proposition: Lemma fl_graph_has_gen: forall from to depth l g g', graph_has_gen g to -> forward_loop from to depth l g g' -> forall x, graph_has_gen g x <-> graph_has_gen g' x.
proof: Proof. intros. revert g g' H H0 x. induction l; intros; inversion H0. 1: reflexivity. subst. assert (forall y, graph_has_gen g y <-> graph_has_gen g2 y) by (intros; apply (fr_graph_has_gen _ _ _ _ _ _ H H4)). transitivity (graph_has_gen g2 x). 1: apply H1. rewrite H1 in H. apply IHl; assumption. 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