Mainly unit tests. 39/45 currently pass; the failures are all in bignum arithmetic and in deallocation.

unit-tests/let.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+result=0
+
 expected='11'
 actual=`echo "(let ((a . 5)(b . 6)) (+ a b))" | target/psse | tail -1`
 
@@ -8,7 +10,7 @@ then
     echo "OK"
 else
     echo "Fail: expected '$expected', got '$actual'"
-    exit 1
+    result=1
 fi
 
 expected='1'
@@ -17,8 +19,9 @@ actual=`echo "(let ((a . 5)(b . 6)) (+ a b) (- b a))" | target/psse | tail -1`
 if [ "${expected}" = "${actual}" ]
 then
     echo "OK"
-    exit 0
 else
     echo "Fail: expected '$expected', got '$actual'"
-    exit 1
+    result=1
 fi
+
+exit ${result}