diff -r 421f8bc19ce4 -r 2814ff2a6e3e src/HOL/Bali/DefiniteAssignment.thy
--- a/src/HOL/Bali/DefiniteAssignment.thy	Sun Jul 31 11:13:38 2011 -0700
+++ b/src/HOL/Bali/DefiniteAssignment.thy	Mon Aug 01 12:08:53 2011 +0200
@@ -1056,8 +1056,7 @@
        (is "PROP ?Hyp Env B t A")  
   proof (induct)
     case Skip 
-    from Skip.prems Skip.hyps 
-    show ?case by cases simp
+    then show ?case by cases simp
   next
     case Expr 
     from Expr.prems Expr.hyps