--- a/ac.scm	2009-11-01 14:02:06.000000000 -0500
+++ b/ac.scm	2009-11-01 14:02:42.000000000 -0500
@@ -34,7 +34,7 @@
          (ac (list 'no (cons (cadar s) (cdr s))) env))
         ((eq? (xcar (xcar s)) 'andf) (ac-andf s env))
         ((pair? s) (ac-call (car s) (cdr s) env))
-        (#t (err "Bad object in expression" s))))
+        (#t s)))
 
 (define atstrings #f)