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DT2H2X---1.9.5.THM-Ref.s

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%------------------------------------------------------------------------------
% File     : DT2H2X---1.9.5
% Problem  : SEU615^2 : TPTP v9.2.1. Released v3.7.0.
% Transfm  : none
% Format   : tptp:raw
% Command  : /export/starexec/sandbox/solver/bin/run_DT2H2X /export/starexec/sandbox/benchmark/theBenchmark.p 300

% Computer : n018.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 09:35:38 AM UTC 2026

% Result   : Theorem 1.50s 1.28s
% Output   : Refutation 1.50s
% Verified : 
% SZS Type : Refutation
%            Derivation depth      :   25
%            Number of leaves      :    8
% Syntax   : Number of formulae    :   49 (  20 unt;   0 typ;   4 def)
%            Number of atoms       :  390 (  83 equ;   0 cnn)
%            Maximal formula atoms :    6 (   7 avg)
%            Number of connectives :  662 (  76   ~;  33   |;  13   &; 388   @)
%                                         (   4 <=>; 123  =>;   0  <=;   0 <~>)
%            Maximal formula depth :   12 (   5 avg)
%            Number of types       :    2 (   0 usr)
%            Number of type conns  :    0 (   0   >;   0   *;   0   +;   0  <<)
%            Number of symbols     :   15 (  11 usr;  11 con; 0-2 aty)
%                                         (  25  !!;   0  ??;   0 @@+;   0 @@-)
%            Number of variables   :  113 (  29   ^;  75   !;   9   ?; 113   :)

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

thf(func_def_1,type,
    symdiff: $i > $i > $i ).

thf(func_def_4,type,
    vEPSILON: 
      !>[X0: $tType] : ( ( X0 > $o ) > X0 ) ).

thf(f163,plain,
    $false,
    inference(avatar_sat_refutation,[status(thm)],[f91,f101,f159,f161,f162]) ).

thf(f162,plain,
    ~ spl3_13,
    inference(avatar_split_clause,[status(thm)],[f17,f146]) ).

thf(f146,definition,
    ( spl3_13
  <=> ( ( in @ sK1 @ sK0 )
      = $true ) ),
    introduced(definition,[new_symbols(naming,[spl3_13])],[avatar_definition]) ).

thf(f17,plain,
    ( ( in @ sK1 @ sK0 )
   != $true ),
    inference(cnf_transformation,[status(thm)],[f13]) ).

thf(f13,plain,
    ( ( $true
      = ( in @ sK1 @ ( symdiff @ sK2 @ sK0 ) ) )
    & ( ( in @ sK1 @ sK0 )
     != $true )
    & ( $true
     != ( in @ sK1 @ sK2 ) )
    & ( symdiffE = $true ) ),
    inference(skolemisation,[status(esa),new_symbols(skolem,[sK0,sK1,sK2])],[f11,f12]) ).

thf(f12,plain,
    ( ? [X0: $i,X1: $i,X2: $i] :
        ( ( $true
          = ( in @ X1 @ ( symdiff @ X2 @ X0 ) ) )
        & ( $true
         != ( in @ X1 @ X0 ) )
        & ( $true
         != ( in @ X1 @ X2 ) ) )
   => ( ( $true
        = ( in @ sK1 @ ( symdiff @ sK2 @ sK0 ) ) )
      & ( ( in @ sK1 @ sK0 )
       != $true )
      & ( $true
       != ( in @ sK1 @ sK2 ) ) ) ),
    introduced(definition,[],[choice_axiom]) ).

thf(f11,plain,
    ( ? [X0: $i,X1: $i,X2: $i] :
        ( ( $true
          = ( in @ X1 @ ( symdiff @ X2 @ X0 ) ) )
        & ( $true
         != ( in @ X1 @ X0 ) )
        & ( $true
         != ( in @ X1 @ X2 ) ) )
    & ( symdiffE = $true ) ),
    inference(flattening,[status(thm)],[f10]) ).

thf(f10,plain,
    ( ? [X0: $i,X1: $i,X2: $i] :
        ( ( $true
          = ( in @ X1 @ ( symdiff @ X2 @ X0 ) ) )
        & ( $true
         != ( in @ X1 @ X0 ) )
        & ( $true
         != ( in @ X1 @ X2 ) ) )
    & ( symdiffE = $true ) ),
    inference(ennf_transformation,[status(thm)],[f9]) ).

thf(f9,plain,
    ~ ( ( symdiffE = $true )
     => ! [X0: $i,X1: $i,X2: $i] :
          ( ( $true
           != ( in @ X1 @ X2 ) )
         => ( ( $true
             != ( in @ X1 @ X0 ) )
           => ( $true
             != ( in @ X1 @ ( symdiff @ X2 @ X0 ) ) ) ) ) ),
    inference(flattening,[status(thm)],[f6]) ).

