src/Pure/Isar/code_unit.ML

--- a/src/Pure/Isar/code_unit.ML	Thu Apr 10 16:15:53 2008 +0200
+++ b/src/Pure/Isar/code_unit.ML	Thu Apr 10 17:01:37 2008 +0200
@@ -216,7 +216,7 @@
   type T = ((string * string) * thm) list;
   val empty = [];
   val copy = I;
-  val extend = copy;
+  val extend = I;
   fun merge _ = Library.merge (eq_snd Thm.eq_thm_prop);
 );