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DT2H2X---1.9.5.THM-Ref.s

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%------------------------------------------------------------------------------
% File     : DT2H2X---1.9.5
% Problem  : SEU706^2 : TPTP v9.2.1. Released v3.7.0.
% Transfm  : none
% Format   : tptp:raw
% Command  : /export/starexec/sandbox2/solver/bin/run_DT2H2X /export/starexec/sandbox2/benchmark/theBenchmark.p 300

% Computer : n031.cluster.edu
% Model    : x86_64 x86_64
% CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 2.10GHz
% Memory   : 8042.1875MB
% OS       : Linux 3.10.0-693.el7.x86_64
% CPULimit : 300s
% WCLimit  : 300s
% DateTime : Wed Feb 25 09:36:33 AM UTC 2026

% Result   : Theorem 1.51s 1.29s
% Output   : Refutation 1.51s
% Verified : 
% SZS Type : Refutation
%            Derivation depth      :   17
%            Number of leaves      :    8
% Syntax   : Number of formulae    :   50 (  23 unt;   0 typ;   0 def)
%            Number of atoms       :  424 ( 139 equ;   0 cnn)
%            Maximal formula atoms :    8 (   8 avg)
%            Number of connectives :  348 (  41   ~;  25   |;  46   &; 194   @)
%                                         (   3 <=>;  35  =>;   0  <=;   0 <~>)
%            Maximal formula depth :   13 (   4 avg)
%            Number of types       :    2 (   0 usr)
%            Number of type conns  :    0 (   0   >;   0   *;   0   +;   0  <<)
%            Number of symbols     :   20 (  16 usr;  15 con; 0-2 aty)
%                                         (   0  !!;   4  ??;   0 @@+;   0 @@-)
%            Number of variables   :   66 (  10   ^;  37   !;  19   ?;  66   :)

% Comments : 
%------------------------------------------------------------------------------
thf(func_def_0,type,
    in: $i > $i > $o ).

thf(func_def_2,type,
    setadjoin: $i > $i > $i ).

thf(func_def_3,type,
    setunion: $i > $i ).

thf(func_def_10,type,
    singleton: $i > $o ).

thf(f115,plain,
    $false,
    inference(subsumption_resolution,[status(thm)],[f114,f110]) ).

thf(f110,plain,
    sK16 != sK10,
    inference(superposition,[status(thm)],[f72,f109]) ).

thf(f109,plain,
    ( sK16
    = ( setunion @ sK9 ) ),
    inference(superposition,[status(thm)],[f107,f106]) ).

thf(f106,plain,
    ( sK9
    = ( setadjoin @ sK16 @ emptyset ) ),
    inference(equality_proxy_clausification,[status(thm)],[f104]) ).

thf(f104,plain,
    ( $true
    = ( ( setadjoin @ sK16 @ emptyset )
      = sK9 ) ),
    inference(binary_proxy_clausification,[status(thm)],[f103]) ).

thf(f103,plain,
    ( $true
    = ( ( in @ sK16 @ sK9 )
      & ( ( setadjoin @ sK16 @ emptyset )
        = sK9 ) ) ),
    inference(beta_eta_normalization,[status(thm)],[f102]) ).

thf(f102,plain,
    ( $true
    = ( ^ [Y0: $i] :
          ( ( in @ Y0 @ sK9 )
          & ( ( setadjoin @ Y0 @ emptyset )
            = sK9 ) )
      @ sK16 ) ),
    inference(sigma_clausification,[status(thm)],[f101]) ).

thf(f101,plain,
    ( $true
    = ( ?? @ $i
      @ ^ [Y0: $i] :
          ( ( in @ Y0 @ sK9 )
          & ( ( setadjoin @ Y0 @ emptyset )
            = sK9 ) ) ) ),
    inference(beta_eta_normalization,[status(thm)],[f91]) ).

thf(f91,plain,
    ( $true
    = ( ^ [Y0: $i] :
          ( ?? @ $i
          @ ^ [Y1: $i] :
              ( ( in @ Y1 @ Y0 )
              & ( ( setadjoin @ Y1 @ emptyset )
                = Y0 ) ) )
      @ sK9 ) ),
    inference(definition_unfolding,[status(thm)],[f70,f61]) ).

thf(f61,plain,
    ( singleton
    = ( ^ [Y0: $i] :
          ( ?? @ $i
          @ ^ [Y1: $i] :
              ( ( in @ Y1 @ Y0 )
              & ( ( setadjoin @ Y1 @ emptyset )
                = Y0 ) ) ) ) ),
    inference(cnf_transformation,[status(thm)],[f15]) ).

thf(f15,plain,
    ( singleton
    = ( ^ [Y0: $i] :
          ( ?? @ $i
          @ ^ [Y1: $i] :
              ( ( in @ Y1 @ Y0 )
              & ( ( setadjoin @ Y1 @ emptyset )
                = Y0 ) ) ) ) ),
    inference(fool_elimination,[status(thm)],[f14]) ).

thf(f14,plain,
    ( singleton
    = ( ^ [X0: $i] :
        ? [X1: $i] :
          ( ( ( setadjoin @ X1 @ emptyset )
            = X0 )
          & ( in @ X1 @ X0 ) ) ) ),
    inference(rectify,[status(thm)],[f6]) ).

thf(f6,axiom,
    ( singleton
    = ( ^ [X2: $i] :
        ? [X0: $i] :
          ( ( ( setadjoin @ X0 @ emptyset )
            = X2 )
          & ( in @ X0 @ X2 ) ) ) ),
    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',singleton) ).

thf(f70,plain,
    ( $true
    = ( singleton @ sK9 ) ),
    inference(cnf_transformation,[status(thm)],[f48]) ).

thf(f48,plain,
    ( ( uniqinunit = $true )
    & ( setunionsingleton = $true )
    & ( sK10
     != ( setunion @ sK9 ) )
    & ( $true
      = ( in @ sK10 @ sK9 ) )
    & ( $true
      = ( singleton @ sK9 ) )
    & ( setadjoin__Cong = $true )
    & ( in__Cong = $true )
    & ( setunion__Cong = $true ) ),
    inference(skolemisation,[status(esa),new_symbols(skolem,[sK9,sK10])],[f24,f47,f46]) ).

thf(f46,plain,
    ( ? [X0: $i] :
        ( ? [X1: $i] :
            ( ( ( setunion @ X0 )
             != X1 )
            & ( $true
              = ( in @ X1 @ X0 ) ) )
        & ( $true
          = ( singleton @ X0 ) ) )
   => ( ? [X1: $i] :
          ( ( ( setunion @ sK9 )
           != X1 )
          & ( $true
            = ( in @ X1 @ sK9 ) ) )
      & ( $true
        = ( singleton @ sK9 ) ) ) ),
    introduced(definition,[],[choice_axiom]) ).

