(* This file is copied from RamifyCoq project. *)
Require Coq.Setoids.Setoid.
Require Export Coq.Classes.Equivalence.
Require Export Coq.Sets.Ensembles.
intros.
split; intros [].
Qed.

Lemma Intersection_Complement: forall A (P Q: Ensemble A),
Same_set A
(Intersection A (Complement A P) (Complement A Q))
(Complement A (Union A P Q)).