From: Enrico Tassi Date: Thu, 6 Jul 2006 09:04:36 +0000 (+0000) Subject: eq_f1 X-Git-Tag: make_still_working~7105 X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=605599ac2037b3632d8c35c7cbc8dda89e04c1bd;p=helm.git eq_f1 --- diff --git a/helm/software/matita/library/logic/equality.ma b/helm/software/matita/library/logic/equality.ma index b87dc6c95..0675edc76 100644 --- a/helm/software/matita/library/logic/equality.ma +++ b/helm/software/matita/library/logic/equality.ma @@ -72,6 +72,11 @@ theorem eq_f: \forall A,B:Type.\forall f:A\to B. intros.elim H.reflexivity. qed. +theorem eq_f1: \forall A,B:Type.\forall f:A\to B. +\forall x,y:A. x=y \to f y = f x. +intros.elim H.reflexivity. +qed. + theorem eq_f2: \forall A,B,C:Type.\forall f:A\to B \to C. \forall x1,x2:A. \forall y1,y2:B. x1=x2 \to y1=y2 \to f x1 y1 = f x2 y2.