proposition: Lemma mcoeffZ c g k : (c *: g)@_k = c * g@_k.
proof: Proof. exact/fgscaleE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap