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(* 02110-1301 USA                                                     *)


(* Contribution to the Coq Library   V6.3 (July 1999)                    *)

(*-- Tactics Tauto & Intuition --*)

(*-- Tauto: Tactic for automating proof in Intuionnistic Propositional 
            Caulculus, based on the contraction-free LJT of Dickhoff 
     Ref:   Roy Dyckhoff, The Journal of Symbolic Logic Volume 57,
            Number 3, Sept. 1992                                      --*) 

Parameter A B C : Prop.Parameter even : nat -> Prop.Parameter P : nat -> Prop.

Theorem a4 : ~ A -> ~ A.