Section PACO0.
(** ** Signatures *)
Record sig0T  :=
exist0T {
}.
Definition uncurry0  (R: rel0): rel1 sig0T :=
fun x => R.
Definition curry0  (R: rel1 sig0T): rel0 :=
R (@exist0T).

Lemma curry_map0 r0 r1 (LE: r0 <1== r1) : curry0 r0 <0== curry0 r1.