proposition: Lemma mnmwgtM : {morph mnmwgt: m1 m2 / (m1 * m2)%M >-> (m1 + m2)%N}.
proof: Proof. move=> m1 m2 /=; rewrite !mnmwgtE -big_split /=. by apply/eq_bigr=> i _; rewrite cmM mulnDl. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap