proposition: Lemma deg2_poly_lt0m x : r1 < x < r2 -> p.[x] < 0.
proof: Proof. by move=> ?; apply: deg2_poly_lt0m; rewrite // -/a ?a1 ?ler01 ?mulr1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)