diff -r 738598beeb26 -r 118f7cb0ee8e src/HOL/Bali/DefiniteAssignmentCorrect.thy
--- a/src/HOL/Bali/DefiniteAssignmentCorrect.thy	Tue Mar 26 20:02:02 2013 +0100
+++ b/src/HOL/Bali/DefiniteAssignmentCorrect.thy	Tue Mar 26 20:36:32 2013 +0100
@@ -3046,7 +3046,7 @@
             by auto
           with nrm_C_C' nrm_C' A
           have "?NormalAssigned s3 A"
-            by fastforce
+            by auto
           moreover
           from eq_s3_s2 brk_C_C' brk_C' normal_s1 A
           have "?BreakAssigned (Norm s0) s3 A"