--- /dev/null
+include "logic/equality.ma".
+
+(* Inclusion of: LCL140-1.p *)
+
+(* -------------------------------------------------------------------------- *)
+
+(* File : LCL140-1 : TPTP v3.7.0. Released v1.0.0. *)
+
+(* Domain : Logic Calculi (Wajsberg Algebra) *)
+
+(* Problem : A lemma in Wajsberg algebras *)
+
+(* Version : [Bon91] (equality) axioms. *)
+
+(* English : *)
+
+(* Refs : [FRT84] Font et al. (1984), Wajsberg Algebras *)
+
+(* : [Bon91] Bonacina (1991), Problems in Lukasiewicz Logic *)
+
+(* Source : [Bon91] *)
+
+(* Names : Lemma 9 [Bon91] *)
+
+(* Status : Unsatisfiable *)
+
+(* Rating : 0.00 v2.2.1, 0.22 v2.2.0, 0.29 v2.1.0, 0.25 v2.0.0 *)
+
+(* Syntax : Number of clauses : 5 ( 0 non-Horn; 5 unit; 1 RR) *)
+
+(* Number of atoms : 5 ( 5 equality) *)
+
+(* Maximal clause size : 1 ( 1 average) *)
+
+(* Number of predicates : 1 ( 0 propositional; 2-2 arity) *)
+
+(* Number of functors : 4 ( 2 constant; 0-2 arity) *)
+
+(* Number of variables : 8 ( 0 singleton) *)
+
+(* Maximal term depth : 4 ( 2 average) *)
+
+(* Comments : *)
+
+(* -------------------------------------------------------------------------- *)
+
+(* ----Include Wajsberg algebra axioms *)
+
+(* Inclusion of: Axioms/LCL001-0.ax *)
+
+(* -------------------------------------------------------------------------- *)
+
+(* File : LCL001-0 : TPTP v3.7.0. Released v1.0.0. *)
+
+(* Domain : Logic Calculi (Wajsberg Algebras) *)
+
+(* Axioms : Wajsberg algebra axioms *)
+
+(* Version : [Bon91] (equality) axioms. *)
+
+(* English : *)
+
+(* Refs : [FRT84] Font et al. (1984), Wajsberg Algebras *)
+
+(* : [Bon91] Bonacina (1991), Problems in Lukasiewicz Logic *)
+
+(* : [MW92] McCune & Wos (1992), Experiments in Automated Deductio *)
+
+(* Source : [MW92] *)
+
+(* Names : MV Sentential Calculus [MW92] *)
+
+(* Status : *)
+
+(* Syntax : Number of clauses : 4 ( 0 non-Horn; 4 unit; 0 RR) *)
+
+(* Number of atoms : 4 ( 4 equality) *)
+
+(* Maximal clause size : 1 ( 1 average) *)
+
+(* Number of predicates : 1 ( 0 propositional; 2-2 arity) *)
+
+(* Number of functors : 3 ( 1 constant; 0-2 arity) *)
+
+(* Number of variables : 8 ( 0 singleton) *)
+
+(* Maximal term depth : 4 ( 2 average) *)
+
+(* Comments : *)
+
+(* -------------------------------------------------------------------------- *)
+
+(* -------------------------------------------------------------------------- *)
+
+(* -------------------------------------------------------------------------- *)
+ntheorem prove_wajsberg_lemma:
+ (∀Univ:Type.∀X:Univ.∀Y:Univ.∀Z:Univ.
+∀implies:∀_:Univ.∀_:Univ.Univ.
+∀not:∀_:Univ.Univ.
+∀truth:Univ.
+∀x:Univ.
+∀H0:∀X:Univ.∀Y:Univ.eq Univ (implies (implies (not X) (not Y)) (implies Y X)) truth.
+∀H1:∀X:Univ.∀Y:Univ.eq Univ (implies (implies X Y) Y) (implies (implies Y X) X).
+∀H2:∀X:Univ.∀Y:Univ.∀Z:Univ.eq Univ (implies (implies X Y) (implies (implies Y Z) (implies X Z))) truth.
+∀H3:∀X:Univ.eq Univ (implies truth X) X.eq Univ (not (not x)) x)
+.
+#Univ ##.
+#X ##.
+#Y ##.
+#Z ##.
+#implies ##.
+#not ##.
+#truth ##.
+#x ##.
+#H0 ##.
+#H1 ##.
+#H2 ##.
+#H3 ##.
+nauto by H0,H1,H2,H3 ##;
+ntry (nassumption) ##;
+nqed.
+
+(* -------------------------------------------------------------------------- *)