proposition: Lemma mcoeffCM c g k : (c%:MP * g)@_k = c * g@_k :> R.
proof: Proof. by rewrite mul_malgC mcoeffZ. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap