proposition: Lemma polyOver0 S : 0 \is a polyOver S.
proof: Proof. by rewrite qualifE /= polyseq0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)