Section ExtensionalEquality.
Variables A B C : Type.
Definition eqfun (f g : B -> A) : Prop := forall x, f x = g x.
Definition eqrel (r s : C -> B -> A) : Prop := forall x y, r x y = s x y.

Lemma ftrans f g h : eqfun f g -> eqfun g h -> eqfun f h.