1 files changed, 1 insertions, 1 deletions
diff --git a/liblali.c b/liblali.c
index 9afec71..a6426af 100644
--- a/liblali.c
+++ b/liblali.c
@@ -1502,7 +1502,7 @@ static char *stdlib = LISP(
   (defun consp (x) (and (listp x) (ap x)))
 
   (defun differ (x y)
-    (fill ((or (consp x) (consp y)) (dif x y))
+    (fill ((and (consp x) (consp y)) (dif x y))
           (f (or (differ (car x) (car y))
                  (differ (cdr x) (cdr y))))))