proposition: Lemma deg2_poly_noroot : reflect (forall x, ~~ root p x) (delta < 0).
proof: Proof. by rewrite deltam; apply: deg2_poly_noroot. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)