proposition: Lemma _bcount_empty : _BagCountEmpty.
proof: Proof. unfold _BagCountEmpty, _bcount; intros. rewrite benumerate_empty_eq_nil; simpl; trivial. Qed.
imports: Coq.Arith.Arith Fiat.QueryStructure.Implementation.DataStructures.Bags.BagsInterface Fiat.Common.List.ListFacts Fiat.Common.List.ListMorphisms