src/HOL/Set.ML
changeset 5318 72bf8039b53f
parent 5316 7a8975451a89
child 5336 721bf1a13f1a
--- a/src/HOL/Set.ML	Fri Aug 14 12:02:35 1998 +0200
+++ b/src/HOL/Set.ML	Fri Aug 14 12:03:01 1998 +0200
@@ -170,7 +170,7 @@
 
 (*Anti-symmetry of the subset relation*)
 Goal "[| A <= B;  B <= A |] ==> A = (B::'a set)";
-br set_ext 1;
+by (rtac set_ext 1);
 by (blast_tac (claset() addIs [subsetD]) 1);
 qed "subset_antisym";
 val equalityI = subset_antisym;