diff -r 9fb7661651ad -r 442b09c0f898 src/HOL/TLA/Memory/MemoryImplementation.thy
--- a/src/HOL/TLA/Memory/MemoryImplementation.thy	Fri Mar 27 11:38:26 2015 +0100
+++ b/src/HOL/TLA/Memory/MemoryImplementation.thy	Fri Mar 27 17:46:08 2015 +0100
@@ -798,7 +798,7 @@
 fun split_idle_tac ctxt =
   SELECT_GOAL
    (TRY (rtac @{thm actionI} 1) THEN
-    Induct_Tacs.case_tac ctxt "(s,t) |= unchanged (e p, c p, r p, m p, rmhist!p)" [] 1 THEN
+    Induct_Tacs.case_tac ctxt "(s,t) |= unchanged (e p, c p, r p, m p, rmhist!p)" [] NONE 1 THEN
     rewrite_goals_tac ctxt @{thms action_rews} THEN
     forward_tac ctxt [temp_use ctxt @{thm Step1_4_7}] 1 THEN
     asm_full_simp_tac ctxt 1);