thf(f47,plain,
    ( ? [X1: $i] :
        ( ( ( setunion @ sK9 )
         != X1 )
        & ( $true
          = ( in @ X1 @ sK9 ) ) )
   => ( ( sK10
       != ( setunion @ sK9 ) )
      & ( $true
        = ( in @ sK10 @ sK9 ) ) ) ),
    introduced(definition,[],[choice_axiom]) ).

thf(f24,plain,
    ( ( uniqinunit = $true )
    & ( setunionsingleton = $true )
    & ? [X0: $i] :
        ( ? [X1: $i] :
            ( ( ( setunion @ X0 )
             != X1 )
            & ( $true
              = ( in @ X1 @ X0 ) ) )
        & ( $true
          = ( singleton @ X0 ) ) )
    & ( setadjoin__Cong = $true )
    & ( in__Cong = $true )
    & ( setunion__Cong = $true ) ),
    inference(flattening,[status(thm)],[f23]) ).

thf(f23,plain,
    ( ? [X0: $i] :
        ( ? [X1: $i] :
            ( ( ( setunion @ X0 )
             != X1 )
            & ( $true
              = ( in @ X1 @ X0 ) ) )
        & ( $true
          = ( singleton @ X0 ) ) )
    & ( setunionsingleton = $true )
    & ( setunion__Cong = $true )
    & ( setadjoin__Cong = $true )
    & ( in__Cong = $true )
    & ( uniqinunit = $true ) ),
    inference(ennf_transformation,[status(thm)],[f18]) ).

thf(f18,plain,
    ~ ( ( uniqinunit = $true )
     => ( ( in__Cong = $true )
       => ( ( setadjoin__Cong = $true )
         => ( ( setunion__Cong = $true )
           => ( ( setunionsingleton = $true )
             => ! [X0: $i] :
                  ( ( $true
                    = ( singleton @ X0 ) )
                 => ! [X1: $i] :
                      ( ( $true
                        = ( in @ X1 @ X0 ) )
                     => ( ( setunion @ X0 )
                        = X1 ) ) ) ) ) ) ) ),
    inference(fool_elimination,[status(thm)],[f17]) ).

thf(f17,plain,
    ~ ( uniqinunit
     => ( in__Cong
       => ( setadjoin__Cong
         => ( setunion__Cong
           => ( setunionsingleton
             => ! [X0: $i] :
                  ( ( singleton @ X0 )
                 => ! [X1: $i] :
                      ( ( in @ X1 @ X0 )
                     => ( ( setunion @ X0 )
                        = X1 ) ) ) ) ) ) ) ),
    inference(rectify,[status(thm)],[f8]) ).

thf(f8,negated_conjecture,
    ~ ( uniqinunit
     => ( in__Cong
       => ( setadjoin__Cong
         => ( setunion__Cong
           => ( setunionsingleton
             => ! [X6: $i] :
                  ( ( singleton @ X6 )
                 => ! [X0: $i] :
                      ( ( in @ X0 @ X6 )
                     => ( ( setunion @ X6 )
                        = X0 ) ) ) ) ) ) ) ),
    inference(negated_conjecture,[status(cth)],[f7]) ).

thf(f7,conjecture,
    ( uniqinunit
   => ( in__Cong
     => ( setadjoin__Cong
       => ( setunion__Cong
         => ( setunionsingleton
           => ! [X6: $i] :
                ( ( singleton @ X6 )
               => ! [X0: $i] :
                    ( ( in @ X0 @ X6 )
                   => ( ( setunion @ X6 )
                      = X0 ) ) ) ) ) ) ) ),
    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',theeq) ).

thf(f107,plain,
    ! [X0: $i] :
      ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
      = X0 ),
    inference(trivial_inequality_removal,[status(thm)],[f89]) ).

thf(f89,plain,
    ! [X0: $i] :
      ( ( $true != $true )
      | ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
        = X0 ) ),
    inference(definition_unfolding,[status(thm)],[f66,f73]) ).

thf(f73,plain,
    setunionsingleton = $true,
    inference(cnf_transformation,[status(thm)],[f48]) ).

thf(f66,plain,
    ! [X0: $i] :
      ( ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
        = X0 )
      | ( setunionsingleton != $true ) ),
    inference(cnf_transformation,[status(thm)],[f45]) ).

thf(f45,plain,
    ( ( ! [X0: $i] :
          ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
          = X0 )
      | ( setunionsingleton != $true ) )
    & ( ( setunionsingleton = $true )
      | ( sK8
       != ( setunion @ ( setadjoin @ sK8 @ emptyset ) ) ) ) ),
    inference(skolemisation,[status(esa),new_symbols(skolem,[sK8])],[f43,f44]) ).

thf(f44,plain,
    ( ? [X1: $i] :
        ( ( setunion @ ( setadjoin @ X1 @ emptyset ) )
       != X1 )
   => ( sK8
     != ( setunion @ ( setadjoin @ sK8 @ emptyset ) ) ) ),
    introduced(definition,[],[choice_axiom]) ).

thf(f43,plain,
    ( ( ! [X0: $i] :
          ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
          = X0 )
      | ( setunionsingleton != $true ) )
    & ( ( setunionsingleton = $true )
      | ? [X1: $i] :
          ( ( setunion @ ( setadjoin @ X1 @ emptyset ) )
         != X1 ) ) ),
    inference(rectify,[status(thm)],[f42]) ).

thf(f42,plain,
    ( ( ! [X0: $i] :
          ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
          = X0 )
      | ( setunionsingleton != $true ) )
    & ( ( setunionsingleton = $true )
      | ? [X0: $i] :
          ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
         != X0 ) ) ),
    inference(nnf_transformation,[status(thm)],[f16]) ).

thf(f16,plain,
    ( ! [X0: $i] :
        ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
        = X0 )
  <=> ( setunionsingleton = $true ) ),
    inference(fool_elimination,[status(thm)],[f5]) ).

thf(f5,axiom,
    ! [X0: $i] :
      ( ( ( setunion @ ( setadjoin @ X0 @ emptyset ) )
        = X0 )
      = setunionsingleton ),
    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',setunionsingleton) ).

thf(f72,plain,
    ( sK10
   != ( setunion @ sK9 ) ),
    inference(cnf_transformation,[status(thm)],[f48]) ).

thf(f114,plain,
    sK16 = sK10,
    inference(trivial_inequality_removal,[status(thm)],[f112]) ).

thf(f112,plain,
    ( ( $true != $true )
    | ( sK16 = sK10 ) ),
    inference(superposition,[status(thm)],[f111,f71]) ).

thf(f71,plain,
    ( $true
    = ( in @ sK10 @ sK9 ) ),
    inference(cnf_transformation,[status(thm)],[f48]) ).

