proposition: Lemma deg2_poly_gt0 : reflect (forall x, 0 < p.[x]) (delta < 0).
proof: Proof. by rewrite deltam; apply: deg2_poly_gt0; rewrite // -/a a1 ler01. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)