# HG changeset patch
# User blanchet
# Date 1459159547 -7200
# Node ID 3d7fe7ec7981297c546f6169692f81131edc2603
# Parent  f5ee068b96a67aa8693a1c7778fbc4c73dfbafad
strengthened tactic

diff -r f5ee068b96a6 -r 3d7fe7ec7981 src/HOL/Tools/BNF/bnf_gfp_grec_sugar_tactics.ML
--- a/src/HOL/Tools/BNF/bnf_gfp_grec_sugar_tactics.ML	Mon Mar 28 12:05:47 2016 +0200
+++ b/src/HOL/Tools/BNF/bnf_gfp_grec_sugar_tactics.ML	Mon Mar 28 12:05:47 2016 +0200
@@ -69,7 +69,8 @@
     rtac ctxt cong_alg_intro) THEN
   unfold_thms_tac ctxt (extra_simps @ sumprod_thms_rel @
     @{thms vimage2p_def prod.rel_eq sum.rel_eq}) THEN
-  REPEAT_DETERM (HEADGOAL (rtac ctxt conjI ORELSE' assume_tac ctxt ORELSE' rtac ctxt refl));
+  REPEAT_DETERM (HEADGOAL (etac ctxt subst ORELSE' rtac ctxt conjI ORELSE' assume_tac ctxt ORELSE'
+    rtac ctxt refl));
 
 val shared_simps =
   @{thms map_prod_simp map_sum.simps sum.case prod.case_eq_if split_beta' prod.sel