proposition: Lemma eq_bigcapr (T U : Type) (A : set T) (F G : T -> set U) : (forall x : T, F x <--> G x) -> \bigcap_(x in A) F x <--> \bigcap_(x in A) G x.
proof: Proof. by move => H a; split; move => Ha b Hb; eapply H; eauto. Qed.
imports: mathcomp.ssreflect.ssreflect Classes.RelationClasses Classes.Morphisms List Tactics mathcomp(ssrfun ssrbool ssrnat seq)