proposition: Lemma deg2_poly_le0l x : x <= r1 -> p.[x] <= 0.
proof: Proof. by move=> ?; rewrite -oppr_ge0 -hornerN deg2_poly_ge0l// deltaN r1N. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)