proposition: Lemma rootN p x : root (- p) x = root p x.
proof: Proof. by rewrite rootE hornerN oppr_eq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)