proposition: Lemma copy_and_extended_copy: forall g1 g1' g2 g2' g2'' x0, copy x0 g1 g2 g2'' -> extended_copy x0 (g1, g1') (g2, g2') -> Prop_join (vvalid g1') (vvalid g2'') (vvalid g2').
proof: Proof. intros. destruct H as [_ [_ ?]]. destruct H0 as [_ [_ ?]]. destruct H as [_ [_ [_ [? [? _]]]]]. destruct H0 as [_ [_ [_ [? _]]]]. destruct H0 as [? [? _]]. rewrite <- H in H0. rewrite <- H1 in H2. auto. Qed.
imports: VST.msl.seplog VST.msl.log_normalize CertiGraph.lib.Coqlib CertiGraph.lib.Ensembles_ext CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.lib.relation_list CertiGraph.lib.Morphisms_ext CertiGraph.msl_ext.log_normalize CertiGraph.msl_ext.iter_sepcon CertiGraph.msl_ext.ramification_lemmas 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 CertiGraph.graph.dag CertiGraph.graph.weak_mark_lemmas CertiGraph.graph.graph_morphism CertiGraph.graph.local_graph_copy CertiGraph.msl_application.Graph Coq.Logic.Classical