thf(f6,plain,
    ~ ( ( symdiffE = $true )
     => ! [X0: $i,X1: $i,X2: $i] :
          ( ( $true
           != ( in @ X1 @ X2 ) )
         => ( ( $true
             != ( in @ X1 @ X0 ) )
           => ( $true
             != ( in @ X1 @ ( symdiff @ X2 @ X0 ) ) ) ) ) ),
    inference(fool_elimination,[status(thm)],[f5]) ).

thf(f5,plain,
    ~ ( symdiffE
     => ! [X0: $i,X1: $i,X2: $i] :
          ( ~ ( in @ X1 @ X2 )
         => ( ~ ( in @ X1 @ X0 )
           => ~ ( in @ X1 @ ( symdiff @ X2 @ X0 ) ) ) ) ),
    inference(rectify,[status(thm)],[f3]) ).

thf(f3,negated_conjecture,
    ~ ( symdiffE
     => ! [X1: $i,X2: $i,X0: $i] :
          ( ~ ( in @ X2 @ X0 )
         => ( ~ ( in @ X2 @ X1 )
           => ~ ( in @ X2 @ ( symdiff @ X0 @ X1 ) ) ) ) ),
    inference(negated_conjecture,[status(cth)],[f2]) ).

thf(f2,conjecture,
    ( symdiffE
   => ! [X1: $i,X2: $i,X0: $i] :
        ( ~ ( in @ X2 @ X0 )
       => ( ~ ( in @ X2 @ X1 )
         => ~ ( in @ X2 @ ( symdiff @ X0 @ X1 ) ) ) ) ),
    file('/export/starexec/sandbox/tmp/tmp.JmWU9g9kXA/DTF2THF_25558.p',symdiffIneg2) ).

thf(f161,plain,
    ~ spl3_12,
    inference(avatar_split_clause,[status(thm)],[f16,f142]) ).

thf(f142,definition,
    ( spl3_12
  <=> ( $true
      = ( in @ sK1 @ sK2 ) ) ),
    introduced(definition,[new_symbols(naming,[spl3_12])],[avatar_definition]) ).

thf(f16,plain,
    ( $true
   != ( in @ sK1 @ sK2 ) ),
    inference(cnf_transformation,[status(thm)],[f13]) ).

thf(f159,plain,
    ( spl3_12
    | spl3_13
    | ~ spl3_10 ),
    inference(avatar_split_clause,[status(thm)],[f129,f89,f146,f142]) ).

thf(f89,definition,
    ( spl3_10
  <=> ! [X2: $i,X1: $i,X3: $i] :
        ( ( $true
          = ( in @ X2 @ X3 ) )
        | ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
          = $false )
        | ( ( in @ X2 @ X1 )
          = $true ) ) ),
    introduced(definition,[new_symbols(naming,[spl3_10])],[avatar_definition]) ).

thf(f129,plain,
    ( ( ( in @ sK1 @ sK0 )
      = $true )
    | ( $true
      = ( in @ sK1 @ sK2 ) )
    | ~ spl3_10 ),
    inference(trivial_inequality_removal,[status(thm)],[f125]) ).

thf(f125,plain,
    ( ( $true
      = ( in @ sK1 @ sK2 ) )
    | ( ( in @ sK1 @ sK0 )
      = $true )
    | ( $true = $false )
    | ~ spl3_10 ),
    inference(superposition,[status(thm)],[f90,f18]) ).

thf(f18,plain,
    ( $true
    = ( in @ sK1 @ ( symdiff @ sK2 @ sK0 ) ) ),
    inference(cnf_transformation,[status(thm)],[f13]) ).

thf(f90,plain,
    ( ! [X2: $i,X3: $i,X1: $i] :
        ( ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
          = $false )
        | ( ( in @ X2 @ X1 )
          = $true )
        | ( $true
          = ( in @ X2 @ X3 ) ) )
    | ~ spl3_10 ),
    inference(avatar_component_clause,[status(thm)],[f89]) ).

thf(f101,plain,
    ~ spl3_7,
    inference(avatar_contradiction_clause,[status(thm)],[f100]) ).

thf(f100,plain,
    ( $false
    | ~ spl3_7 ),
    inference(equality_resolution,[status(thm)],[f97]) ).

thf(f97,plain,
    ( ! [X0: $o] : ( $false != X0 )
    | ~ spl3_7 ),
    inference(superposition,[status(thm)],[f4,f78]) ).

thf(f78,plain,
    ( ! [X4: $o] : ( $true = X4 )
    | ~ spl3_7 ),
    inference(avatar_component_clause,[status(thm)],[f77]) ).

thf(f77,definition,
    ( spl3_7
  <=> ! [X4: $o] : ( $true = X4 ) ),
    introduced(definition,[new_symbols(naming,[spl3_7])],[avatar_definition]) ).

thf(f4,plain,
    $true != $false,
    introduced(definition,[],[fool_axiom]) ).

thf(f91,plain,
    ( spl3_10
    | spl3_7 ),
    inference(avatar_split_clause,[status(thm)],[f37,f77,f89]) ).

