proposition: Lemma ltrMn2r n x y : (x *+ n < y *+ n) = ((0 < n)%N && (x < y)).
proof: Proof. by case: n => [|n]; rewrite ?lexx ?eqxx // ltr_pMn2r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)