proposition: Lemma nat_seq_Permutation_cons: forall s i n, i < n -> exists l, Permutation (nat_seq s n) (s + i :: l).
proof: Proof. intros. induction n. 1: lia. replace (S n) with (n + 1) by lia. rewrite nat_seq_app. simpl. destruct (Nat.eq_dec i n). - subst i. exists (nat_seq s n). symmetry. apply Permutation_cons_append. - assert (i < n) by lia. apply IHn in H0. destruct H0 as [l ?]. exists (l +:: (s + n)). rewrite app_comm_cons. apply Permutation_app_tail. 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