thf(f37,plain,
    ! [X2: $i,X3: $i,X1: $i,X4: $o] :
      ( ( $true
        = ( in @ X2 @ X3 ) )
      | ( ( in @ X2 @ X1 )
        = $true )
      | ( $true = X4 )
      | ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false ) ),
    inference(binary_proxy_clausification,[status(thm)],[f33]) ).

thf(f33,plain,
    ! [X2: $i,X3: $i,X1: $i,X4: $o] :
      ( ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false )
      | ( ( ( in @ X2 @ X3 )
         => X4 )
        = $false )
      | ( $true = X4 )
      | ( ( in @ X2 @ X1 )
        = $true ) ),
    inference(binary_proxy_clausification,[status(thm)],[f32]) ).

thf(f32,plain,
    ! [X2: $i,X3: $i,X1: $i,X4: $o] :
      ( ( $true = X4 )
      | ( ( ~ ( in @ X2 @ X1 )
         => ( ( in @ X2 @ X3 )
           => X4 ) )
        = $false )
      | ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false )
      | ( ( in @ X2 @ X1 )
        = $true ) ),
    inference(binary_proxy_clausification,[status(thm)],[f30]) ).

thf(f30,plain,
    ! [X2: $i,X3: $i,X1: $i,X4: $o] :
      ( ( $true = X4 )
      | ( ( ( in @ X2 @ X1 )
         => ( ~ ( in @ X2 @ X3 )
           => X4 ) )
        = $false )
      | ( ( ~ ( in @ X2 @ X1 )
         => ( ( in @ X2 @ X3 )
           => X4 ) )
        = $false )
      | ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false ) ),
    inference(binary_proxy_clausification,[status(thm)],[f29]) ).

thf(f29,plain,
    ! [X2: $i,X3: $i,X1: $i,X4: $o] :
      ( ( $true
        = ( ( ~ ( in @ X2 @ X1 )
           => ( ( in @ X2 @ X3 )
             => X4 ) )
         => X4 ) )
      | ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false )
      | ( ( ( in @ X2 @ X1 )
         => ( ~ ( in @ X2 @ X3 )
           => X4 ) )
        = $false ) ),
    inference(binary_proxy_clausification,[status(thm)],[f28]) ).

thf(f28,plain,
    ! [X2: $i,X3: $i,X1: $i,X4: $o] :
      ( ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false )
      | ( $true
        = ( ( ( in @ X2 @ X1 )
           => ( ~ ( in @ X2 @ X3 )
             => X4 ) )
         => ( ( ~ ( in @ X2 @ X1 )
             => ( ( in @ X2 @ X3 )
               => X4 ) )
           => X4 ) ) ) ),
    inference(beta_eta_normalization,[status(thm)],[f27]) ).

thf(f27,plain,
    ! [X2: $i,X3: $i,X1: $i,X4: $o] :
      ( ( $true
        = ( ^ [Y0: $o] :
              ( ( ( in @ X2 @ X1 )
               => ( ~ ( in @ X2 @ X3 )
                 => Y0 ) )
             => ( ( ~ ( in @ X2 @ X1 )
                 => ( ( in @ X2 @ X3 )
                   => Y0 ) )
               => Y0 ) )
          @ X4 ) )
      | ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false ) ),
    inference(pi_clausification,[status(thm)],[f26]) ).

thf(f26,plain,
    ! [X2: $i,X3: $i,X1: $i] :
      ( ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
        = $false )
      | ( $true
        = ( !! @ $o
          @ ^ [Y0: $o] :
              ( ( ( in @ X2 @ X1 )
               => ( ~ ( in @ X2 @ X3 )
                 => Y0 ) )
             => ( ( ~ ( in @ X2 @ X1 )
                 => ( ( in @ X2 @ X3 )
                   => Y0 ) )
               => Y0 ) ) ) ) ),
    inference(binary_proxy_clausification,[status(thm)],[f25]) ).

thf(f25,plain,
    ! [X2: $i,X3: $i,X1: $i] :
      ( $true
      = ( ( in @ X2 @ ( symdiff @ X1 @ X3 ) )
       => ( !! @ $o
          @ ^ [Y0: $o] :
              ( ( ( in @ X2 @ X1 )
               => ( ~ ( in @ X2 @ X3 )
                 => Y0 ) )
             => ( ( ~ ( in @ X2 @ X1 )
                 => ( ( in @ X2 @ X3 )
                   => Y0 ) )
               => Y0 ) ) ) ) ),
    inference(beta_eta_normalization,[status(thm)],[f24]) ).

thf(f24,plain,
    ! [X2: $i,X3: $i,X1: $i] :
      ( $true
      = ( ^ [Y0: $i] :
            ( ( in @ X2 @ ( symdiff @ X1 @ Y0 ) )
           => ( !! @ $o
              @ ^ [Y1: $o] :
                  ( ( ( in @ X2 @ X1 )
                   => ( ~ ( in @ X2 @ Y0 )
                     => Y1 ) )
                 => ( ( ~ ( in @ X2 @ X1 )
                     => ( ( in @ X2 @ Y0 )
                       => Y1 ) )
                   => Y1 ) ) ) )
        @ X3 ) ),
    inference(pi_clausification,[status(thm)],[f23]) ).

