proposition: Lemma pcv_is_partial_graph: forall (g: LGraph) old new, sound_gc_graph g -> ~ vvalid g new -> is_partial_graph g (pregraph_copy_v g old new).
proof: Proof. intros. destruct H as [? [? [? Hels]]]. red in H, H1, H2. split; [|split; [|split]]; intros. - rewrite pcv_vvalid_iff. now left. - rewrite pcv_evalid_iff. now left. - rewrite pcv_src_old; auto. intro. now rewrite H2, H5 in H4. - rewrite pcv_dst_old; auto. rewrite H1 in H3. destruct H3. rewrite <- H in H3. intro. now rewrite H6 in H3. 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