proposition: Lemma redivpP m d : redivp_spec m d (redivp m d).
proof: Proof. rewrite redivp_def; constructor; last by move=> dn0; rewrite ltn_rmodp. by rewrite -mul_polyC mulrC rdivp_eq //= /GRing.comm mulrC. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop ssralg poly)