thf(f23,plain,
    ! [X2: $i,X1: $i] :
      ( $true
      = ( !! @ $i
        @ ^ [Y0: $i] :
            ( ( in @ X2 @ ( symdiff @ X1 @ Y0 ) )
           => ( !! @ $o
              @ ^ [Y1: $o] :
                  ( ( ( in @ X2 @ X1 )
                   => ( ~ ( in @ X2 @ Y0 )
                     => Y1 ) )
                 => ( ( ~ ( in @ X2 @ X1 )
                     => ( ( in @ X2 @ Y0 )
                       => Y1 ) )
                   => Y1 ) ) ) ) ) ),
    inference(beta_eta_normalization,[status(thm)],[f22]) ).

thf(f22,plain,
    ! [X2: $i,X1: $i] :
      ( $true
      = ( ^ [Y0: $i] :
            ( !! @ $i
            @ ^ [Y1: $i] :
                ( ( in @ Y0 @ ( symdiff @ X1 @ Y1 ) )
               => ( !! @ $o
                  @ ^ [Y2: $o] :
                      ( ( ( in @ Y0 @ X1 )
                       => ( ~ ( in @ Y0 @ Y1 )
                         => Y2 ) )
                     => ( ( ~ ( in @ Y0 @ X1 )
                         => ( ( in @ Y0 @ Y1 )
                           => Y2 ) )
                       => Y2 ) ) ) ) )
        @ X2 ) ),
    inference(pi_clausification,[status(thm)],[f21]) ).

thf(f21,plain,
    ! [X1: $i] :
      ( $true
      = ( !! @ $i
        @ ^ [Y0: $i] :
            ( !! @ $i
            @ ^ [Y1: $i] :
                ( ( in @ Y0 @ ( symdiff @ X1 @ Y1 ) )
               => ( !! @ $o
                  @ ^ [Y2: $o] :
                      ( ( ( in @ Y0 @ X1 )
                       => ( ~ ( in @ Y0 @ Y1 )
                         => Y2 ) )
                     => ( ( ~ ( in @ Y0 @ X1 )
                         => ( ( in @ Y0 @ Y1 )
                           => Y2 ) )
                       => Y2 ) ) ) ) ) ) ),
    inference(beta_eta_normalization,[status(thm)],[f20]) ).

thf(f20,plain,
    ! [X1: $i] :
      ( $true
      = ( ^ [Y0: $i] :
            ( !! @ $i
            @ ^ [Y1: $i] :
                ( !! @ $i
                @ ^ [Y2: $i] :
                    ( ( in @ Y1 @ ( symdiff @ Y0 @ Y2 ) )
                   => ( !! @ $o
                      @ ^ [Y3: $o] :
                          ( ( ( in @ Y1 @ Y0 )
                           => ( ~ ( in @ Y1 @ Y2 )
                             => Y3 ) )
                         => ( ( ~ ( in @ Y1 @ Y0 )
                             => ( ( in @ Y1 @ Y2 )
                               => Y3 ) )
                           => Y3 ) ) ) ) ) )
        @ X1 ) ),
    inference(pi_clausification,[status(thm)],[f19]) ).

thf(f19,plain,
    ( $true
    = ( !! @ $i
      @ ^ [Y0: $i] :
          ( !! @ $i
          @ ^ [Y1: $i] :
              ( !! @ $i
              @ ^ [Y2: $i] :
                  ( ( in @ Y1 @ ( symdiff @ Y0 @ Y2 ) )
                 => ( !! @ $o
                    @ ^ [Y3: $o] :
                        ( ( ( in @ Y1 @ Y0 )
                         => ( ~ ( in @ Y1 @ Y2 )
                           => Y3 ) )
                       => ( ( ~ ( in @ Y1 @ Y0 )
                           => ( ( in @ Y1 @ Y2 )
                             => Y3 ) )
                         => Y3 ) ) ) ) ) ) ) ),
    inference(definition_unfolding,[status(thm)],[f15,f14]) ).

thf(f14,plain,
    ( symdiffE
    = ( !! @ $i
      @ ^ [Y0: $i] :
          ( !! @ $i
          @ ^ [Y1: $i] :
              ( !! @ $i
              @ ^ [Y2: $i] :
                  ( ( in @ Y1 @ ( symdiff @ Y0 @ Y2 ) )
                 => ( !! @ $o
                    @ ^ [Y3: $o] :
                        ( ( ( in @ Y1 @ Y0 )
                         => ( ~ ( in @ Y1 @ Y2 )
                           => Y3 ) )
                       => ( ( ~ ( in @ Y1 @ Y0 )
                           => ( ( in @ Y1 @ Y2 )
                             => Y3 ) )
                         => Y3 ) ) ) ) ) ) ) ),
    inference(cnf_transformation,[status(thm)],[f8]) ).

