proposition: Lemma ger_pMr x y : 0 < y -> (y * x <= y) = (x <= 1).
proof: Proof. by move=> hy; rewrite -{2}[y]mulr1 ler_pM2l. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)