proposition: Lemma rdivpK p : rdvdp d p -> rdivp p d * d = p * (lead_coef d ^+ rscalp p d)%:P.
proof: Proof. by rewrite rdivp_eq /rdvdp; move/eqP->; rewrite addr0. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop ssralg poly)