Section pb1_diese_def.
Variables (r : C) (t1 : r --> G P1) (t2 : r --> G P3).
Hypothesis H : Pullback_eq1 (FMor G F12) (FMor G F32) t1 t2.
(* construction de r# *)
Definition Pulb_tau (a : PULB) :=
match a as a' return (Carrier (r --> G a')) with
| P1 => t1
| P2 => t1 o FMor G F12
| P3 => t2
end.

(* Specifications: *)
Lemma Pulb_cone_law : Cone_law Pulb_tau.
Definition Pulb_cone : Cone r G := Pulb_cone_law.