(* 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.
Arguments Included {U} B C.
Arguments Same_set {U} B C.

Lemma Intersection_assoc: forall A P Q R, Same_set (Intersection A (Intersection A P Q) R) (Intersection A P (Intersection A Q R)).