thf(f111,plain,
    ! [X0: $i] :
      ( ( $true
       != ( in @ X0 @ sK9 ) )
      | ( sK16 = X0 ) ),
    inference(superposition,[status(thm)],[f108,f106]) ).

thf(f108,plain,
    ! [X0: $i,X1: $i] :
      ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
       != $true )
      | ( X0 = X1 ) ),
    inference(trivial_inequality_removal,[status(thm)],[f86]) ).

thf(f86,plain,
    ! [X0: $i,X1: $i] :
      ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
       != $true )
      | ( X0 = X1 )
      | ( $true != $true ) ),
    inference(definition_unfolding,[status(thm)],[f64,f74]) ).

thf(f74,plain,
    uniqinunit = $true,
    inference(cnf_transformation,[status(thm)],[f48]) ).

thf(f64,plain,
    ! [X0: $i,X1: $i] :
      ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
       != $true )
      | ( X0 = X1 )
      | ( uniqinunit != $true ) ),
    inference(cnf_transformation,[status(thm)],[f41]) ).

thf(f41,plain,
    ( ( ! [X0: $i,X1: $i] :
          ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
           != $true )
          | ( X0 = X1 ) )
      | ( uniqinunit != $true ) )
    & ( ( uniqinunit = $true )
      | ( ( $true
          = ( in @ sK6 @ ( setadjoin @ sK7 @ emptyset ) ) )
        & ( sK7 != sK6 ) ) ) ),
    inference(skolemisation,[status(esa),new_symbols(skolem,[sK6,sK7])],[f39,f40]) ).

thf(f40,plain,
    ( ? [X2: $i,X3: $i] :
        ( ( $true
          = ( in @ X2 @ ( setadjoin @ X3 @ emptyset ) ) )
        & ( X2 != X3 ) )
   => ( ( $true
        = ( in @ sK6 @ ( setadjoin @ sK7 @ emptyset ) ) )
      & ( sK7 != sK6 ) ) ),
    introduced(definition,[],[choice_axiom]) ).

thf(f39,plain,
    ( ( ! [X0: $i,X1: $i] :
          ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
           != $true )
          | ( X0 = X1 ) )
      | ( uniqinunit != $true ) )
    & ( ( uniqinunit = $true )
      | ? [X2: $i,X3: $i] :
          ( ( $true
            = ( in @ X2 @ ( setadjoin @ X3 @ emptyset ) ) )
          & ( X2 != X3 ) ) ) ),
    inference(rectify,[status(thm)],[f38]) ).

thf(f38,plain,
    ( ( ! [X0: $i,X1: $i] :
          ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
           != $true )
          | ( X0 = X1 ) )
      | ( uniqinunit != $true ) )
    & ( ( uniqinunit = $true )
      | ? [X0: $i,X1: $i] :
          ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
            = $true )
          & ( X0 != X1 ) ) ) ),
    inference(nnf_transformation,[status(thm)],[f26]) ).

thf(f26,plain,
    ( ! [X0: $i,X1: $i] :
        ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
         != $true )
        | ( X0 = X1 ) )
  <=> ( uniqinunit = $true ) ),
    inference(ennf_transformation,[status(thm)],[f20]) ).

thf(f20,plain,
    ( ( uniqinunit = $true )
  <=> ! [X0: $i,X1: $i] :
        ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
          = $true )
       => ( X0 = X1 ) ) ),
    inference(fool_elimination,[status(thm)],[f19]) ).

thf(f19,plain,
    ! [X0: $i,X1: $i] :
      ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
       => ( X0 = X1 ) )
      = uniqinunit ),
    inference(rectify,[status(thm)],[f1]) ).

thf(f1,axiom,
    ! [X0: $i,X1: $i] :
      ( ( ( in @ X0 @ ( setadjoin @ X1 @ emptyset ) )
       => ( X0 = X1 ) )
      = uniqinunit ),
    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',uniqinunit) ).

