proposition: Lemma remove_len_le: forall (A : Type) (eq_dec : forall x y : A, {x = y} + {x <> y}) (l : list A) (x : A), length (remove eq_dec x l) <= length l.
proof: Proof. induction l; intros; simpl in *. auto. destruct (eq_dec x a). intuition. simpl. intuition. 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