proposition: Lemma mulrz_sumr : forall x I r (P : pred I) F, x *~ (\sum_(i <- r | P i) F i) = \sum_(i <- r | P i) x *~ F i.
proof: Proof. by rewrite -/M^z; apply: scaler_suml. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)