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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.
(*-- Examples of intuitionistics tautologies Ref: Lincoln Wallen, Automated Deduction in Nonclassical Logics, 1990 Sthephen Klenne, Introduction to Metamathematics,1952. --*)

Theorem Ex_Wallen : (A -> B /\ C) -> (A -> B) \/ (A -> C).