proposition: Lemma coeffZ c D x : coeff x (c *: D) = c * coeff x D.
proof: Proof. by rewrite coeff_fgscale. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order generic_quotient) mathcomp(ssralg ssrnum ssrint)