Section CoreDefinitions.
Variable A B : Type.
Implicit Types x y : TVar.
Implicit Types xs ys : list TVar.
Implicit Types v w : A.
Implicit Types vs ws : list A.
Implicit Types E F G : gen_env A.
Implicit Types f g : A -> B.
Definition eq_keys_dec := VarType.eq_dec.
(** Preliminary properties of eq_keys_dec. *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of singulars *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of get *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of dom *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of img *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of map *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of update_one *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of update *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of remove *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of all_remove *)
(* ---------------------------------------------------------------------- *)
(** **** Properties of ok *)
(** Additional properties when ok stands. *)

(** Update commutes with concatenation on the left. *)
Lemma update_one_concat_ok : forall E F x v,
ok (E & F) ->
(E & F) [x <- v] =
(E [x <- v]) & (F [x <- v]).