Section maps'.
Variable A B : Setoid'.
Definition Map_law' (f : A -> B) := forall x y : A, x =_S' y -> f x =_S' f y.
Structure > Map' : Type :=  {Ap' :> A -> B; Pres' :> Map_law' Ap'}.
(*** rewrite rule ***)
(* *)
Definition Ext' (f g : Map') := forall x : A, f x =_S' g x.

Lemma Ext_equiv' : Equivalence Ext'.