diff -r 1af327306c8e -r 4e7307e229b3 src/Pure/subgoal.ML
--- a/src/Pure/subgoal.ML	Thu Nov 30 14:17:29 2006 +0100
+++ b/src/Pure/subgoal.ML	Thu Nov 30 14:17:29 2006 +0100
@@ -29,7 +29,8 @@
 
 fun focus ctxt i st =
   let
-    val ((schematics, [st']), ctxt') = Variable.import true [norm_hhf st] ctxt;
+    val ((schematics, [st']), ctxt') =
+      Variable.import true [MetaSimplifier.norm_hhf_protect st] ctxt;
     val ((params, goal), ctxt'') = Variable.focus_subgoal i st' ctxt';
     val asms = Drule.strip_imp_prems goal;
     val concl = Drule.strip_imp_concl goal;