Section Properties.
Implicit Types x y : TVar.
Implicit Types xs ys : list TVar.
(* ---------------------------------------------------------------------- *)
(** **** Abstract properties of ok *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of binds *)

Theorem binds_all_remove : forall A x ys (v : A) (E : gen_env A),
¬ List.In x ys -> x ∹ v ⋲ E ->
x ∹ v ⋲ (E ∖ ys).