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(* as published by the Free Software Foundation; either version 2.1   *)
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(*                                                                    *)
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(* GNU General Public License for more details.                       *)
(*                                                                    *)
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(* 02110-1301 USA                                                     *)
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(*          Projet Formel - Calculus of Inductive Constructions V5.10        *)
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(*									     *)
(*	         Category .->.<-. (used for Pullbacks)     		     *)
(*									     *)
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(*									     *)
(*                     A. SAIBI	  May 95                  		     *)
(*									     *)
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Require Export Category.
Require Export BasicTypes.
Set Implicit Arguments.
Unset Strict Implicit.
Inductive PULB_ob : Type :=
| P1 : PULB_ob
| P2 : PULB_ob
| P3 : PULB_ob.
Inductive PULB_mor : PULB_ob -> PULB_ob -> Type :=
| IP1 : PULB_mor P1 P1
| IP2 : PULB_mor P2 P2
| IP3 : PULB_mor P3 P3
| F12 : PULB_mor P1 P2
| F32 : PULB_mor P3 P2.
(* *)

Lemma PULB_21_P :
(PULB_mor P2 P1 -> Prop) -> forall a b : PULB_ob, PULB_mor a b -> Prop.