thf(f8,plain,
    ( symdiffE
    = ( !! @ $i
      @ ^ [Y0: $i] :
          ( !! @ $i
          @ ^ [Y1: $i] :
              ( !! @ $i
              @ ^ [Y2: $i] :
                  ( ( in @ Y1 @ ( symdiff @ Y0 @ Y2 ) )
                 => ( !! @ $o
                    @ ^ [Y3: $o] :
                        ( ( ( in @ Y1 @ Y0 )
                         => ( ~ ( in @ Y1 @ Y2 )
                           => Y3 ) )
                       => ( ( ~ ( in @ Y1 @ Y0 )
                           => ( ( in @ Y1 @ Y2 )
                             => Y3 ) )
                         => Y3 ) ) ) ) ) ) ) ),
    inference(fool_elimination,[status(thm)],[f7]) ).

thf(f7,plain,
    ( symdiffE
    = ( ! [X0: $i,X1: $i,X2: $i] :
          ( ( in @ X1 @ ( symdiff @ X2 @ X0 ) )
         => ! [X3: $o] :
              ( ( ( in @ X1 @ X2 )
               => ( ~ ( in @ X1 @ X0 )
                 => X3 ) )
             => ( ( ~ ( in @ X1 @ X2 )
                 => ( ( in @ X1 @ X0 )
                   => X3 ) )
               => X3 ) ) ) ) ),
    inference(rectify,[status(thm)],[f1]) ).

thf(f1,axiom,
    ( symdiffE
    = ( ! [X1: $i,X2: $i,X0: $i] :
          ( ( in @ X2 @ ( symdiff @ X0 @ X1 ) )
         => ! [X3: $o] :
              ( ( ( in @ X2 @ X0 )
               => ( ~ ( in @ X2 @ X1 )
                 => X3 ) )
             => ( ( ~ ( in @ X2 @ X0 )
                 => ( ( in @ X2 @ X1 )
                   => X3 ) )
               => X3 ) ) ) ) ),
    file('/export/starexec/sandbox/tmp/tmp.JmWU9g9kXA/DTF2THF_25558.p',symdiffE) ).

thf(f15,plain,
    symdiffE = $true,
    inference(cnf_transformation,[status(thm)],[f13]) ).

