# HG changeset patch
# User wenzelm
# Date 1438102667 -7200
# Node ID 92913f915e3d5237bcf3fa6d2a494d3d69ef6b22
# Parent  c93a83472eab060df40a6e11c0095c7df6fa421b
clarified context;

diff -r c93a83472eab -r 92913f915e3d src/Pure/Isar/class.ML
--- a/src/Pure/Isar/class.ML	Tue Jul 28 18:57:10 2015 +0200
+++ b/src/Pure/Isar/class.ML	Tue Jul 28 18:57:47 2015 +0200
@@ -748,7 +748,7 @@
 
 fun intro_classes_tac ctxt facts st =
   let
-    val thy = Thm.theory_of_thm st;
+    val thy = Proof_Context.theory_of ctxt;
     val classes = Sign.all_classes thy;
     val class_trivs = map (Thm.class_triv thy) classes;
     val class_intros = map_filter (try (#intro o Axclass.get_info thy)) classes;