proposition: Lemma monic_comreg p : p \is monic -> GRing.comm p (lead_coef p)%:P /\ GRing.rreg (lead_coef p).
proof: Proof. by move/monicP->; split; [apply: commr1 | apply: rreg1]. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype bigop finset tuple) mathcomp(div ssralg countalg binomial)