--- a/src/HOL/ex/Execute_Choice.thy Mon Sep 13 08:43:48 2010 +0200
+++ b/src/HOL/ex/Execute_Choice.thy Mon Sep 13 11:13:15 2010 +0200
@@ -26,7 +26,7 @@
case True then show ?thesis by (simp add: is_empty_def keys_def valuesum_def)
next
case False
- then have l: "\<exists>l. l \<in> dom (Mapping.lookup m)" by (auto simp add: is_empty_def ext_iff mem_def keys_def)
+ then have l: "\<exists>l. l \<in> dom (Mapping.lookup m)" by (auto simp add: is_empty_def fun_eq_iff mem_def keys_def)
then have "(let l = SOME l. l \<in> dom (Mapping.lookup m) in
the (Mapping.lookup m l) + (\<Sum>k \<in> dom (Mapping.lookup m) - {l}. the (Mapping.lookup m k))) =
(\<Sum>k \<in> dom (Mapping.lookup m). the (Mapping.lookup m k))"