proposition: Lemma rootE p x : (root p x = (p.[x] == 0)) * ((x \in root p) = (p.[x] == 0)).
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)