proposition: Lemma invr_ge0 x : (0 <= x^-1) = (0 <= x).
proof: Proof. by rewrite !le0r invr_gt0 invr_eq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)