--- a/src/Pure/Isar/calculation.ML Sat Sep 04 21:05:01 1999 +0200
+++ b/src/Pure/Isar/calculation.ML Sat Sep 04 21:05:25 1999 +0200
@@ -125,8 +125,7 @@
val facts = Proof.the_facts state;
val rules = Seq.of_list (if_none opt_rules [] @ get_local_rules state);
- fun differ thms thms' =
- length thms <> length thms' orelse exists2 (not o Thm.eq_thm) (thms, thms');
+ fun differ thms thms' = not (Library.equal_lists Thm.eq_thm (thms, thms'));
fun combine thms =
Seq.map Library.single (Seq.flat (Seq.map (Method.multi_resolve (thms @ facts)) rules));