proposition: Lemma weak_valid_si: forall (g1 g2: Graph) n, g1 ~=~ g2 -> (weak_valid g1 n <-> weak_valid g2 n).
proof: Proof. intros. unfold weak_valid. destruct H as [? _]. rewrite H. reflexivity. Qed.
imports: CertiGraph.lib.Ensembles_ext Coq.Lists.List VST.msl.seplog VST.msl.log_normalize CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext CertiGraph.msl_ext.log_normalize CertiGraph.msl_ext.iter_sepcon CertiGraph.msl_ext.seplog CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.reachable_computable CertiGraph.graph.reachable_ind CertiGraph.graph.subgraph2 CertiGraph.graph.graph_gen CertiGraph.graph.BinGraph CertiGraph.graph.MathGraph CertiGraph.graph.FiniteGraph CertiGraph.msl_application.Graph Coq.Logic.Classical