proposition: Lemma no_scan_no_edge: forall g v, no_scan g v -> get_edges g v = nil.
proof: Proof. intros. unfold no_scan in H. apply tag_no_scan in H. unfold get_edges. destruct (filter_sum_right (make_fields g v)) eqn:? . 1: reflexivity. exfalso. assert (In e (filter_sum_right (make_fields g v))) by (rewrite Heql; left; auto). rewrite <- filter_sum_right_In_iff in H0. clear l Heql. apply H. clear H. unfold make_fields in H0. remember (raw_fields (vlabel g v)). clear Heql. remember O. clear Heqn. revert n H0. induction l; simpl; intros; auto. destruct a; [destruct s|]; simpl in H0; [right; destruct H0; [inversion H | eapply IHl; eauto]..|left]; auto. Qed.
imports: Coq.ZArith.ZArith Coq.Program.Basics Coq.micromega.Lia 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 VST.zlist.list_solver CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.graph.graph_model CertiGraph.graph.graph_gen