%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.00/0.12  % Problem  : SEU706^2 : TPTP v9.2.1. Released v3.7.0.
% 0.12/0.13  % Command  : /export/starexec/sandbox2/solver/bin/run_DT2H2X /export/starexec/sandbox2/benchmark/theBenchmark.p 300
% 0.17/0.34  % Computer : n031.cluster.edu
% 0.17/0.34  % Model    : x86_64 x86_64
% 0.17/0.34  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.17/0.34  % Memory   : 8042.1875MB
% 0.17/0.34  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.17/0.34  % CPULimit : 300
% 0.17/0.34  % WCLimit  : 300
% 0.17/0.34  % DateTime : Tue Feb 24 12:32:33 EST 2026
% 0.17/0.34  % CPUTime  : 
% 0.17/0.34  Running /export/starexec/sandbox2/solver/bin/run_DT2H2X /export/starexec/sandbox2/benchmark/theBenchmark.p 300
% 0.28/0.47  ---- Original DTF file ---
% 0.28/0.47  thf(spec,logic,$$dhol).
% 0.28/0.47  %------------------------------------------------------------------------------
% 0.28/0.47  % File     : SEU706^2 : TPTP v9.2.1. Released v3.7.0.
% 0.28/0.47  % Domain   : Set Theory
% 0.28/0.47  % Problem  : Conditionals
% 0.28/0.47  % Version  : Especial > Reduced > Especial.
% 0.28/0.47  % English  : (! X:i.singleton X -> (! x:i.in x X -> setunion X = x))
% 0.28/0.47  
% 0.28/0.47  % Refs     : [Bro08] Brown (2008), Email to G. Sutcliffe
% 0.28/0.47  % Source   : [Bro08]
% 0.28/0.47  % Names    : ZFC208l [Bro08]
% 0.28/0.47  
% 0.28/0.47  % Status   : Theorem
% 0.28/0.47  % Rating   : 0.00 v8.2.0, 0.08 v8.1.0, 0.00 v7.4.0, 0.11 v7.2.0, 0.00 v7.1.0, 0.25 v7.0.0, 0.14 v6.4.0, 0.17 v6.3.0, 0.20 v6.2.0, 0.14 v6.1.0, 0.29 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
% 0.28/0.47  % Syntax   : Number of formulae    :   17 (   6 unt;  10 typ;   6 def)
% 0.28/0.47  %            Number of atoms       :   34 (  17 equ;   0 cnn)
% 0.28/0.47  %            Maximal formula atoms :    8 (   4 avg)
% 0.28/0.47  %            Number of connectives :   40 (   0   ~;   0   |;   1   &;  25   @)
% 0.28/0.47  %                                         (   1 <=>;  13  =>;   0  <=;   0 <~>)
% 0.28/0.47  %            Maximal formula depth :   12 (   3 avg)
% 0.28/0.47  %            Number of types       :    2 (   0 usr)
% 0.28/0.47  %            Number of type conns  :    6 (   6   >;   0   *;   0   +;   0  <<)
% 0.28/0.47  %            Number of symbols     :   11 (  10 usr;   6 con; 0-2 aty)
% 0.28/0.47  %            Number of variables   :   17 (   1   ^;  15   !;   1   ?;  17   :)
% 0.28/0.47  % SPC      : TH0_THM_EQU_NAR
% 0.28/0.47  
% 0.28/0.47  % Comments : http://mathgate.info/detsetitem.php?id=262
% 0.28/0.47  %------------------------------------------------------------------------------
% 0.28/0.47  thf(in_type,type,
% 0.28/0.47      in: $i > $i > $o ).
% 0.28/0.47  
% 0.28/0.47  thf(emptyset_type,type,
% 0.28/0.47      emptyset: $i ).
% 0.28/0.47  
% 0.28/0.47  thf(setadjoin_type,type,
% 0.28/0.47      setadjoin: $i > $i > $i ).
% 0.28/0.47  
% 0.28/0.47  thf(setunion_type,type,
% 0.28/0.47      setunion: $i > $i ).
% 0.28/0.47  
% 0.28/0.47  thf(uniqinunit_type,type,
% 0.28/0.47      uniqinunit: $o ).
% 0.28/0.47  
% 0.28/0.47  thf(uniqinunit,definition,
% 0.28/0.47      ( uniqinunit
% 0.28/0.47      = ( ! [Xx: $i,Xy: $i] :
% 0.28/0.47            ( ( in @ Xx @ ( setadjoin @ Xy @ emptyset ) )
% 0.28/0.47           => ( Xx = Xy ) ) ) ) ).
% 0.28/0.47  
% 0.28/0.47  thf(in__Cong_type,type,
% 0.28/0.47      in__Cong: $o ).
% 0.28/0.47  
% 0.28/0.47  thf(in__Cong,definition,
% 0.28/0.47      ( in__Cong
% 0.28/0.47      = ( ! [A: $i,B: $i] :
% 0.28/0.47            ( ( A = B )
% 0.28/0.47           => ! [Xx: $i,Xy: $i] :
% 0.28/0.47                ( ( Xx = Xy )
% 0.28/0.47               => ( ( in @ Xx @ A )
% 0.28/0.47                <=> ( in @ Xy @ B ) ) ) ) ) ) ).
% 0.28/0.47  
% 0.28/0.47  thf(setadjoin__Cong_type,type,
% 0.28/0.47      setadjoin__Cong: $o ).
% 0.28/0.47  
% 0.28/0.47  thf(setadjoin__Cong,definition,
% 0.28/0.47      ( setadjoin__Cong
% 0.28/0.47      = ( ! [Xx: $i,Xy: $i] :
% 0.28/0.47            ( ( Xx = Xy )
% 0.28/0.47           => ! [Xz: $i,Xu: $i] :
% 0.28/0.47                ( ( Xz = Xu )
% 0.28/0.47               => ( ( setadjoin @ Xx @ Xz )
% 0.28/0.47                  = ( setadjoin @ Xy @ Xu ) ) ) ) ) ) ).
% 0.28/0.47  
% 0.28/0.47  thf(setunion__Cong_type,type,
% 0.28/0.47      setunion__Cong: $o ).
% 0.28/0.47  
% 0.28/0.47  thf(setunion__Cong,definition,
% 0.28/0.47      ( setunion__Cong
% 0.28/0.47      = ( ! [A: $i,B: $i] :
% 0.28/0.47            ( ( A = B )
% 0.28/0.47           => ( ( setunion @ A )
% 0.28/0.47              = ( setunion @ B ) ) ) ) ) ).
% 0.28/0.47  
% 0.28/0.47  thf(setunionsingleton_type,type,
% 0.28/0.47      setunionsingleton: $o ).
% 0.28/0.47  
% 0.28/0.47  thf(setunionsingleton,definition,
% 0.28/0.47      ( setunionsingleton
% 0.28/0.47      = ( ! [Xx: $i] :
% 0.28/0.47            ( ( setunion @ ( setadjoin @ Xx @ emptyset ) )
% 0.28/0.47            = Xx ) ) ) ).
% 0.28/0.47  
% 0.28/0.47  thf(singleton_type,type,
% 0.28/0.47      singleton: $i > $o ).
% 0.28/0.47  
% 0.28/0.47  thf(singleton,definition,
% 0.28/0.47      ( singleton
% 0.28/0.47      = ( ^ [A: $i] :
% 0.28/0.47          ? [Xx: $i] :
% 0.28/0.47            ( ( in @ Xx @ A )
% 0.28/0.47            & ( A
