proposition: Lemma ltr_pMn2l x : 0 < x -> {mono (@GRing.natmul R x) : m n / (m < n)%N >-> m < n}.
proof: Proof. by move=> x_gt0; apply: leW_mono (ler_pMn2l _). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)