And now the interpreter works (I think) correctly!

src/conspage.c

@@ -73,9 +73,11 @@ void make_cons_page(  ) {
                         strncpy( &cell->tag.bytes[0], TRUETAG, TAGLENGTH );
                         cell->count = MAXREFERENCE;
                         cell->payload.free.car = ( struct cons_pointer ) {
-                        0, 1};
+                            0, 1
+                        };
                         cell->payload.free.cdr = ( struct cons_pointer ) {
-                        0, 1};
+                            0, 1
+                        };
                         fwprintf( stderr, L"Allocated special cell T\n" );
                         break;
                 }
@@ -110,7 +112,8 @@ void dump_pages( FILE * output ) {
 
         for ( int j = 0; j < CONSPAGESIZE; j++ ) {
             dump_object( output, ( struct cons_pointer ) {
-                         i, j} );
+                         i, j
+                         } );
         }
     }
 }

src/consspaceobject.c

@@ -63,7 +63,7 @@ void dec_ref( struct cons_pointer pointer ) {
     }
 }
 
-void dump_string_cell( FILE * output, wchar_t * prefix,
+void dump_string_cell( FILE * output, wchar_t *prefix,
                        struct cons_pointer pointer ) {
     struct cons_space_object cell = pointer2cell( pointer );
     if ( cell.payload.string.character == 0 ) {

src/equal.c

@@ -78,8 +78,8 @@ bool equal( struct cons_pointer a, struct cons_pointer b ) {
                     && ( equal( cell_a->payload.string.cdr,
                                 cell_b->payload.string.cdr )
                          || ( end_of_string( cell_a->payload.string.cdr )
-                              && end_of_string( cell_b->payload.string.
-                                                cdr ) ) );
+                              && end_of_string( cell_b->payload.
+                                                string.cdr ) ) );
                 break;
             case INTEGERTV:
             case REALTV:

src/lispops.c

@@ -128,11 +128,10 @@ eval_lambda( struct cons_space_object cell, struct stack_frame *frame,
     struct cons_pointer new_env = env;
     struct cons_pointer args = cell.payload.lambda.args;
     struct cons_pointer body = cell.payload.lambda.body;
-    struct cons_pointer vals = frame->arg[0];
 
-    while ( consp( args ) && consp( vals ) ) {
+    for ( int i = 0; i < args_in_frame && consp( args ); i++ ) {
         struct cons_pointer arg = c_car( args );
-        struct cons_pointer val = c_car( vals );
+        struct cons_pointer val = frame->arg[i];
         print( stderr, c_string_to_lisp_string( "\n\tBinding " ) );
         print( stderr, arg );
         print( stderr, c_string_to_lisp_string( " to " ) );
@@ -141,8 +140,6 @@ eval_lambda( struct cons_space_object cell, struct stack_frame *frame,
 
         new_env = make_cons( make_cons( arg, val ), new_env );
         args = c_cdr( args );
-        vals = c_cdr( vals );
-
     }
 
     while ( !nilp( body ) ) {
@@ -194,6 +191,8 @@ c_apply( struct stack_frame *frame, struct cons_pointer env ) {
             {
                 struct stack_frame *next =
                     make_stack_frame( frame, args, env );
+                fputws( L"Stack frame for lambda\n", stderr );
+                dump_frame( stderr, next );
                 result = eval_lambda( fn_cell, next, env );
                 free_stack_frame( next );
             }

unit-tests/intepreter.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+expected='6'
+actual=`echo "(apply '(lambda (x y z) (/ (* y z) x)) '(2 3 4))" | target/psse 2> /dev/null | head -2 | tail -1`
+
+if [ "${expected}" = "${actual}" ]
+then
+    echo "OK"
+else
+    echo "Fail: expected '${expected}', got '${actual}'"
+    exit 1
+fi