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1 (**************************************************************************)
2 (*       ___                                                              *)
3 (*      ||M||                                                             *)
4 (*      ||A||       A project by Andrea Asperti                           *)
5 (*      ||T||                                                             *)
6 (*      ||I||       Developers:                                           *)
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10 (*       \ /        This file is distributed under the terms of the       *)
11 (*        v         GNU General Public License Version 2                  *)
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14
15 set "baseuri" "cic:/matita/LOGIC/PNF/defs".
16
17 (* NORMAL FORM PREDICATE FOR PROOFS IN CONTEXT
18    For cut elimination
19 *)
20
21 include "PEq/defs.ma".
22 include "PRed/defs.ma".
23
24 inductive PNF (P:Context) (p:Proof): Prop \def
25    | pnf: (\forall q,Q,S. [P, p, S] => [Q, q, S] \to [P, p] = [Q, q]) \to 
26           PNF P p
27 .