proposition: Lemma rootM p q x : root (p * q) x = root p x || root q x.
proof: Proof. by rewrite !rootE hornerM mulf_eq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)