Section PACO1.
Variable T0 : Type.
(** ** Signatures *)
Record sig1T  :=
exist1T {
proj1T0: @T0;
}.
Definition uncurry1  (R: rel1 T0): rel1 sig1T :=
fun x => R (proj1T0 x).
Definition curry1  (R: rel1 sig1T): rel1 T0 :=
fun x0 => R (@exist1T x0).

Lemma uncurry_bij1_1 r : curry1 (uncurry1 r) <1== r.