Section SubMemLaws.
Variable T : Type.
End ListMembership.
Prenex Implicits Mem_map_inv.
(* Setoids for extensional equality of functions *)

Lemma eqfun_refl A B (f : A -> B) : f =1 f. Proof. by []. Qed.
Lemma eqfun_sym A B (f1 f2 : A -> B) : f1 =1 f2 -> f2 =1 f1.