% 0.28/0.47              = ( setadjoin @ Xx @ emptyset ) ) ) ) ) ).
% 0.28/0.47  
% 0.28/0.47  thf(theeq,conjecture,
% 0.28/0.47      ( uniqinunit
% 0.28/0.47     => ( in__Cong
% 0.28/0.47       => ( setadjoin__Cong
% 0.28/0.47         => ( setunion__Cong
% 0.28/0.47           => ( setunionsingleton
% 0.28/0.47             => ! [X: $i] :
% 0.28/0.47                  ( ( singleton @ X )
% 0.28/0.47                 => ! [Xx: $i] :
% 0.28/0.47                      ( ( in @ Xx @ X )
% 0.28/0.47                     => ( ( setunion @ X )
% 0.28/0.47                        = Xx ) ) ) ) ) ) ) ) ).
% 0.28/0.47  
% 0.28/0.47  %------------------------------------------------------------------------------
% 0.28/0.47  ------------------------
% 1.51/1.25  ---- Embedded in THF ---
% 1.51/1.25  %%% This output was generated by embedproblem, version 1.9.5 (library version 1.9).
% 1.51/1.25  %%% Generated on Tue Feb 24 12:32:34 EST 2026
% 1.51/1.25  %%% using '$$dhol' embedding, version 1.3.0.
% 1.51/1.25  %%% Logic specification used:
% 1.51/1.25  %%% thf(spec, logic, $$dhol).
% 1.51/1.25  
% 1.51/1.25  % SZS output start ListOfTHF for /export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2DTF26023.p
% See solution above
% 1.51/1.25  ------------------------
% 1.51/1.26  ---- Cleaned THF ---
% 1.51/1.27  thf(in_type,type,
% 1.51/1.27      in: $i > $i > $o ).
% 1.51/1.27  
% 1.51/1.27  thf(emptyset_type,type,
% 1.51/1.27      emptyset: $i ).
% 1.51/1.27  
% 1.51/1.27  thf(setadjoin_type,type,
% 1.51/1.27      setadjoin: $i > $i > $i ).
% 1.51/1.27  
% 1.51/1.27  thf(setunion_type,type,
% 1.51/1.27      setunion: $i > $i ).
% 1.51/1.27  
% 1.51/1.27  thf(uniqinunit_type,type,
% 1.51/1.27      uniqinunit: $o ).
% 1.51/1.27  
% 1.51/1.27  thf(uniqinunit,definition,
% 1.51/1.27      ( uniqinunit
% 1.51/1.27      = ( ! [Xx: $i,Xy: $i] :
% 1.51/1.27            ( ( in @ Xx @ ( setadjoin @ Xy @ emptyset ) )
% 1.51/1.27           => ( Xx = Xy ) ) ) ) ).
% 1.51/1.27  
% 1.51/1.27  thf(in__Cong_type,type,
% 1.51/1.27      in__Cong: $o ).
% 1.51/1.27  
% 1.51/1.27  thf(in__Cong,definition,
% 1.51/1.27      ( in__Cong
% 1.51/1.27      = ( ! [A: $i,B: $i] :
% 1.51/1.27            ( ( A = B )
% 1.51/1.27           => ! [Xx: $i,Xy: $i] :
% 1.51/1.27                ( ( Xx = Xy )
% 1.51/1.27               => ( ( in @ Xx @ A )
% 1.51/1.27                <=> ( in @ Xy @ B ) ) ) ) ) ) ).
% 1.51/1.27  
% 1.51/1.27  thf(setadjoin__Cong_type,type,
% 1.51/1.27      setadjoin__Cong: $o ).
% 1.51/1.27  
% 1.51/1.27  thf(setadjoin__Cong,definition,
% 1.51/1.27      ( setadjoin__Cong
% 1.51/1.27      = ( ! [Xx: $i,Xy: $i] :
% 1.51/1.27            ( ( Xx = Xy )
% 1.51/1.27           => ! [Xz: $i,Xu: $i] :
% 1.51/1.27                ( ( Xz = Xu )
% 1.51/1.27               => ( ( setadjoin @ Xx @ Xz )
% 1.51/1.27                  = ( setadjoin @ Xy @ Xu ) ) ) ) ) ) ).
% 1.51/1.27  
% 1.51/1.27  thf(setunion__Cong_type,type,
% 1.51/1.27      setunion__Cong: $o ).
% 1.51/1.27  
% 1.51/1.27  thf(setunion__Cong,definition,
% 1.51/1.27      ( setunion__Cong
% 1.51/1.27      = ( ! [A: $i,B: $i] :
% 1.51/1.27            ( ( A = B )
% 1.51/1.27           => ( ( setunion @ A )
% 1.51/1.27              = ( setunion @ B ) ) ) ) ) ).
% 1.51/1.27  
% 1.51/1.27  thf(setunionsingleton_type,type,
% 1.51/1.27      setunionsingleton: $o ).
% 1.51/1.27  
% 1.51/1.27  thf(setunionsingleton,definition,
% 1.51/1.27      ( setunionsingleton
% 1.51/1.27      = ( ! [Xx: $i] :
% 1.51/1.27            ( ( setunion @ ( setadjoin @ Xx @ emptyset ) )
% 1.51/1.27            = Xx ) ) ) ).
% 1.51/1.27  
% 1.51/1.27  thf(singleton_type,type,
% 1.51/1.27      singleton: $i > $o ).
% 1.51/1.27  
% 1.51/1.27  thf(singleton,definition,
% 1.51/1.27      ( singleton
% 1.51/1.27      = ( ^ [A: $i] :
% 1.51/1.27          ? [Xx: $i] :
% 1.51/1.27            ( ( in @ Xx @ A )
% 1.51/1.27            & ( A
% 1.51/1.27              = ( setadjoin @ Xx @ emptyset ) ) ) ) ) ).
% 1.51/1.27  
% 1.51/1.27  thf(theeq,conjecture,
% 1.51/1.27      ( uniqinunit
% 1.51/1.27     => ( in__Cong
% 1.51/1.27       => ( setadjoin__Cong
% 1.51/1.27         => ( setunion__Cong
% 1.51/1.27           => ( setunionsingleton
% 1.51/1.27             => ! [X: $i] :
% 1.51/1.27                  ( ( singleton @ X )
% 1.51/1.27                 => ! [Xx: $i] :
% 1.51/1.27                      ( ( in @ Xx @ X )
% 1.51/1.27                     => ( ( setunion @ X )
% 1.51/1.27                        = Xx ) ) ) ) ) ) ) ) ).
% 1.51/1.27  ------------------------
% 1.51/1.28  % (26292)lrs+1002_1:1_au=on:bd=off:e2e=on:sd=2:sos=on:ss=axioms:i=275:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/275Mi)
% 1.51/1.28  % (26290)lrs+10_1:1_au=on:inj=on:i=2:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/2Mi)
% 1.51/1.28  % (26290)Instruction limit reached!
% 1.51/1.28  % (26290)------------------------------
% 1.51/1.28  % (26290)Version: Vampire 4.8 (commit 7b44b1c2f on 2025-07-15 09:50:17 +0100)
% 1.51/1.28  % (26290)Termination reason: Unknown
% 1.51/1.28  % (26290)Termination phase: Preprocessing 3
% 1.51/1.28  
% 1.51/1.28  % (26290)Memory used [KB]: 1023
% 1.51/1.28  % (26290)Time elapsed: 0.002 s
% 1.51/1.28  % (26290)Instructions burned: 2 (million)
% 1.51/1.28  % (26290)------------------------------
