered">
-                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
+<span class="covered" title="11 out of 11 forms covered">
+                068&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;v1&nbsp;:x&nbsp;(f&nbsp;v1&nbsp;v2&nbsp;:x)
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                076&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:x&nbsp;o))
+                069&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:y&nbsp;(f&nbsp;v1&nbsp;v2&nbsp;:y)
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                077&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:y&nbsp;o))
+                070&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:z&nbsp;(f&nbsp;v1&nbsp;v2&nbsp;:z)))
                 </span><br/>
-<span class="covered" title="9 out of 9 forms covered">
-                078&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:z&nbsp;o))&nbsp;(number?&nbsp;(:z&nbsp;o))))
-                </span><br/>
-<span class="covered" title="9 out of 9 forms covered">
-                079&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;o&nbsp;:kind&nbsp;:vertex&nbsp;:id&nbsp;(vertex-key&nbsp;o))
-                </span><br/>
-<span class="not-covered" title="0 out of 1 forms covered">
-                080&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw
-                </span><br/>
-<span class="not-covered" title="0 out of 1 forms covered">
-                081&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
-                </span><br/>
-<span class="not-covered" title="0 out of 4 forms covered">
-                082&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs
+<span class="not-covered" title="0 out of 15 forms covered">
+                071&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(do&nbsp;(l&#x2F;warn
                 </span><br/>
 <span class="not-covered" title="0 out of 3 forms covered">
-                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;proto-vertex:&nbsp;must&nbsp;have&nbsp;numeric&nbsp;`:x`&nbsp;and&nbsp;`:y`:&nbsp;&quot;
+                072&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                073&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&quot;&nbsp;&quot;
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                074&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&quot;in&nbsp;`vertex-multiply`,&nbsp;both&nbsp;must&nbsp;be&nbsp;vectors.&nbsp;v1:&quot;&nbsp;v1&nbsp;&quot;v2:&quot;&nbsp;v2]))
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                075&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;v1)))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                076&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                077&nbsp;&nbsp;(defn&nbsp;vertex
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                078&nbsp;&nbsp;&nbsp;&nbsp;&quot;Make&nbsp;a&nbsp;vertex&nbsp;with&nbsp;this&nbsp;`x`,&nbsp;`y`&nbsp;and&nbsp;(if&nbsp;provided)&nbsp;`z`&nbsp;values.&nbsp;Returns&nbsp;a&nbsp;map
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                079&nbsp;&nbsp;&nbsp;&nbsp;with&nbsp;those&nbsp;values,&nbsp;plus&nbsp;a&nbsp;unique&nbsp;`:walkmap.id&#x2F;id`&nbsp;value,&nbsp;and&nbsp;`:kind`&nbsp;set&nbsp;to&nbsp;`:vertex`.
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                080&nbsp;&nbsp;&nbsp;&nbsp;It&#x27;s&nbsp;not&nbsp;necessary&nbsp;to&nbsp;use&nbsp;this&nbsp;function&nbsp;to&nbsp;create&nbsp;a&nbsp;vertex,&nbsp;but&nbsp;the&nbsp;`:walkmap.id&#x2F;id`
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                081&nbsp;&nbsp;&nbsp;&nbsp;must&nbsp;be&nbsp;present&nbsp;and&nbsp;must&nbsp;be&nbsp;unique.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                082&nbsp;&nbsp;&nbsp;&nbsp;([x&nbsp;y]
+                </span><br/>
+<span class="covered" title="8 out of 8 forms covered">
+                083&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[v&nbsp;{:x&nbsp;x&nbsp;:y&nbsp;y&nbsp;:kind&nbsp;:vertex}]
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;v&nbsp;:walkmap.id&#x2F;id&nbsp;(vertex-key&nbsp;v))))
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                085&nbsp;&nbsp;&nbsp;&nbsp;([x&nbsp;y&nbsp;z]
+                </span><br/>
+<span class="covered" title="9 out of 9 forms covered">
