proposition: Lemma ltr_pMl x y : 0 < y -> (y < x * y) = (1 < x).
proof: Proof. by move=> hy; rewrite -{1}[y]mul1r ltr_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)