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generalize no more useful for elim
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1 (**************************************************************************)
2 (*       ___                                                              *)
3 (*      ||M||                                                             *)
4 (*      ||A||       A project by Andrea Asperti                           *)
5 (*      ||T||                                                             *)
6 (*      ||I||       Developers:                                           *)
7 (*      ||T||         The HELM team.                                      *)
8 (*      ||A||         http://helm.cs.unibo.it                             *)
9 (*      \   /                                                             *)
10 (*       \ /        This file is distributed under the terms of the       *)
11 (*        v         GNU General Public License Version 2                  *)
12 (*                                                                        *)
13 (**************************************************************************)
14
15 (* STATO: COMPILA *)
16
17 set "baseuri" "cic:/matita/logic/iff".
18
19 include "../../library/logic/connectives.ma".
20
21 definition Iff : Prop \to Prop \to Prop \def
22    \lambda A,B. (A \to B) \land (B \to A).
23    
24  (*CSC: the URI must disappear: there is a bug now *)
25 interpretation "logical iff" 'iff x y = (cic:/matita/logic/iff/Iff.con x y).
26
27 notation > "hvbox(a break \liff b)" 
28   left associative with precedence 25
29 for @{ 'iff $a $b }.
30
31 notation < "hvbox(a break \leftrightarrow b)" 
32   left associative with precedence 25
33 for @{ 'iff $a $b }.