proposition: Lemma eq_as_set_nil: forall {A} (l : list A), nil ~= l -> l = nil.
proof: Proof. intros; destruct l; auto. destruct H. assert (In a (a :: l)) by apply in_eq. specialize (H0 a H1). inversion H0. Qed.
imports: Coq.Lists.List Coq.micromega.Lia Coq.Sorting.Permutation Coq.ZArith.ZArith_base Coq.ZArith.Zcomplements Coq.Logic.FunctionalExtensionality CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext VST.zlist.sublist VST.zlist.list_solver