# HG changeset patch # User paulson # Date 1112699120 -7200 # Node ID 157f3988f7752bf325e6bc67b202f28aa3dcb5ef # Parent d53e5370cfbfc3bc5c541afafeb8554c576ca167 arg_cong2 by Norbert Voelker diff -r d53e5370cfbf -r 157f3988f775 src/HOL/HOL.thy --- a/src/HOL/HOL.thy Tue Apr 05 08:03:52 2005 +0200 +++ b/src/HOL/HOL.thy Tue Apr 05 13:05:20 2005 +0200 @@ -270,6 +270,12 @@ apply (rule refl) done +lemma arg_cong2: "\ a = b; c = d \ \ f a c = f b d" +apply (erule ssubst)+ +apply (rule refl) +done + + lemma cong: "[| f = g; (x::'a) = y |] ==> f(x) = g(y)" apply (erule subst)+ apply (rule refl)