% 1.51/1.28  % (26290)------------------------------
% 1.51/1.28  % (26292)Refutation not found, incomplete strategy
% 1.51/1.28  % (26292)------------------------------
% 1.51/1.28  % (26292)Version: Vampire 4.8 (commit 7b44b1c2f on 2025-07-15 09:50:17 +0100)
% 1.51/1.28  % (26292)Termination reason: Refutation not found, incomplete strategy
% 1.51/1.28  
% 1.51/1.28  
% 1.51/1.28  % (26292)Memory used [KB]: 5500
% 1.51/1.28  % (26292)Time elapsed: 0.003 s
% 1.51/1.28  % (26292)Instructions burned: 3 (million)
% 1.51/1.28  % (26292)------------------------------
% 1.51/1.28  % (26292)------------------------------
% 1.51/1.29  % (26288)lrs+10_1:1_c=on:cnfonf=conj_eager:fd=off:fe=off:kws=frequency:spb=intro:i=4:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/4Mi)
% 1.51/1.29  % (26287)lrs+1002_1:8_bd=off:fd=off:hud=10:tnu=1:i=183:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/183Mi)
% 1.51/1.29  % (26289)dis+1010_1:1_au=on:cbe=off:chr=on:fsr=off:hfsq=on:nm=64:sos=theory:sp=weighted_frequency:i=27:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/27Mi)
% 1.51/1.29  % (26291)lrs+1002_1:128_aac=none:au=on:cnfonf=lazy_not_gen_be_off:sos=all:i=2:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/2Mi)
% 1.51/1.29  % (26293)lrs+1004_1:128_cond=on:e2e=on:sp=weighted_frequency:i=18:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/18Mi)
% 1.51/1.29  % (26291)Instruction limit reached!
% 1.51/1.29  % (26291)------------------------------
% 1.51/1.29  % (26291)Version: Vampire 4.8 (commit 7b44b1c2f on 2025-07-15 09:50:17 +0100)
% 1.51/1.29  % (26291)Termination reason: Unknown
% 1.51/1.29  % (26291)Termination phase: shuffling
% 1.51/1.29  
% 1.51/1.29  % (26291)Memory used [KB]: 1023
% 1.51/1.29  % (26291)Time elapsed: 0.003 s
% 1.51/1.29  % (26291)Instructions burned: 2 (million)
% 1.51/1.29  % (26291)------------------------------
% 1.51/1.29  % (26291)------------------------------
% 1.51/1.29  % (26288)Instruction limit reached!
% 1.51/1.29  % (26288)------------------------------
% 1.51/1.29  % (26288)Version: Vampire 4.8 (commit 7b44b1c2f on 2025-07-15 09:50:17 +0100)
% 1.51/1.29  % (26288)Termination reason: Unknown
% 1.51/1.29  % (26288)Termination phase: Saturation
% 1.51/1.29  
% 1.51/1.29  % (26288)Memory used [KB]: 5500
% 1.51/1.29  % (26288)Time elapsed: 0.005 s
% 1.51/1.29  % (26288)Instructions burned: 5 (million)
% 1.51/1.29  % (26288)------------------------------
% 1.51/1.29  % (26288)------------------------------
% 1.51/1.29  % (26294)lrs+10_1:1_bet=on:cnfonf=off:fd=off:hud=5:inj=on:i=3:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/3Mi)
% 1.51/1.29  % (26293)First to succeed.
% 1.51/1.29  % (26295)lrs+1002_1:1_cnfonf=lazy_not_be_gen:hud=14:prag=on:sp=weighted_frequency:tnu=1:i=37:si=on:rtra=on_0 on DTF2THF_26023 for (2999ds/37Mi)
% 1.51/1.29  % (26294)Instruction limit reached!
% 1.51/1.29  % (26294)------------------------------
% 1.51/1.29  % (26294)Version: Vampire 4.8 (commit 7b44b1c2f on 2025-07-15 09:50:17 +0100)
% 1.51/1.29  % (26294)Termination reason: Unknown
% 1.51/1.29  % (26294)Termination phase: Saturation
% 1.51/1.29  
% 1.51/1.29  % (26294)Memory used [KB]: 5500
% 1.51/1.29  % (26294)Time elapsed: 0.003 s
% 1.51/1.29  % (26294)Instructions burned: 4 (million)
% 1.51/1.29  % (26294)------------------------------
% 1.51/1.29  % (26294)------------------------------
% 1.51/1.29  % (26293)Refutation found. Thanks to Tanya!
% 1.51/1.29  % SZS status Theorem for DTF2THF_26023
% 1.51/1.29  % SZS output start Proof for DTF2THF_26023
% 1.51/1.29  thf(func_def_0, type, in: $i > $i > $o).
% 1.51/1.29  thf(func_def_2, type, setadjoin: $i > $i > $i).
% 1.51/1.29  thf(func_def_3, type, setunion: $i > $i).
% 1.51/1.29  thf(func_def_10, type, singleton: $i > $o).
% 1.51/1.29  thf(f115,plain,(
% 1.51/1.29    $false),
% 1.51/1.29    inference(subsumption_resolution,[status(thm)],[f114,f110])).
% 1.51/1.29  thf(f110,plain,(
% 1.51/1.29    (sK16 != sK10)),
% 1.51/1.29    inference(superposition,[status(thm)],[f72,f109])).
% 1.51/1.29  thf(f109,plain,(
% 1.51/1.29    (sK16 = (setunion @ sK9))),
% 1.51/1.29    inference(superposition,[status(thm)],[f107,f106])).
% 1.51/1.29  thf(f106,plain,(
% 1.51/1.29    (sK9 = (setadjoin @ sK16 @ emptyset))),
% 1.51/1.29    inference(equality_proxy_clausification,[status(thm)],[f104])).
% 1.51/1.29  thf(f104,plain,(
% 1.51/1.29    ($true = ((setadjoin @ sK16 @ emptyset) = sK9))),
% 1.51/1.29    inference(binary_proxy_clausification,[status(thm)],[f103])).
% 1.51/1.29  thf(f103,plain,(
% 1.51/1.29    ($true = ((in @ sK16 @ sK9) & ((setadjoin @ sK16 @ emptyset) = sK9)))),
% 1.51/1.29    inference(beta_eta_normalization,[status(thm)],[f102])).
% 1.51/1.29  thf(f102,plain,(
% 1.51/1.29    ($true = ((^[Y0 : $i]: ((in @ Y0 @ sK9) & ((setadjoin @ Y0 @ emptyset) = sK9))) @ sK16))),
% 1.51/1.29    inference(sigma_clausification,[status(thm)],[f101])).
% 1.51/1.29  thf(f101,plain,(
% 1.51/1.29    ($true = (?? @ $i @ (^[Y0 : $i]: ((in @ Y0 @ sK9) & ((setadjoin @ Y0 @ emptyset) = sK9)))))),
% 1.51/1.29    inference(beta_eta_normalization,[status(thm)],[f91])).
% 1.51/1.29  thf(f91,plain,(
% 1.51/1.29    ($true = ((^[Y0 : $i]: (?? @ $i @ (^[Y1 : $i]: ((in @ Y1 @ Y0) & ((setadjoin @ Y1 @ emptyset) = Y0))))) @ sK9))),
