proposition: Lemma NoDup_one: forall A (n: A), NoDup (n :: nil).
proof: Proof. intros. apply NoDup_cons. inversion 1. apply NoDup_nil. 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