+                086&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(let&nbsp;[v&nbsp;(assoc&nbsp;(vertex&nbsp;x&nbsp;y)&nbsp;:z&nbsp;z)]
+                </span><br/>
+<span class="covered" title="7 out of 7 forms covered">
+                087&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;v&nbsp;:walkmap.id&#x2F;id&nbsp;(vertex-key&nbsp;v)))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                088&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                089&nbsp;&nbsp;(defn&nbsp;canonicalise
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                090&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;a&nbsp;map&nbsp;with&nbsp;numeric&nbsp;values&nbsp;for&nbsp;`:x`,&nbsp;`:y`&nbsp;and&nbsp;optionally&nbsp;`:z`,
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                091&nbsp;&nbsp;&nbsp;&nbsp;upgrade&nbsp;it&nbsp;to&nbsp;something&nbsp;we&nbsp;will&nbsp;recognise&nbsp;as&nbsp;a&nbsp;vertex.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                092&nbsp;&nbsp;&nbsp;&nbsp;[o]
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                093&nbsp;&nbsp;&nbsp;&nbsp;(if
+                </span><br/>
+<span class="partial" title="13 out of 17 forms covered">
+                094&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(and
+                </span><br/>
+<span class="covered" title="3 out of 3 forms covered">
+                095&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map?&nbsp;o)
+                </span><br/>
+<span class="covered" title="5 out of 5 forms covered">
+                096&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:x&nbsp;o))
+                </span><br/>
+<span class="covered" title="5 out of 5 forms covered">
+                097&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(number?&nbsp;(:y&nbsp;o))
+                </span><br/>
+<span class="covered" title="9 out of 9 forms covered">
+                098&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;(nil?&nbsp;(:z&nbsp;o))&nbsp;(number?&nbsp;(:z&nbsp;o))))
+                </span><br/>
+<span class="covered" title="9 out of 9 forms covered">
+                099&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;o&nbsp;:kind&nbsp;:vertex&nbsp;:walkmap.id&#x2F;id&nbsp;(vertex-key&nbsp;o))
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw
+                </span><br/>
+<span class="not-covered" title="0 out of 1 forms covered">
+                101&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(truncate
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;proto-vertex:&nbsp;must&nbsp;have&nbsp;numeric&nbsp;`:x`&nbsp;and&nbsp;`:y`:&nbsp;&quot;
                 </span><br/>
 <span class="not-covered" title="0 out of 6 forms covered">
-                084&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))
+                104&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                085&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;0&nbsp;80)))))
+                105&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;80)))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                086&nbsp;&nbsp;
+                106&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                087&nbsp;&nbsp;(def&nbsp;ensure3d
+                107&nbsp;&nbsp;(def&nbsp;ensure3d
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                088&nbsp;&nbsp;&nbsp;&nbsp;&quot;Given&nbsp;a&nbsp;vertex&nbsp;`o`,&nbsp;if&nbsp;`o`&nbsp;has&nbsp;a&nbsp;`:z`&nbsp;value,&nbsp;just&nbsp;return&nbsp;`o`;&nbsp;otherwise
+                108&nbsp;&nbsp;&nbsp;&nbsp;&quot;Given&nbsp;a&nbsp;vertex&nbsp;`o`,&nbsp;if&nbsp;`o`&nbsp;has&nbsp;a&nbsp;`:z`&nbsp;value,&nbsp;just&nbsp;return&nbsp;`o`;&nbsp;otherwise
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                089&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;a&nbsp;vertex&nbsp;like&nbsp;`o`&nbsp;but&nbsp;having&nbsp;thie&nbsp;`dflt`&nbsp;value&nbsp;as&nbsp;the&nbsp;value&nbsp;of&nbsp;its
+                109&nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;a&nbsp;vertex&nbsp;like&nbsp;`o`&nbsp;but&nbsp;having&nbsp;thie&nbsp;`dflt`&nbsp;value&nbsp;as&nbsp;the&nbsp;value&nbsp;of&nbsp;its
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                090&nbsp;&nbsp;&nbsp;&nbsp;`:z`&nbsp;key,&nbsp;or&nbsp;zero&nbsp;as&nbsp;the&nbsp;value&nbsp;of&nbsp;its&nbsp;`:z`&nbsp;key&nbsp;if&nbsp;`dflt`&nbsp;is&nbsp;not&nbsp;specified.