%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.00/0.12  % Problem  : SEU615^2 : TPTP v9.2.1. Released v3.7.0.
% 0.12/0.13  % Command  : /export/starexec/sandbox/solver/bin/run_DT2H2X /export/starexec/sandbox/benchmark/theBenchmark.p 300
% 0.15/0.34  % Computer : n018.cluster.edu
% 0.15/0.34  % Model    : x86_64 x86_64
% 0.15/0.34  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.15/0.34  % Memory   : 8042.1875MB
% 0.15/0.34  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.15/0.34  % CPULimit : 300
% 0.15/0.34  % WCLimit  : 300
% 0.15/0.34  % DateTime : Tue Feb 24 12:29:01 EST 2026
% 0.15/0.34  % CPUTime  : 
% 0.15/0.34  Running /export/starexec/sandbox/solver/bin/run_DT2H2X /export/starexec/sandbox/benchmark/theBenchmark.p 300
% 0.20/0.45  ---- Original DTF file ---
% 0.20/0.45  thf(spec,logic,$$dhol).
% 0.20/0.45  %------------------------------------------------------------------------------
% 0.20/0.45  % File     : SEU615^2 : TPTP v9.2.1. Released v3.7.0.
% 0.20/0.45  % Domain   : Set Theory
% 0.20/0.45  % Problem  : Preliminary Notions - Operations on Sets - Symmetric Difference
% 0.20/0.45  % Version  : Especial > Reduced > Especial.
% 0.20/0.45  % English  : (! A:i.! B:i.! x:i.~(in x A) -> ~(in x B) -> ~(in x
% 0.20/0.45  %            (symdiff A B)))
% 0.20/0.45  
% 0.20/0.45  % Refs     : [Bro08] Brown (2008), Email to G. Sutcliffe
% 0.20/0.45  % Source   : [Bro08]
% 0.20/0.45  % Names    : ZFC117l [Bro08]
% 0.20/0.45  
% 0.20/0.45  % Status   : Theorem
% 0.20/0.45  % Rating   : 0.00 v8.2.0, 0.08 v8.1.0, 0.00 v6.0.0, 0.14 v5.5.0, 0.17 v5.4.0, 0.20 v5.3.0, 0.40 v5.2.0, 0.20 v4.1.0, 0.00 v3.7.0
% 0.20/0.45  % Syntax   : Number of formulae    :    5 (   1 unt;   3 typ;   1 def)
% 0.20/0.45  %            Number of atoms       :   11 (   1 equ;   0 cnn)
% 0.20/0.45  %            Maximal formula atoms :    4 (   5 avg)
% 0.20/0.45  %            Number of connectives :   35 (   5   ~;   0   |;   0   &;  20   @)
% 0.20/0.45  %                                         (   0 <=>;  10  =>;   0  <=;   0 <~>)
% 0.20/0.45  %            Maximal formula depth :   11 (   6 avg)
% 0.20/0.45  %            Number of types       :    2 (   0 usr)
% 0.20/0.45  %            Number of type conns  :    4 (   4   >;   0   *;   0   +;   0  <<)
% 0.20/0.45  %            Number of symbols     :    4 (   3 usr;   1 con; 0-2 aty)
% 0.20/0.45  %            Number of variables   :    7 (   0   ^;   7   !;   0   ?;   7   :)
% 0.20/0.45  % SPC      : TH0_THM_EQU_NAR
% 0.20/0.45  
% 0.20/0.45  % Comments : http://mathgate.info/detsetitem.php?id=493
% 0.20/0.45  %------------------------------------------------------------------------------
% 0.20/0.45  thf(in_type,type,
% 0.20/0.45      in: $i > $i > $o ).
% 0.20/0.45  
% 0.20/0.45  thf(symdiff_type,type,
% 0.20/0.45      symdiff: $i > $i > $i ).
% 0.20/0.45  
% 0.20/0.45  thf(symdiffE_type,type,
% 0.20/0.45      symdiffE: $o ).
% 0.20/0.45  
% 0.20/0.45  thf(symdiffE,definition,
% 0.20/0.45      ( symdiffE
% 0.20/0.45      = ( ! [A: $i,B: $i,Xx: $i] :
% 0.20/0.45            ( ( in @ Xx @ ( symdiff @ A @ B ) )
% 0.20/0.45           => ! [Xphi: $o] :
% 0.20/0.45                ( ( ( in @ Xx @ A )
% 0.20/0.45                 => ( ~ ( in @ Xx @ B )
% 0.20/0.45                   => Xphi ) )
% 0.20/0.45               => ( ( ~ ( in @ Xx @ A )
% 0.20/0.45                   => ( ( in @ Xx @ B )
% 0.20/0.45                     => Xphi ) )
% 0.20/0.45                 => Xphi ) ) ) ) ) ).
% 0.20/0.45  
% 0.20/0.45  thf(symdiffIneg2,conjecture,
% 0.20/0.45      ( symdiffE
% 0.20/0.45     => ! [A: $i,B: $i,Xx: $i] :
% 0.20/0.45          ( ~ ( in @ Xx @ A )
% 0.20/0.45         => ( ~ ( in @ Xx @ B )
% 0.20/0.45           => ~ ( in @ Xx @ ( symdiff @ A @ B ) ) ) ) ) ).
% 0.20/0.45  
% 0.20/0.45  %------------------------------------------------------------------------------
% 0.20/0.45  ------------------------
% 1.50/1.25  ---- Embedded in THF ---
