proposition: Lemma remove_In_iff: forall (A : Type) (eq_dec : forall x y : A, {x = y} + {x <> y}) (l : list A) (x y : A), In x (remove eq_dec y l) <-> In x l /\ x <> y.
proof: Proof. intros. induction l; simpl. 1: tauto. destruct (eq_dec y a); [subst | simpl ]; rewrite IHl; intuition. apply n. subst; auto. 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