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

Theorem binds_map_inv : forall A B x (w : B) (E : gen_env A) (f : A -> B),
x ∹ w ⋲ (map f E) ->
exists v, x ∹ v ⋲ E /\ w = f v.