+                110&nbsp;&nbsp;&nbsp;&nbsp;`:z`&nbsp;key,&nbsp;or&nbsp;zero&nbsp;as&nbsp;the&nbsp;value&nbsp;of&nbsp;its&nbsp;`:z`&nbsp;key&nbsp;if&nbsp;`dflt`&nbsp;is&nbsp;not&nbsp;specified.
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                091&nbsp;&nbsp;
+                111&nbsp;&nbsp;
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                092&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;vertex,&nbsp;throws&nbsp;an&nbsp;exception.&quot;
+                112&nbsp;&nbsp;&nbsp;&nbsp;If&nbsp;`o`&nbsp;is&nbsp;not&nbsp;a&nbsp;vertex,&nbsp;throws&nbsp;an&nbsp;exception.&quot;
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                093&nbsp;&nbsp;&nbsp;&nbsp;(memoize
+                113&nbsp;&nbsp;&nbsp;&nbsp;(memoize
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                094&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(fn
+                114&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(fn
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                095&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;([o]
+                115&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;([o]
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                096&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ensure3d&nbsp;o&nbsp;0.0))
+                116&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ensure3d&nbsp;o&nbsp;0.0))
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                097&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;dflt]
+                117&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;([o&nbsp;dflt]
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                098&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
+                118&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(cond
                 </span><br/>
 <span class="partial" title="5 out of 6 forms covered">
-                099&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(not&nbsp;(vertex?&nbsp;o))&nbsp;(throw
+                119&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(not&nbsp;(vertex?&nbsp;o))&nbsp;(throw
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                100&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
+                120&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="not-covered" title="0 out of 13 forms covered">
-                101&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))&nbsp;0&nbsp;80)))
+<span class="not-covered" title="0 out of 12 forms covered">
+                121&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(truncate&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))&nbsp;80)))
                 </span><br/>
 <span class="covered" title="4 out of 4 forms covered">
-                102&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:z&nbsp;o)&nbsp;o
+                122&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(:z&nbsp;o)&nbsp;o
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                103&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else&nbsp;(assoc&nbsp;o&nbsp;:z&nbsp;dflt))))))
+                123&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;:else&nbsp;(assoc&nbsp;o&nbsp;:z&nbsp;dflt))))))
                 </span><br/>
 <span class="blank" title="0 out of 0 forms covered">
-                104&nbsp;&nbsp;
+                124&nbsp;&nbsp;
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                105&nbsp;&nbsp;(def&nbsp;ensure2d
+                125&nbsp;&nbsp;(def&nbsp;ensure2d
                 </span><br/>
 <span class="not-tracked" title="0 out of 0 forms covered">
-                106&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;a&nbsp;vertex,&nbsp;set&nbsp;its&nbsp;`:z`&nbsp;value&nbsp;to&nbsp;zero;&nbsp;else&nbsp;throw&nbsp;an&nbsp;exception.&quot;
+                126&nbsp;&nbsp;&nbsp;&nbsp;&quot;If&nbsp;`o`&nbsp;is&nbsp;a&nbsp;vertex,&nbsp;set&nbsp;its&nbsp;`:z`&nbsp;value&nbsp;to&nbsp;zero;&nbsp;else&nbsp;throw&nbsp;an&nbsp;exception.&quot;
                 </span><br/>
 <span class="covered" title="2 out of 2 forms covered">
-                107&nbsp;&nbsp;&nbsp;&nbsp;(memoize
+                127&nbsp;&nbsp;&nbsp;&nbsp;(memoize
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                108&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(fn&nbsp;[o]
+                128&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(fn&nbsp;[o]
                 </span><br/>
 <span class="covered" title="1 out of 1 forms covered">
-                109&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
+                129&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(if
                 </span><br/>
 <span class="covered" title="3 out of 3 forms covered">
-                110&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;o)
+                130&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(vertex?&nbsp;o)
                 </span><br/>
 <span class="covered" title="5 out of 5 forms covered">
-                111&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;o&nbsp;:z&nbsp;0.0)
+                131&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(assoc&nbsp;o&nbsp;:z&nbsp;0.0)
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                112&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw
+                132&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw
                 </span><br/>
 <span class="not-covered" title="0 out of 1 forms covered">
-                113&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
+                133&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(IllegalArgumentException.
