proposition: Lemma eq_meetl x y : (x `&` y == x) = (x <= y).
proof: Proof. by apply/esym/leEmeet. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)