--- /dev/null
+
+include "logic/equality.ma".
+(* Inclusion of: LAT039-1.p *)
+(* -------------------------------------------------------------------------- *)
+(* File : LAT039-1 : TPTP v3.1.1. Released v2.4.0. *)
+(* Domain : Lattice Theory *)
+(* Problem : Every distributive lattice is modular *)
+(* Version : [McC88] (equality) axioms. *)
+(* Theorem formulation : Modularity is expressed by: *)
+(* x <= y -> x v (y & z) = y & (x v z) *)
+(* English : *)
+(* Refs : [DeN00] DeNivelle (2000), Email to G. Sutcliffe *)
+(* [McC88] McCune (1988), Challenge Equality Problems in Lattice *)
+(* Source : [DeN00] *)
+(* Names : lattice-mod-2 [DeN00] *)
+(* Status : Unsatisfiable *)
+(* Rating : 0.00 v2.4.0 *)
+(* Syntax : Number of clauses : 12 ( 0 non-Horn; 12 unit; 2 RR) *)
+(* Number of atoms : 12 ( 12 equality) *)
+(* Maximal clause size : 1 ( 1 average) *)
+(* Number of predicates : 1 ( 0 propositional; 2-2 arity) *)
+(* Number of functors : 5 ( 3 constant; 0-2 arity) *)
+(* Number of variables : 22 ( 2 singleton) *)
+(* Maximal term depth : 3 ( 2 average) *)
+(* Comments : *)
+(* -------------------------------------------------------------------------- *)
+(* ----Include lattice theory axioms *)
+(* Inclusion of: Axioms/LAT001-0.ax *)
+(* -------------------------------------------------------------------------- *)
+(* File : LAT001-0 : TPTP v3.1.1. Released v1.0.0. *)
+(* Domain : Lattice Theory *)
+(* Axioms : Lattice theory (equality) axioms *)
+(* Version : [McC88] (equality) axioms. *)
+(* English : *)
+(* Refs : [Bum65] Bumcroft (1965), Proceedings of the Glasgow Mathematic *)
+(* : [McC88] McCune (1988), Challenge Equality Problems in Lattice *)
+(* : [Wos88] Wos (1988), Automated Reasoning - 33 Basic Research Pr *)
+(* Source : [McC88] *)
+(* Names : *)
+(* Status : *)
+(* Syntax : Number of clauses : 8 ( 0 non-Horn; 8 unit; 0 RR) *)
+(* Number of literals : 8 ( 8 equality) *)
+(* Maximal clause size : 1 ( 1 average) *)
+(* Number of predicates : 1 ( 0 propositional; 2-2 arity) *)
+(* Number of functors : 2 ( 0 constant; 2-2 arity) *)
+(* Number of variables : 16 ( 2 singleton) *)
+(* Maximal term depth : 3 ( 2 average) *)
+(* Comments : *)
+(* -------------------------------------------------------------------------- *)
+(* ----The following 8 clauses characterise lattices *)
+(* -------------------------------------------------------------------------- *)
+(* -------------------------------------------------------------------------- *)
+theorem rhs:
+ \forall Univ:Set.
+\forall join:\forall _:Univ.\forall _:Univ.Univ.
+\forall meet:\forall _:Univ.\forall _:Univ.Univ.
+\forall xx:Univ.
+\forall yy:Univ.
+\forall zz:Univ.
+\forall H0:eq Univ (join xx yy) yy.
+\forall H1:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (meet X (join Y Z)) (join (meet X Y) (meet X Z)).
+\forall H2:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (join X (meet Y Z)) (meet (join X Y) (join X Z)).
+\forall H3:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (join (join X Y) Z) (join X (join Y Z)).
+\forall H4:\forall X:Univ.\forall Y:Univ.\forall Z:Univ.eq Univ (meet (meet X Y) Z) (meet X (meet Y Z)).
+\forall H5:\forall X:Univ.\forall Y:Univ.eq Univ (join X Y) (join Y X).
+\forall H6:\forall X:Univ.\forall Y:Univ.eq Univ (meet X Y) (meet Y X).
+\forall H7:\forall X:Univ.\forall Y:Univ.eq Univ (join X (meet X Y)) X.
+\forall H8:\forall X:Univ.\forall Y:Univ.eq Univ (meet X (join X Y)) X.
+\forall H9:\forall X:Univ.eq Univ (join X X) X.
+\forall H10:\forall X:Univ.eq Univ (meet X X) X.eq Univ (join xx (meet yy zz)) (meet yy (join xx zz))
+.
+intros.
+autobatch paramodulation timeout=100;
+try assumption.
+print proofterm.
+qed.
+(* -------------------------------------------------------------------------- *)