proposition: Lemma meetUl : left_distributive (meet : T -> T -> T) join.
proof: Proof. by move=> x y z; rewrite /meet /join /= !f'_can meetUl. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)