proposition: Lemma divr_gt0 x y : 0 < x -> 0 < y -> 0 < x / y.
proof: Proof. by move=> x_gt0 y_gt0; rewrite pmulr_rgt0 ?invr_gt0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)