% 1.51/1.29    inference(definition_unfolding,[status(thm)],[f70,f61])).
% 1.51/1.29  thf(f61,plain,(
% 1.51/1.29    (singleton = (^[Y0 : $i]: (?? @ $i @ (^[Y1 : $i]: ((in @ Y1 @ Y0) & ((setadjoin @ Y1 @ emptyset) = Y0))))))),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f15])).
% 1.51/1.29  thf(f15,plain,(
% 1.51/1.29    (singleton = (^[Y0 : $i]: (?? @ $i @ (^[Y1 : $i]: ((in @ Y1 @ Y0) & ((setadjoin @ Y1 @ emptyset) = Y0))))))),
% 1.51/1.29    inference(fool_elimination,[status(thm)],[f14])).
% 1.51/1.29  thf(f14,plain,(
% 1.51/1.29    (singleton = (^[X0 : $i] : (? [X1 : $i] : (((setadjoin @ X1 @ emptyset) = X0) & (in @ X1 @ X0)))))),
% 1.51/1.29    inference(rectify,[status(thm)],[f6])).
% 1.51/1.29  thf(f6,axiom,(
% 1.51/1.29    (singleton = (^[X2 : $i] : (? [X0 : $i] : (((setadjoin @ X0 @ emptyset) = X2) & (in @ X0 @ X2)))))),
% 1.51/1.29    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',singleton)).
% 1.51/1.29  thf(f70,plain,(
% 1.51/1.29    ($true = (singleton @ sK9))),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f48])).
% 1.51/1.29  thf(f48,plain,(
% 1.51/1.29    (uniqinunit = $true) & (setunionsingleton = $true) & (((sK10 != (setunion @ sK9)) & ($true = (in @ sK10 @ sK9))) & ($true = (singleton @ sK9))) & (setadjoin__Cong = $true) & (in__Cong = $true) & (setunion__Cong = $true)),
% 1.51/1.29    inference(skolemisation,[status(esa),new_symbols(skolem,[sK9,sK10])],[f24,f47,f46])).
% 1.51/1.29  thf(f46,plain,(
% 1.51/1.29    ? [X0 : $i] : (? [X1 : $i] : (((setunion @ X0) != X1) & ($true = (in @ X1 @ X0))) & ($true = (singleton @ X0))) => (? [X1 : $i] : (((setunion @ sK9) != X1) & ($true = (in @ X1 @ sK9))) & ($true = (singleton @ sK9)))),
% 1.51/1.29    introduced(definition,[],[choice_axiom])).
% 1.51/1.29  thf(f47,plain,(
% 1.51/1.29    ? [X1 : $i] : (((setunion @ sK9) != X1) & ($true = (in @ X1 @ sK9))) => ((sK10 != (setunion @ sK9)) & ($true = (in @ sK10 @ sK9)))),
% 1.51/1.29    introduced(definition,[],[choice_axiom])).
% 1.51/1.29  thf(f24,plain,(
% 1.51/1.29    (uniqinunit = $true) & (setunionsingleton = $true) & ? [X0 : $i] : (? [X1 : $i] : (((setunion @ X0) != X1) & ($true = (in @ X1 @ X0))) & ($true = (singleton @ X0))) & (setadjoin__Cong = $true) & (in__Cong = $true) & (setunion__Cong = $true)),
% 1.51/1.29    inference(flattening,[status(thm)],[f23])).
% 1.51/1.29  thf(f23,plain,(
% 1.51/1.29    ((((? [X0 : $i] : (? [X1 : $i] : (((setunion @ X0) != X1) & ($true = (in @ X1 @ X0))) & ($true = (singleton @ X0))) & (setunionsingleton = $true)) & (setunion__Cong = $true)) & (setadjoin__Cong = $true)) & (in__Cong = $true)) & (uniqinunit = $true)),
% 1.51/1.29    inference(ennf_transformation,[status(thm)],[f18])).
% 1.51/1.29  thf(f18,plain,(
% 1.51/1.29    ~((uniqinunit = $true) => ((in__Cong = $true) => ((setadjoin__Cong = $true) => ((setunion__Cong = $true) => ((setunionsingleton = $true) => ! [X0 : $i] : (($true = (singleton @ X0)) => ! [X1 : $i] : (($true = (in @ X1 @ X0)) => ((setunion @ X0) = X1))))))))),
% 1.51/1.29    inference(fool_elimination,[status(thm)],[f17])).
% 1.51/1.29  thf(f17,plain,(
% 1.51/1.29    ~(uniqinunit => (in__Cong => (setadjoin__Cong => (setunion__Cong => (setunionsingleton => ! [X0 : $i] : ((singleton @ X0) => ! [X1 : $i] : ((in @ X1 @ X0) => ((setunion @ X0) = X1))))))))),
% 1.51/1.29    inference(rectify,[status(thm)],[f8])).
% 1.51/1.29  thf(f8,negated_conjecture,(
% 1.51/1.29    ~(uniqinunit => (in__Cong => (setadjoin__Cong => (setunion__Cong => (setunionsingleton => ! [X6 : $i] : ((singleton @ X6) => ! [X0 : $i] : ((in @ X0 @ X6) => ((setunion @ X6) = X0))))))))),
% 1.51/1.29    inference(negated_conjecture,[status(cth)],[f7])).
% 1.51/1.29  thf(f7,conjecture,(
% 1.51/1.29    uniqinunit => (in__Cong => (setadjoin__Cong => (setunion__Cong => (setunionsingleton => ! [X6 : $i] : ((singleton @ X6) => ! [X0 : $i] : ((in @ X0 @ X6) => ((setunion @ X6) = X0)))))))),
% 1.51/1.29    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',theeq)).
% 1.51/1.29  thf(f107,plain,(
% 1.51/1.29    ( ! [X0 : $i] : (((setunion @ (setadjoin @ X0 @ emptyset)) = X0)) )),
% 1.51/1.29    inference(trivial_inequality_removal,[status(thm)],[f89])).
% 1.51/1.29  thf(f89,plain,(
% 1.51/1.29    ( ! [X0 : $i] : (($true != $true) | ((setunion @ (setadjoin @ X0 @ emptyset)) = X0)) )),
% 1.51/1.29    inference(definition_unfolding,[status(thm)],[f66,f73])).
% 1.51/1.29  thf(f73,plain,(
% 1.51/1.29    (setunionsingleton = $true)),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f48])).
% 1.51/1.29  thf(f66,plain,(
% 1.51/1.29    ( ! [X0 : $i] : (((setunion @ (setadjoin @ X0 @ emptyset)) = X0) | (setunionsingleton != $true)) )),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f45])).
% 1.51/1.29  thf(f45,plain,(
% 1.51/1.29    (! [X0 : $i] : ((setunion @ (setadjoin @ X0 @ emptyset)) = X0) | (setunionsingleton != $true)) & ((setunionsingleton = $true) | (sK8 != (setunion @ (setadjoin @ sK8 @ emptyset))))),
% 1.51/1.29    inference(skolemisation,[status(esa),new_symbols(skolem,[sK8])],[f43,f44])).
% 1.51/1.29  thf(f44,plain,(
% 1.51/1.29    ? [X1 : $i] : ((setunion @ (setadjoin @ X1 @ emptyset)) != X1) => (sK8 != (setunion @ (setadjoin @ sK8 @ emptyset)))),
% 1.51/1.29    introduced(definition,[],[choice_axiom])).
