proposition: Lemma finset_cardinal_max: forall x, (finset_cardinal x <= IdentSet.cardinal U)%nat.
proof: Proof. intros. apply ISProp.subset_cardinal. apply proj2_sig. Qed.
imports: Coq(ZArith Psatz Bool String Program.Equality FSets Wellfounded) CDF(Sequences IMP Simulation) CDF(Fixpoints)