% 1.50/1.25  %%% This output was generated by embedproblem, version 1.9.5 (library version 1.9).
% 1.50/1.25  %%% Generated on Tue Feb 24 12:29:01 EST 2026
% 1.50/1.25  %%% using '$$dhol' embedding, version 1.3.0.
% 1.50/1.25  %%% Logic specification used:
% 1.50/1.25  %%% thf(spec, logic, $$dhol).
% 1.50/1.25  
% 1.50/1.25  % SZS output start ListOfTHF for /export/starexec/sandbox/tmp/tmp.JmWU9g9kXA/DTF2DTF25558.p
% See solution above
% 1.50/1.25  ------------------------
% 1.50/1.26  ---- Cleaned THF ---
% 1.50/1.26  thf(in_type,type,
% 1.50/1.26      in: $i > $i > $o ).
% 1.50/1.26  
% 1.50/1.26  thf(symdiff_type,type,
% 1.50/1.26      symdiff: $i > $i > $i ).
% 1.50/1.26  
% 1.50/1.26  thf(symdiffE_type,type,
% 1.50/1.26      symdiffE: $o ).
% 1.50/1.26  
% 1.50/1.26  thf(symdiffE,definition,
% 1.50/1.26      ( symdiffE
% 1.50/1.26      = ( ! [A: $i,B: $i,Xx: $i] :
% 1.50/1.26            ( ( in @ Xx @ ( symdiff @ A @ B ) )
% 1.50/1.26           => ! [Xphi: $o] :
% 1.50/1.26                ( ( ( in @ Xx @ A )
% 1.50/1.26                 => ( ~ ( in @ Xx @ B )
% 1.50/1.26                   => Xphi ) )
% 1.50/1.26               => ( ( ~ ( in @ Xx @ A )
% 1.50/1.26                   => ( ( in @ Xx @ B )
% 1.50/1.26                     => Xphi ) )
% 1.50/1.26                 => Xphi ) ) ) ) ) ).
% 1.50/1.26  
% 1.50/1.26  thf(symdiffIneg2,conjecture,
% 1.50/1.26      ( symdiffE
% 1.50/1.26     => ! [A: $i,B: $i,Xx: $i] :
% 1.50/1.26          ( ~ ( in @ Xx @ A )
% 1.50/1.26         => ( ~ ( in @ Xx @ B )
% 1.50/1.26           => ~ ( in @ Xx @ ( symdiff @ A @ B ) ) ) ) ) ).
% 1.50/1.26  ------------------------
% 1.50/1.27  % (25842)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_25558 for (2999ds/27Mi)
% 1.50/1.27  % (25840)lrs+1002_1:8_bd=off:fd=off:hud=10:tnu=1:i=183:si=on:rtra=on_0 on DTF2THF_25558 for (2999ds/183Mi)
% 1.50/1.28  % (25842)First to succeed.
% 1.50/1.28  % (25840)Also succeeded, but the first one will report.
% 1.50/1.28  % (25842)Refutation found. Thanks to Tanya!
% 1.50/1.28  % SZS status Theorem for DTF2THF_25558
% 1.50/1.28  % SZS output start Proof for DTF2THF_25558
% 1.50/1.28  thf(func_def_0, type, in: $i > $i > $o).
% 1.50/1.28  thf(func_def_1, type, symdiff: $i > $i > $i).
% 1.50/1.28  thf(func_def_4, type, vEPSILON: !>[X0: $tType]:((X0 > $o) > X0)).
% 1.50/1.28  thf(f163,plain,(
% 1.50/1.28    $false),
% 1.50/1.28    inference(avatar_sat_refutation,[status(thm)],[f91,f101,f159,f161,f162])).
% 1.50/1.28  thf(f162,plain,(
% 1.50/1.28    ~spl3_13),
% 1.50/1.28    inference(avatar_split_clause,[status(thm)],[f17,f146])).
% 1.50/1.28  thf(f146,definition,(
% 1.50/1.28    spl3_13 <=> ((in @ sK1 @ sK0) = $true)),
% 1.50/1.28    introduced(definition,[new_symbols(naming,[spl3_13])],[avatar_definition])).
% 1.50/1.28  thf(f17,plain,(
% 1.50/1.28    ((in @ sK1 @ sK0) != $true)),
% 1.50/1.28    inference(cnf_transformation,[status(thm)],[f13])).
% 1.50/1.28  thf(f13,plain,(
% 1.50/1.28    (($true = (in @ sK1 @ (symdiff @ sK2 @ sK0))) & ((in @ sK1 @ sK0) != $true) & ($true != (in @ sK1 @ sK2))) & (symdiffE = $true)),
% 1.50/1.28    inference(skolemisation,[status(esa),new_symbols(skolem,[sK0,sK1,sK2])],[f11,f12])).
% 1.50/1.28  thf(f12,plain,(
% 1.50/1.28    ? [X0 : $i,X1 : $i,X2 : $i] : (($true = (in @ X1 @ (symdiff @ X2 @ X0))) & ($true != (in @ X1 @ X0)) & ($true != (in @ X1 @ X2))) => (($true = (in @ sK1 @ (symdiff @ sK2 @ sK0))) & ((in @ sK1 @ sK0) != $true) & ($true != (in @ sK1 @ sK2)))),
% 1.50/1.28    introduced(definition,[],[choice_axiom])).
% 1.50/1.28  thf(f11,plain,(
% 1.50/1.28    ? [X0 : $i,X1 : $i,X2 : $i] : (($true = (in @ X1 @ (symdiff @ X2 @ X0))) & ($true != (in @ X1 @ X0)) & ($true != (in @ X1 @ X2))) & (symdiffE = $true)),
% 1.50/1.28    inference(flattening,[status(thm)],[f10])).
% 1.50/1.28  thf(f10,plain,(
% 1.50/1.28    ? [X0 : $i,X1 : $i,X2 : $i] : ((($true = (in @ X1 @ (symdiff @ X2 @ X0))) & ($true != (in @ X1 @ X0))) & ($true != (in @ X1 @ X2))) & (symdiffE = $true)),
% 1.50/1.28    inference(ennf_transformation,[status(thm)],[f9])).
