proposition: Lemma mulcmE m1 m2 i : mulcm m1 m2 i = (m1 i + m2 i)%N.
proof: Proof. by rewrite cmE fsfun_fun in_fsetE; case: (finsuppP m1); case: (finsuppP m2). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap