proposition: Lemma ltr_pMr x y : 0 < y -> (y < y * x) = (1 < x).
proof: Proof. by move=> hy; rewrite -{1}[y]mulr1 ltr_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)