proposition: Lemma vsa_fold_left: forall (g : LGraph) (gen : nat) (l : list nat) (z1 z2 : Z), fold_left (vertex_size_accum g gen) l (z2 + z1) = fold_left (vertex_size_accum g gen) l z2 + z1.
proof: Proof. intros. revert z1 z2. induction l; intros; simpl. 1: reflexivity. rewrite <- IHl. f_equal. unfold vertex_size_accum. lia. 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