--- /dev/null
+
+include "logic/equality.ma".
+(* Inclusion of: LAT034-1.p *)
+(* -------------------------------------------------------------------------- *)
+(* File : LAT034-1 : TPTP v3.1.1. Bugfixed v2.5.0. *)
+(* Domain : Lattice Theory *)
+(* Problem : Idempotency of meet *)
+(* Version : [McC88] (equality) axioms. *)
+(* English : *)
+(* Refs : [DeN00] DeNivelle (2000), Email to G. Sutcliffe *)
+(* [McC88] McCune (1988), Challenge Equality Problems in Lattice *)
+(* Source : [DeN00] *)
+(* Names : idemp_of_meet [DeN00] *)
+(* Status : Unsatisfiable *)
+(* Rating : 0.00 v2.5.0 *)
+(* Syntax : Number of clauses : 7 ( 0 non-Horn; 7 unit; 1 RR) *)
+(* Number of atoms : 7 ( 7 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 : 14 ( 2 singleton) *)
+(* Maximal term depth : 3 ( 2 average) *)
+(* Comments : *)
+(* Bugfixes : v2.5.0 - Used axioms without the conjecture *)
+(* -------------------------------------------------------------------------- *)
+(* ----Include lattice theory axioms *)
+(* include('Axioms/LAT001-0.ax'). *)
+(* -------------------------------------------------------------------------- *)
+theorem idempotence_of_meet:
+ \forall Univ:Set.
+\forall join:\forall _:Univ.\forall _:Univ.Univ.
+\forall meet:\forall _:Univ.\forall _:Univ.Univ.
+\forall xx:Univ.
+\forall H0:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (join (join X Y) Z) (join X (join Y Z)).
+\forall H1:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (meet (meet X Y) Z) (meet X (meet Y Z)).
+\forall H2:\forall X:Univ.\forall Y:Univ.eq Univ (join X Y) (join Y X).
+\forall H3:\forall X:Univ.\forall Y:Univ.eq Univ (meet X Y) (meet Y X).
+\forall H4:\forall X:Univ.\forall Y:Univ.eq Univ (join X (meet X Y)) X.
+\forall H5:\forall X:Univ.\forall Y:Univ.eq Univ (meet X (join X Y)) X.eq Univ (meet xx xx) xx
+.
+intros.
+autobatch paramodulation timeout=100;
+try assumption.
+print proofterm.
+qed.
+(* -------------------------------------------------------------------------- *)