proposition: Lemma ler_nMr x y : y < 0 -> (y <= y * x) = (x <= 1).
proof: Proof. by move=> hy; rewrite -{1}[y]mulr1 ler_nM2l. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)