diff --git a/src/lisp/drawl.pla b/src/lisp/drawl.pla
index 7c1a0f1..732b227 100644
--- a/src/lisp/drawl.pla
+++ b/src/lisp/drawl.pla
@@ -544,8 +544,18 @@ def eval_pred(bool)
   return bool ?? @pred_true :: @pred_false
 end
 
-def natv_atom(atom)
-  return eval_pred(!atom or atom->type <> CONS_TYPE)
+def natv_atom(expr)
+  var result
+
+  result = eval_expr(expr=>car)
+  return eval_pred(!result or result->type <> CONS_TYPE))
+end
+
+def natv_null(expr)
+  var result
+
+  result = eval_expr(expr=>car)
+  return eval_pred(!result or !result->type)
 end
 
 def natv_eq(expr)
@@ -601,13 +611,6 @@ def natv_cond(expr)
   return NULL
 end
 
-def natv_null(expr)
-  var result
-
-  result = eval_expr(expr=>car)
-  return eval_pred(!result or !result->type)
-end
-
 def natv_label(expr)
   var valptr
 
diff --git a/src/lisp/maplist.lisp b/src/lisp/maplist.lisp
new file mode 100644
index 0000000..149df07
--- /dev/null
+++ b/src/lisp/maplist.lisp
@@ -0,0 +1,15 @@
+(define
+  (ydot
+    (lambda (x y)
+      (maplist x '(lambda (j) (cons (car j) y)))
+    )
+  )
+  (maplist
+    (lambda (l fn)
+      (cond
+        ((null l) nil)
+        (T (cons (fn l) (maplist (cdr l) fn)))
+      )
+    )
+  )
+)
diff --git a/src/lisp/set.lisp b/src/lisp/set.lisp
index 43f70ec..9f4b865 100644
--- a/src/lisp/set.lisp
+++ b/src/lisp/set.lisp
@@ -1,4 +1,14 @@
 (define
+  (equal (lambda (x y)
+    (cond ((atom x) (cond ((atom y) (eq x y))
+                           ( t f)
+                      )
+          )
+          ((equal (car x) (car y)) (equal (cdr x) (cdr y)))
+          ( t f)
+    ))
+  )
+
   (member (lambda (a x)
     (cond ((null x) f)
           ((eq a (car x)) t)
diff --git a/src/mklisp b/src/mklisp
index 89c7156..96549bc 100755
--- a/src/mklisp
+++ b/src/mklisp
@@ -3,3 +3,4 @@ cp ../sysfiles/BLANK140.po PLASMA-2.1-LISP.po
 cat rel/DRAWL#FE1000  | ./ac.jar -p   PLASMA-2.1-LISP.po DRAWL REL
 cat lisp/drawl.pla    | ./ac.jar -ptx PLASMA-2.1-LISP.po DRAWL.PLA TXT
 cat lisp/set.lisp     | ./ac.jar -ptx PLASMA-2.1-LISP.po SET.LISP TXT
+cat lisp/maplist.lisp | ./ac.jar -ptx PLASMA-2.1-LISP.po MAPLIST.LISP TXT
diff --git a/src/mkrel b/src/mkrel
index e4e6e44..6e876e7 100755
--- a/src/mkrel
+++ b/src/mkrel
@@ -177,6 +177,7 @@ mkdir prodos/bld/lisp
 cp rel/DRAWL#FE1000       prodos/bld/lisp/DRAWL.REL
 cp lisp/drawl.pla         prodos/bld/lisp/DRAWL.PLA.TXT
 cp lisp/set.lisp          prodos/bld/lisp/SET.LISP.TXT
+cp lisp/maplist.lisp      prodos/bld/lisp/MAPLIST.LISP.TXT
 
 #mkdir prodos/bld/examples
 #cp samplesrc/examples/ex.1.pla  prodos/bld/examples/EX.1.PLA.TXT