proposition: Lemma Included_Complement_Disjoint: forall A P Q, (Included P (Complement _ Q)) <-> Disjoint A P Q.
proof: Proof. intros. unfold Included, Complement, In. rewrite Disjoint_spec. firstorder. Qed.
imports: Coq.Classes.Morphisms Coq.Classes.Equivalence Coq.Sets.Ensembles Coq.Sets.Constructive_sets CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext