From c1a9b6977ae0d7aec12816da1ff73862ce7763d6 Mon Sep 17 00:00:00 2001
From: Gerd Heber <gheber@hdfgroup.org>
Date: Wed, 15 Jul 2015 18:45:51 -0500
Subject: [PATCH] CCL can't initialize the INTR slot with NIL.

---
 src/classes.lisp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/classes.lisp b/src/classes.lisp
index 5317d9c..4f3731f 100644
--- a/src/classes.lisp
+++ b/src/classes.lisp
@@ -85,7 +85,7 @@
 ;; (function (degr) (list gnrt))
 
 ;; INTR-MRPH = INTeRnal-MoRPHism
-(DEFTYPE INTR-MRPH () '(or function morphism))
+(DEFTYPE INTR-MRPH () '(or function morphism +ccl null))
 ;; (or (function (degr gnrt) cmbn)  ;; if :gnrt strategy
 ;;     (function (cmbn) (cmbn))     ;; if :cmbn strategy