proposition: Lemma signr_gt0 (b : bool) : (0 < (-1) ^+ b :> R) = ~~ b.
proof: Proof. by case: b; rewrite (ltr01, ltr0N1). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)