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