diff --git a/lib/simple-utils.lisp b/lib/simple-utils.lisp
index ee64f56..370fd3d 100755
--- a/lib/simple-utils.lisp
+++ b/lib/simple-utils.lisp
@@ -6,20 +6,15 @@
 (defun single (lst)
   (and (consp lst) (not (cdr lst))))
 
-(defun mapa-b (fn a b &optional (step 1))
-  "Maps function over integers from a to b"
-  (do ((i a (+ i step))
-       (result nil))
-      ((> i b) (nreverse result))
-    (push (funcall fn i) result)))
-
 (defun map0-n (fn n)
   "maps from 0 to n"
-  (mapa-b fn 0 n))
+  (loop for x from 0 to n
+       collect (funcall fn x)))
 
 (defun map1-n (fn n)
   "maps from 1 to n"
-  (mapa-b fn 1 n))
+  (loop for x from 1 to n
+     collect (funcall fn x)))
 
 (defmacro mac (expr)
   `(pprint (macroexpand-1 ',expr)))