proposition: Lemma incl_bigcup_compat : forall (T U : Type) (A B : set T) (F G : T -> set U), A \subset B -> (forall x : T, F x \subset G x) -> \bigcup_(x in A) F x \subset \bigcup_(x in B) G x.
proof: Proof. now firstorder. Qed.
imports: mathcomp.ssreflect.ssreflect Classes.RelationClasses Classes.Morphisms List Tactics mathcomp(ssrfun ssrbool ssrnat seq)