proposition: Lemma pcv_evalid_iff: forall g v new e, evalid (pregraph_copy_v g v new) e <-> evalid g e \/ In e (map (fun x => (new, snd x)) (get_edges g v)).
proof: Proof. intros. unfold pregraph_copy_v. rewrite cvae_evalid_iff. rewrite map_fst_combine. - replace (length (get_edges g v)) with (length (map snd (get_edges g v))) by (rewrite map_length; reflexivity). rewrite combine_repeat_eq_map, map_map. reflexivity. - unfold EType at 1. rewrite combine_length, repeat_length, !map_length. apply Nat.min_id. Qed.
imports: Coq.ZArith.ZArith Coq.Program.Basics compcert.lib.Integers compcert.common.Values VST.veric.base VST.veric.Clight_lemmas VST.veric.val_lemmas VST.veric.shares VST.msl.seplog VST.msl.shares VST.zlist.sublist VST.floyd.coqlib3 VST.floyd.functional_base VST.floyd.data_at_rec_lemmas CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.graph.graph_model CertiGraph.graph.graph_gen CertiGraph.graph.path_lemmas CertiGraph.graph.subgraph2 CertiGraph.graph.graph_relation CertiGraph.graph.graph_isomorphism CertiGraph.graph.reachable_ind CertiGraph.CertiGC.GCGraph