proposition: Lemma mark_marked_reachable_conflict: forall m1 root m2 n (R_DEC: ReachDecidable g root (negateP m1)), mark m1 root m2 -> Included (reachable_by g n (negateP m2)) (Complement _ (reachable_by g root (negateP m1))).
proof: Proof. intros. intro n'; unfold Ensembles.In; intros. eapply mark_reverse_unmarked_strong in H0; [| eauto | eauto]. apply reachable_by_is_reachable in H0. rewrite <- reachable_by_eq_partialgraph_reachable in H0. apply reachable_by_foot_prop in H0. auto. Qed.
imports: Coq.Logic.ProofIrrelevance CertiGraph.lib.Ensembles_ext Coq.Lists.List Coq.Classes.Morphisms CertiGraph.lib.Coqlib CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext VST.msl.Coqlib2 CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.reachable_computable CertiGraph.graph.reachable_ind CertiGraph.graph.graph_gen CertiGraph.graph.graph_relation CertiGraph.graph.subgraph2