% 1.51/1.29  thf(f43,plain,(
% 1.51/1.29    (! [X0 : $i] : ((setunion @ (setadjoin @ X0 @ emptyset)) = X0) | (setunionsingleton != $true)) & ((setunionsingleton = $true) | ? [X1 : $i] : ((setunion @ (setadjoin @ X1 @ emptyset)) != X1))),
% 1.51/1.29    inference(rectify,[status(thm)],[f42])).
% 1.51/1.29  thf(f42,plain,(
% 1.51/1.29    (! [X0 : $i] : ((setunion @ (setadjoin @ X0 @ emptyset)) = X0) | (setunionsingleton != $true)) & ((setunionsingleton = $true) | ? [X0 : $i] : ((setunion @ (setadjoin @ X0 @ emptyset)) != X0))),
% 1.51/1.29    inference(nnf_transformation,[status(thm)],[f16])).
% 1.51/1.29  thf(f16,plain,(
% 1.51/1.29    ! [X0 : $i] : ((setunion @ (setadjoin @ X0 @ emptyset)) = X0) <=> (setunionsingleton = $true)),
% 1.51/1.29    inference(fool_elimination,[status(thm)],[f5])).
% 1.51/1.29  thf(f5,axiom,(
% 1.51/1.29    (! [X0 : $i] : ((setunion @ (setadjoin @ X0 @ emptyset)) = X0) = setunionsingleton)),
% 1.51/1.29    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',setunionsingleton)).
% 1.51/1.29  thf(f72,plain,(
% 1.51/1.29    (sK10 != (setunion @ sK9))),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f48])).
% 1.51/1.29  thf(f114,plain,(
% 1.51/1.29    (sK16 = sK10)),
% 1.51/1.29    inference(trivial_inequality_removal,[status(thm)],[f112])).
% 1.51/1.29  thf(f112,plain,(
% 1.51/1.29    ($true != $true) | (sK16 = sK10)),
% 1.51/1.29    inference(superposition,[status(thm)],[f111,f71])).
% 1.51/1.29  thf(f71,plain,(
% 1.51/1.29    ($true = (in @ sK10 @ sK9))),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f48])).
% 1.51/1.29  thf(f111,plain,(
% 1.51/1.29    ( ! [X0 : $i] : (($true != (in @ X0 @ sK9)) | (sK16 = X0)) )),
% 1.51/1.29    inference(superposition,[status(thm)],[f108,f106])).
% 1.51/1.29  thf(f108,plain,(
% 1.51/1.29    ( ! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) != $true) | (X0 = X1)) )),
% 1.51/1.29    inference(trivial_inequality_removal,[status(thm)],[f86])).
% 1.51/1.29  thf(f86,plain,(
% 1.51/1.29    ( ! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) != $true) | (X0 = X1) | ($true != $true)) )),
% 1.51/1.29    inference(definition_unfolding,[status(thm)],[f64,f74])).
% 1.51/1.29  thf(f74,plain,(
% 1.51/1.29    (uniqinunit = $true)),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f48])).
% 1.51/1.29  thf(f64,plain,(
% 1.51/1.29    ( ! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) != $true) | (X0 = X1) | (uniqinunit != $true)) )),
% 1.51/1.29    inference(cnf_transformation,[status(thm)],[f41])).
% 1.51/1.29  thf(f41,plain,(
% 1.51/1.29    (! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) != $true) | (X0 = X1)) | (uniqinunit != $true)) & ((uniqinunit = $true) | (($true = (in @ sK6 @ (setadjoin @ sK7 @ emptyset))) & (sK7 != sK6)))),
% 1.51/1.29    inference(skolemisation,[status(esa),new_symbols(skolem,[sK6,sK7])],[f39,f40])).
% 1.51/1.29  thf(f40,plain,(
% 1.51/1.29    ? [X2 : $i,X3 : $i] : (($true = (in @ X2 @ (setadjoin @ X3 @ emptyset))) & (X2 != X3)) => (($true = (in @ sK6 @ (setadjoin @ sK7 @ emptyset))) & (sK7 != sK6))),
% 1.51/1.29    introduced(definition,[],[choice_axiom])).
% 1.51/1.29  thf(f39,plain,(
% 1.51/1.29    (! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) != $true) | (X0 = X1)) | (uniqinunit != $true)) & ((uniqinunit = $true) | ? [X2 : $i,X3 : $i] : (($true = (in @ X2 @ (setadjoin @ X3 @ emptyset))) & (X2 != X3)))),
% 1.51/1.29    inference(rectify,[status(thm)],[f38])).
% 1.51/1.29  thf(f38,plain,(
% 1.51/1.29    (! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) != $true) | (X0 = X1)) | (uniqinunit != $true)) & ((uniqinunit = $true) | ? [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) = $true) & (X0 != X1)))),
% 1.51/1.29    inference(nnf_transformation,[status(thm)],[f26])).
% 1.51/1.29  thf(f26,plain,(
% 1.51/1.29    ! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) != $true) | (X0 = X1)) <=> (uniqinunit = $true)),
% 1.51/1.29    inference(ennf_transformation,[status(thm)],[f20])).
% 1.51/1.29  thf(f20,plain,(
% 1.51/1.29    (uniqinunit = $true) <=> ! [X0 : $i,X1 : $i] : (((in @ X0 @ (setadjoin @ X1 @ emptyset)) = $true) => (X0 = X1))),
% 1.51/1.29    inference(fool_elimination,[status(thm)],[f19])).
% 1.51/1.29  thf(f19,plain,(
% 1.51/1.29    (! [X0 : $i,X1 : $i] : ((in @ X0 @ (setadjoin @ X1 @ emptyset)) => (X0 = X1)) = uniqinunit)),
% 1.51/1.29    inference(rectify,[status(thm)],[f1])).
% 1.51/1.29  thf(f1,axiom,(
% 1.51/1.29    (! [X0 : $i,X1 : $i] : ((in @ X0 @ (setadjoin @ X1 @ emptyset)) => (X0 = X1)) = uniqinunit)),
% 1.51/1.29    file('/export/starexec/sandbox2/tmp/tmp.X3mwlUDXaZ/DTF2THF_26023.p',uniqinunit)).
% 1.51/1.29  % SZS output end Proof for DTF2THF_26023
% 1.51/1.29  % (26293)------------------------------
% 1.51/1.29  % (26293)Version: Vampire 4.8 (commit 7b44b1c2f on 2025-07-15 09:50:17 +0100)
% 1.51/1.29  % (26293)Termination reason: Refutation
% 1.51/1.29  
% 1.51/1.29  % (26293)Memory used [KB]: 5500
% 1.51/1.29  % (26293)Time elapsed: 0.007 s
% 1.51/1.29  % (26293)Instructions burned: 5 (million)
% 1.51/1.29  % (26293)------------------------------
% 1.51/1.30  % (26293)------------------------------
% 1.51/1.30  % (26286)Success in time 0.022 s
%------------------------------------------------------------------------------