proposition: Lemma disj_le x y : x `&` y == \bot -> x <= y = (x == \bot).
proof: Proof. by rewrite [x == \bot]eq_sym -eq_meetl => /eqP ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)