diff -r 5c5b5c7f1157 -r a9873318fe30 src/HOL/Tools/inductive.ML
--- a/src/HOL/Tools/inductive.ML	Fri Apr 30 17:18:29 2010 +0200
+++ b/src/HOL/Tools/inductive.ML	Fri Apr 30 18:06:29 2010 +0200
@@ -446,7 +446,7 @@
     val cprop = Thm.cterm_of thy prop;
     val tac = ALLGOALS (simp_case_tac ss) THEN prune_params_tac;
     fun mk_elim rl =
-      Thm.implies_intr cprop (Tactic.rule_by_tactic tac (Thm.assume cprop RS rl))
+      Thm.implies_intr cprop (Tactic.rule_by_tactic ctxt tac (Thm.assume cprop RS rl))
       |> singleton (Variable.export (Variable.auto_fixes prop ctxt) ctxt);
   in
     (case get_first (try mk_elim) elims of