proposition: Lemma pmulrn_rlt0 x n : 0 < x -> x *+ n < 0 = false.
proof: Proof. by move=> x_gt0; rewrite -(mulr0n x) ltr_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)