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

Theorem all_belongs_all_binds : forall A xs (F : gen_env A),
xs ⊂ F ->
exists vs, (xs ∷ vs) ⊏ F.