proposition: Lemma pmulr_rge0 x y : 0 < x -> (0 <= x * y) = (0 <= y).
proof: Proof. by move=> x_gt0; rewrite !le0r mulf_eq0 pmulr_rgt0 // gt_eqF. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)