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

(** Binds and empty. *)
Theorem binds_empty : forall A x (v : A),
x ∹ v ⋲ (@empty A) ->
False.