diff -r c5a8b612e571 -r 0040bafffdef src/HOL/Imperative_HOL/Heap.thy
--- a/src/HOL/Imperative_HOL/Heap.thy	Thu Jul 01 16:54:42 2010 +0200
+++ b/src/HOL/Imperative_HOL/Heap.thy	Thu Jul 01 16:54:44 2010 +0200
@@ -18,9 +18,9 @@
 
 instance nat :: heap ..
 
-instance "*" :: (heap, heap) heap ..
+instance prod :: (heap, heap) heap ..
 
-instance "+" :: (heap, heap) heap ..
+instance sum :: (heap, heap) heap ..
 
 instance list :: (heap) heap ..