proposition: Lemma ger_pMl x y : 0 < y -> (x * y <= y) = (x <= 1).
proof: Proof. by move=> hy; rewrite -{2}[y]mul1r ler_pM2r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)