X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fsoftware%2Fmatita%2Flibrary%2Flogic%2Fequality.ma;h=3b242c66709d6562debbc465a00e930cd4fb370e;hb=894c3e4038c93b484896e81132eae55046e47605;hp=95cb973074df0794ff8bd0003b357e965a2ef866;hpb=b273fb8dacc8ce058ffa4677846085864ace6b36;p=helm.git diff --git a/helm/software/matita/library/logic/equality.ma b/helm/software/matita/library/logic/equality.ma index 95cb97307..3b242c667 100644 --- a/helm/software/matita/library/logic/equality.ma +++ b/helm/software/matita/library/logic/equality.ma @@ -60,6 +60,21 @@ theorem eq_elim_r: intros. elim (sym_eq ? ? ? H1).assumption. qed. +theorem eq_f: \forall A,B:Type.\forall f:A\to B. +\forall x,y:A. x=y \to f x = f y. +intros.elim H.apply refl_eq. +qed. + +theorem eq_f': \forall A,B:Type.\forall f:A\to B. +\forall x,y:A. x=y \to f y = f x. +intros.elim H.apply refl_eq. +qed. + +(* +coercion cic:/matita/logic/equality/sym_eq.con. +coercion cic:/matita/logic/equality/eq_f.con. +*) + default "equality" cic:/matita/logic/equality/eq.ind cic:/matita/logic/equality/sym_eq.con @@ -67,19 +82,8 @@ default "equality" cic:/matita/logic/equality/eq_ind.con cic:/matita/logic/equality/eq_elim_r.con cic:/matita/logic/equality/eq_f.con - cic:/matita/logic/equality/eq_OF_eq.con. (* \x.sym (eq_f x) *) - + cic:/matita/logic/equality/eq_f'.con. (* \x.sym (eq_f x) *) -theorem eq_f: \forall A,B:Type.\forall f:A\to B. -\forall x,y:A. x=y \to f x = f y. -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.