## TPTP Problem File: SET627+3.p

View Solutions - Solve Problem

```%--------------------------------------------------------------------------
% File     : SET627+3 : TPTP v8.1.0. Released v2.2.0.
% Domain   : Set Theory
% Problem  : X is disjoint from the empty set
% Version  : [Try90] axioms : Reduced > Incomplete.
% English  :

% Refs     : [ILF] The ILF Group (1998), The ILF System: A Tool for the Int
%          : [Try90] Trybulec (1990), Tarski Grothendieck Set Theory
%          : [TS89]  Trybulec & Swieczkowska (1989), Boolean Properties of
% Source   : [ILF]
% Names    : BOOLE (104) [TS89]

% Status   : Theorem
% Rating   : 0.00 v6.3.0, 0.08 v6.2.0, 0.00 v5.3.0, 0.09 v5.2.0, 0.00 v3.2.0, 0.11 v3.1.0, 0.00 v2.2.1
% Syntax   : Number of formulae    :    6 (   2 unt;   0 def)
%            Number of atoms       :   11 (   0 equ)
%            Maximal formula atoms :    3 (   1 avg)
%            Number of connectives :    8 (   3   ~;   0   |;   1   &)
%                                         (   3 <=>;   1  =>;   0  <=;   0 <~>)
%            Maximal formula depth :    6 (   4 avg)
%            Maximal term depth    :    1 (   1 avg)
%            Number of predicates  :    4 (   4 usr;   0 prp; 1-2 aty)
%            Number of functors    :    1 (   1 usr;   1 con; 0-0 aty)
%            Number of variables   :   11 (  10   !;   1   ?)
% SPC      : FOF_THM_RFO_NEQ

%--------------------------------------------------------------------------
%---- line(hidden - axiom190,1832636)
fof(empty_set_defn,axiom,
! [B] : ~ member(B,empty_set) ).

%---- line(boole - df(5),1833080)
fof(intersect_defn,axiom,
! [B,C] :
( intersect(B,C)
<=> ? [D] :
( member(D,B)
& member(D,C) ) ) ).

%---- line(boole - axiom191,1833083)
fof(disjoint_defn,axiom,
! [B,C] :
( disjoint(B,C)
<=> ~ intersect(B,C) ) ).

%---- property(symmetry,op(intersect,2,predicate))
fof(symmetry_of_intersect,axiom,
! [B,C] :
( intersect(B,C)
=> intersect(C,B) ) ).

%---- line(hidden - axiom193,1832628)
fof(empty_defn,axiom,
! [B] :
( empty(B)
<=> ! [C] : ~ member(C,B) ) ).

%---- line(boole - th(104),1834334)
fof(prove_th104,conjecture,
! [B] : disjoint(B,empty_set) ).

%--------------------------------------------------------------------------
```