proposition: Lemma mark_marked: forall (g1: Graph) root (g2: Graph), mark g1 root g2 -> ReachDecidable g1 root (unmarked g1) -> forall n, marked g1 n -> marked g2 n.
proof: Proof. intros. rewrite mark_inj in H. destruct H. apply @SIMPLE_MARK_GRAPH.mark_markeds with (n := n) in H1; 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