## TPTP Problem File: SEU642^2.p

View Solutions - Solve Problem

```%------------------------------------------------------------------------------
% File     : SEU642^2 : TPTP v7.2.0. Released v3.7.0.
% Domain   : Set Theory
% Problem  : Ordered Pairs - Properties of Pairs
% Version  : Especial > Reduced > Especial.
%            (setadjoin y emptyset)) emptyset)) -> x = z)

% Refs     : [Bro08] Brown (2008), Email to G. Sutcliffe
% Source   : [Bro08]
% Names    : ZFC144l [Bro08]

% Status   : Theorem
% Rating   : 0.22 v7.2.0, 0.12 v7.1.0, 0.38 v7.0.0, 0.43 v6.4.0, 0.50 v6.3.0, 0.60 v6.2.0, 0.43 v6.1.0, 0.29 v6.0.0, 0.43 v5.5.0, 0.33 v5.4.0, 0.40 v5.2.0, 0.60 v5.1.0, 0.80 v5.0.0, 0.60 v4.1.0, 0.33 v4.0.1, 0.67 v4.0.0, 0.33 v3.7.0
% Syntax   : Number of formulae    :   12 (   0 unit;   7 type;   4 defn)
%            Number of atoms       :   66 (  10 equality;  24 variable)
%            Maximal formula depth :   16 (   6 average)
%            Number of connectives :   41 (   0   ~;   1   |;   0   &;  32   @)
%                                         (   0 <=>;   8  =>;   0  <=;   0 <~>)
%                                         (   0  ~|;   0  ~&)
%            Number of type conns  :    4 (   4   >;   0   *;   0   +;   0  <<)
%            Number of symbols     :    9 (   7   :;   0   =)
%            Number of variables   :   12 (   0 sgn;  12   !;   0   ?;   0   ^)
%                                         (  12   :;   0  !>;   0  ?*)
%                                         (   0  @-;   0  @+)
% SPC      : TH0_THM_EQU_NAR

%          :
%------------------------------------------------------------------------------
thf(in_type,type,(
in: \$i > \$i > \$o )).

thf(emptyset_type,type,(
emptyset: \$i )).

setadjoin: \$i > \$i > \$i )).

= ( ! [Xx: \$i,Xy: \$i] :
( in @ Xx @ ( setadjoin @ Xx @ Xy ) ) ) )).

thf(uniqinunit_type,type,(
uniqinunit: \$o )).

thf(uniqinunit,definition,
( uniqinunit
= ( ! [Xx: \$i,Xy: \$i] :
( ( in @ Xx @ ( setadjoin @ Xy @ emptyset ) )
=> ( Xx = Xy ) ) ) )).

thf(upairset2E_type,type,(
upairset2E: \$o )).

thf(upairset2E,definition,
( upairset2E
= ( ! [Xx: \$i,Xy: \$i,Xz: \$i] :
( ( in @ Xz @ ( setadjoin @ Xx @ ( setadjoin @ Xy @ emptyset ) ) )
=> ( ( Xz = Xx )
| ( Xz = Xy ) ) ) ) )).

thf(singletonsuniq_type,type,(
singletonsuniq: \$o )).

thf(singletonsuniq,definition,
( singletonsuniq
= ( ! [Xx: \$i,Xy: \$i] :
( ( ( setadjoin @ Xx @ emptyset )
= ( setadjoin @ Xy @ emptyset ) )
=> ( Xx = Xy ) ) ) )).

thf(setukpairinjL1,conjecture,