proposition: Lemma inter_subset_2b : forall s s', subset (inter s s') s'.
proof: Proof. to_caps; auto with sets. Qed.
imports: Coq.MSets.MSetInterface Coq.MSets.MSetProperties Coq.MSets.MSetFacts Coq.MSets.MSetDecide Fiat.Common.Instances Fiat.Common.BoolFacts Fiat.Common