                 </span><br/>
-<span class="not-covered" title="0 out of 13 forms covered">
-                114&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(subs&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))&nbsp;0&nbsp;80)))))))
+<span class="not-covered" title="0 out of 12 forms covered">
+                134&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(truncate&nbsp;(str&nbsp;&quot;Not&nbsp;a&nbsp;vertex:&nbsp;&quot;&nbsp;(or&nbsp;o&nbsp;&quot;nil&quot;))&nbsp;80)))))))
+                </span><br/>
+<span class="blank" title="0 out of 0 forms covered">
+                135&nbsp;&nbsp;
+                </span><br/>
+<span class="covered" title="1 out of 1 forms covered">
+                136&nbsp;&nbsp;(defn&nbsp;within-box?
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                137&nbsp;&nbsp;&nbsp;&nbsp;&quot;True&nbsp;if&nbsp;`target`&nbsp;is&nbsp;within&nbsp;the&nbsp;box&nbsp;defined&nbsp;by&nbsp;`minv`&nbsp;and&nbsp;`maxv`.&nbsp;All
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                138&nbsp;&nbsp;&nbsp;&nbsp;arguments&nbsp;must&nbsp;be&nbsp;vertices;&nbsp;additionally,&nbsp;both&nbsp;`minv`&nbsp;and&nbsp;`maxv`&nbsp;must
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                139&nbsp;&nbsp;&nbsp;&nbsp;have&nbsp;`:z`&nbsp;coordinates.&quot;
+                </span><br/>
+<span class="not-tracked" title="0 out of 0 forms covered">
+                140&nbsp;&nbsp;&nbsp;&nbsp;[target&nbsp;minv&nbsp;maxv]
+                </span><br/>
+<span class="not-covered" title="0 out of 20 forms covered">
+                141&nbsp;&nbsp;&nbsp;&nbsp;(when-not&nbsp;(and&nbsp;(vertex?&nbsp;target)&nbsp;(vertex?&nbsp;minv)&nbsp;(vertex?&nbsp;maxv))
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                142&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(throw&nbsp;(IllegalArgumentException.
+                </span><br/>
+<span class="not-covered" title="0 out of 5 forms covered">
+                143&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(s&#x2F;join&nbsp;&quot;&nbsp;&quot;&nbsp;[&quot;Arguments&nbsp;to&nbsp;`within-box?`&nbsp;must&nbsp;be&nbsp;vertices:&quot;
+                </span><br/>
+<span class="not-covered" title="0 out of 7 forms covered">
+                144&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map&nbsp;kind-type&nbsp;[target&nbsp;minv&nbsp;maxv])]))))
+                </span><br/>
+<span class="not-covered" title="0 out of 2 forms covered">
+                145&nbsp;&nbsp;&nbsp;&nbsp;(every?
