proposition: Lemma setICA A B C : A :&: (B :&: C) = B :&: (A :&: C).
proof: Proof. by rewrite !setIA (setIC A). Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop)