fact: Definition agreeC (x a a' b b':Set) (f:a->b) (f':a'-> b') (Ha: sub x a)(Hb: sub x a') := forall u:x, Ro(restrictionC f Ha u) = Ro(restrictionC f' Hb u).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)