+                </span><br/>
+<span class="not-covered" title="0 out of 3 forms covered">
+                146&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(map
+                </span><br/>
+<span class="not-covered" title="0 out of 16 forms covered">
+                147&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;#(&lt;&nbsp;(%&nbsp;minv)&nbsp;(or&nbsp;(%&nbsp;target)&nbsp;0)&nbsp;(%&nbsp;maxv))
+                </span><br/>
+<span class="not-covered" title="0 out of 4 forms covered">
+                148&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[:x&nbsp;:y&nbsp;:z])))
                 </span><br/>
  </body>
 </html>
diff --git a/project.clj b/project.clj
index 348e8ed..2636161 100644
--- a/project.clj
+++ b/project.clj
@@ -31,5 +31,5 @@
                   ["uberjar"]
                   ["change" "version" "leiningen.release/bump-version"]
                   ["vcs" "commit"]]
-  :repl-options {:init-ns walkmap.core}
+  :repl-options {:init-ns walkmap.superstructure}
   :url "https://simon-brooke.github.io/walkmap/")
diff --git a/src/walkmap/routing.clj b/src/walkmap/routing.clj
index b925341..fc35d54 100644
--- a/src/walkmap/routing.clj
+++ b/src/walkmap/routing.clj
@@ -1,4 +1,4 @@
-(ns walkmap.core
+(ns walkmap.routing
   "Finding optimal routes to traverse a map."
     (:require [walkmap.path :as p]
             [walkmap.polygon :as q]
diff --git a/src/walkmap/stl.clj b/src/walkmap/stl.clj
index 864b4ca..892d17f 100644
--- a/src/walkmap/stl.clj
+++ b/src/walkmap/stl.clj
@@ -6,6 +6,7 @@
             [org.clojars.smee.binary.core :as b]
             [taoensso.timbre :as l]
             [walkmap.edge :as e]
+            [walkmap.ocean :as o]
             [walkmap.polygon :refer [centre gradient polygon?]]
             [walkmap.superstructure :refer [store]]
             [walkmap.tag :refer [tag]]
diff --git a/src/walkmap/svg.clj b/src/walkmap/svg.clj
index bbb9d9f..5f14232 100644
--- a/src/walkmap/svg.clj
+++ b/src/walkmap/svg.clj
@@ -108,9 +108,3 @@
        :hiccup (spit out-filename (html s))
        (throw (Exception. "Unexpected renderer value: " *preferred-svg-render*)))
      s)))
-
-
-(defn read-svg
-  ([file-name]
-   (read-svg file-name nil))
-  ([file-name map-kind]
diff --git a/src/walkmap/vertex.clj b/src/walkmap/vertex.clj
index de7c81e..ca894c4 100644
--- a/src/walkmap/vertex.clj
+++ b/src/walkmap/vertex.clj
@@ -6,8 +6,7 @@
   (:require [clojure.math.numeric-tower :as m]
             [clojure.string :as s]
             [taoensso.timbre :as l]
-            [walkmap.geometry :refer [=ish]]
-            [walkmap.utils :refer [kind-type truncate]]))
+            [walkmap.utils :refer [=ish kind-type truncate]]))
 
 (defn vertex-key
   "Making sure we get the same key everytime we key a vertex with the same
diff --git a/test/walkmap/core_test.clj b/test/walkmap/core_test.clj
deleted file mode 100644
index b84b538..0000000
--- a/test/walkmap/core_test.clj
+++ /dev/null
@@ -1,7 +0,0 @@
-(ns walkmap.core-test
-  (:require [clojure.test :refer :all]
-            [walkmap.core :refer :all]))
-
-;; (deftest a-test
-;;   (testing "FIXME, I fail."
-;;     (is (= 0 1))))
diff --git a/test/walkmap/geometry_test.clj b/test/walkmap/utils_test.clj
similarity index 88%
rename from test/walkmap/geometry_test.clj
rename to test/walkmap/utils_test.clj
index 9c7bc4d..3a09b01 100644
--- a/test/walkmap/geometry_test.clj
+++ b/test/walkmap/utils_test.clj
@@ -1,6 +1,6 @@
-(ns walkmap.geometry-test
+(ns walkmap.utils-test
   (:require [clojure.test :refer :all]
-            [walkmap.geometry :refer :all]))
+            [walkmap.utils :refer :all]))
 
 (deftest =ish-tests
   (testing "Rough equality"