proposition: Lemma ltr_wMn2r x y n : x < y -> (x *+ n < y *+ n) = (0 < n)%N.
proof: Proof. by move=> ltxy; case: n=> // n; rewrite 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)