proposition: Lemma cmE_eq0 m i : (m i == 0%N) = (i \notin finsupp m).
proof: Proof. by rewrite memNfinsupp. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap