1 include "logic/equality.ma".
3 (* Inclusion of: LAT025-1.p *)
5 (* -------------------------------------------------------------------------- *)
7 (* File : LAT025-1 : TPTP v3.2.0. Released v2.2.0. *)
9 (* Domain : Lattice Theory (Ternary Near Lattices) *)
11 (* Problem : Non-uniqueness of meet (dually join) in TNL *)
13 (* Version : [MP96] (equality) axioms. *)
15 (* English : Let's say we have a ternary near-lattice (TNL) with two meet *)
17 (* operations, say meet1 and meet2. In other words, {join,meet1} *)
19 (* and {join,meet2} are TNLs. Are the two meets necessarily *)
21 (* the same? No, they aren't. Here is a counterexample. *)
23 (* Refs : [McC98] McCune (1998), Email to G. Sutcliffe *)
25 (* : [MP96] McCune & Padmanabhan (1996), Automated Deduction in Eq *)
27 (* Source : [McC98] *)
29 (* Names : TNL-2 [MP96] *)
31 (* Status : Satisfiable *)
33 (* Rating : 0.33 v3.2.0, 0.67 v3.1.0, 0.33 v2.4.0, 0.67 v2.3.0, 1.00 v2.2.1 *)
35 (* Syntax : Number of clauses : 15 ( 0 non-Horn; 15 unit; 1 RR) *)
37 (* Number of atoms : 15 ( 15 equality) *)
39 (* Maximal clause size : 1 ( 1 average) *)
41 (* Number of predicates : 1 ( 0 propositional; 2-2 arity) *)
43 (* Number of functors : 5 ( 2 constant; 0-2 arity) *)
45 (* Number of variables : 29 ( 12 singleton) *)
47 (* Maximal term depth : 4 ( 2 average) *)
49 (* Comments : The smallest model has 5 elements. *)
51 (* -------------------------------------------------------------------------- *)
53 (* ----{join,meet} is a TNL: *)
55 (* ----{join,meet2} is a TNL: *)
57 (* ----Denial of meet=meet2. *)
58 ntheorem prove_meets_equal:
59 ∀Univ:Type.∀X:Univ.∀Y:Univ.∀Z:Univ.
62 ∀join:∀_:Univ.∀_:Univ.Univ.
63 ∀meet:∀_:Univ.∀_:Univ.Univ.
64 ∀meet2:∀_:Univ.∀_:Univ.Univ.
65 ∀H0:∀X:Univ.∀Y:Univ.∀Z:Univ.eq Univ (meet2 X (join Y (join X Z))) X.
66 ∀H1:∀X:Univ.∀Y:Univ.∀Z:Univ.eq Univ (join X (meet2 Y (meet2 X Z))) X.
67 ∀H2:∀X:Univ.∀Y:Univ.eq Univ (meet2 X Y) (meet2 Y X).
68 ∀H3:∀X:Univ.∀Y:Univ.eq Univ (join X (meet2 X Y)) X.
69 ∀H4:∀X:Univ.∀Y:Univ.eq Univ (meet2 X (join X Y)) X.
70 ∀H5:∀X:Univ.eq Univ (meet2 X X) X.
71 ∀H6:∀X:Univ.∀Y:Univ.∀Z:Univ.eq Univ (meet X (join Y (join X Z))) X.
72 ∀H7:∀X:Univ.∀Y:Univ.∀Z:Univ.eq Univ (join X (meet Y (meet X Z))) X.
73 ∀H8:∀X:Univ.∀Y:Univ.eq Univ (join X Y) (join Y X).
74 ∀H9:∀X:Univ.∀Y:Univ.eq Univ (meet X Y) (meet Y X).
75 ∀H10:∀X:Univ.∀Y:Univ.eq Univ (join X (meet X Y)) X.
76 ∀H11:∀X:Univ.∀Y:Univ.eq Univ (meet X (join X Y)) X.
77 ∀H12:∀X:Univ.eq Univ (join X X) X.
78 ∀H13:∀X:Univ.eq Univ (meet X X) X.eq Univ (meet a b) (meet2 a b)
103 nauto by H0,H1,H2,H3,H4,H5,H6,H7,H8,H9,H10,H11,H12,H13;
106 (* -------------------------------------------------------------------------- *)