proposition: Lemma leI2r_le y t x z : y `|` z = \top -> y `&` x <= t `&` z -> x <= z.
proof: Proof. by rewrite joinC; exact: (@leU2r_le _ L^d). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)