proposition: Lemma polyOverZ : {in S & polyOver S, forall c p, c *: p \is a polyOver S}.
proof: Proof. by move=> c p Sc /polyOverP Sp; apply/polyOverP=> i; rewrite coefZ rpredM ?Sp. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)