1 files changed, 2 insertions, 0 deletions

diff --git a/perm.lisp b/perm.lisp
index 01b9271..e1d8c77 100644
--- a/perm.lisp
+++ b/perm.lisp
@@ -1,3 +1,5 @@
+(in-package "ACL2")
+
 (defun perm (x y)
   (cond
     ((atom x) (atom y))