% 1.50/1.28  thf(f9,plain,(
% 1.50/1.28    ~((symdiffE = $true) => ! [X0 : $i,X1 : $i,X2 : $i] : (($true != (in @ X1 @ X2)) => (($true != (in @ X1 @ X0)) => ($true != (in @ X1 @ (symdiff @ X2 @ X0))))))),
% 1.50/1.28    inference(flattening,[status(thm)],[f6])).
% 1.50/1.28  thf(f6,plain,(
% 1.50/1.28    ~((symdiffE = $true) => ! [X0 : $i,X1 : $i,X2 : $i] : (~($true = (in @ X1 @ X2)) => (~($true = (in @ X1 @ X0)) => ~($true = (in @ X1 @ (symdiff @ X2 @ X0))))))),
% 1.50/1.28    inference(fool_elimination,[status(thm)],[f5])).
% 1.50/1.28  thf(f5,plain,(
% 1.50/1.28    ~(symdiffE => ! [X0 : $i,X1 : $i,X2 : $i] : (~(in @ X1 @ X2) => (~(in @ X1 @ X0) => ~(in @ X1 @ (symdiff @ X2 @ X0)))))),
% 1.50/1.28    inference(rectify,[status(thm)],[f3])).
% 1.50/1.28  thf(f3,negated_conjecture,(
% 1.50/1.28    ~(symdiffE => ! [X1 : $i,X2 : $i,X0 : $i] : (~(in @ X2 @ X0) => (~(in @ X2 @ X1) => ~(in @ X2 @ (symdiff @ X0 @ X1)))))),
% 1.50/1.28    inference(negated_conjecture,[status(cth)],[f2])).
% 1.50/1.28  thf(f2,conjecture,(
% 1.50/1.28    symdiffE => ! [X1 : $i,X2 : $i,X0 : $i] : (~(in @ X2 @ X0) => (~(in @ X2 @ X1) => ~(in @ X2 @ (symdiff @ X0 @ X1))))),
% 1.50/1.28    file('/export/starexec/sandbox/tmp/tmp.JmWU9g9kXA/DTF2THF_25558.p',symdiffIneg2)).
% 1.50/1.28  thf(f161,plain,(
% 1.50/1.28    ~spl3_12),
% 1.50/1.28    inference(avatar_split_clause,[status(thm)],[f16,f142])).
% 1.50/1.28  thf(f142,definition,(
% 1.50/1.28    spl3_12 <=> ($true = (in @ sK1 @ sK2))),
% 1.50/1.28    introduced(definition,[new_symbols(naming,[spl3_12])],[avatar_definition])).
% 1.50/1.28  thf(f16,plain,(
% 1.50/1.28    ($true != (in @ sK1 @ sK2))),
% 1.50/1.28    inference(cnf_transformation,[status(thm)],[f13])).
% 1.50/1.28  thf(f159,plain,(
% 1.50/1.28    spl3_12 | spl3_13 | ~spl3_10),
% 1.50/1.28    inference(avatar_split_clause,[status(thm)],[f129,f89,f146,f142])).
% 1.50/1.28  thf(f89,definition,(
% 1.50/1.28    spl3_10 <=> ! [X2 : $i,X1 : $i,X3 : $i] : (($true = (in @ X2 @ X3)) | ((in @ X2 @ (symdiff @ X1 @ X3)) = $false) | ((in @ X2 @ X1) = $true))),
% 1.50/1.28    introduced(definition,[new_symbols(naming,[spl3_10])],[avatar_definition])).
% 1.50/1.28  thf(f129,plain,(
% 1.50/1.28    ((in @ sK1 @ sK0) = $true) | ($true = (in @ sK1 @ sK2)) | ~spl3_10),
% 1.50/1.28    inference(trivial_inequality_removal,[status(thm)],[f125])).
% 1.50/1.28  thf(f125,plain,(
% 1.50/1.28    ($true = (in @ sK1 @ sK2)) | ((in @ sK1 @ sK0) = $true) | ($true = $false) | ~spl3_10),
% 1.50/1.28    inference(superposition,[status(thm)],[f90,f18])).
% 1.50/1.28  thf(f18,plain,(
% 1.50/1.28    ($true = (in @ sK1 @ (symdiff @ sK2 @ sK0)))),
% 1.50/1.28    inference(cnf_transformation,[status(thm)],[f13])).
% 1.50/1.28  thf(f90,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i] : (((in @ X2 @ (symdiff @ X1 @ X3)) = $false) | ((in @ X2 @ X1) = $true) | ($true = (in @ X2 @ X3))) ) | ~spl3_10),
% 1.50/1.28    inference(avatar_component_clause,[status(thm)],[f89])).
% 1.50/1.28  thf(f101,plain,(
% 1.50/1.28    ~spl3_7),
% 1.50/1.28    inference(avatar_contradiction_clause,[status(thm)],[f100])).
% 1.50/1.28  thf(f100,plain,(
% 1.50/1.28    $false | ~spl3_7),
% 1.50/1.28    inference(equality_resolution,[status(thm)],[f97])).
% 1.50/1.28  thf(f97,plain,(
% 1.50/1.28    ( ! [X0 : $o] : (($false != X0)) ) | ~spl3_7),
% 1.50/1.28    inference(superposition,[status(thm)],[f4,f78])).
% 1.50/1.28  thf(f78,plain,(
% 1.50/1.28    ( ! [X4 : $o] : (($true = X4)) ) | ~spl3_7),
% 1.50/1.28    inference(avatar_component_clause,[status(thm)],[f77])).
% 1.50/1.28  thf(f77,definition,(
% 1.50/1.28    spl3_7 <=> ! [X4 : $o] : ($true = X4)),
% 1.50/1.28    introduced(definition,[new_symbols(naming,[spl3_7])],[avatar_definition])).
% 1.50/1.28  thf(f4,plain,(
% 1.50/1.28    ($true != $false)),
% 1.50/1.28    introduced(definition,[],[fool_axiom])).
% 1.50/1.28  thf(f91,plain,(
% 1.50/1.28    spl3_10 | spl3_7),
% 1.50/1.28    inference(avatar_split_clause,[status(thm)],[f37,f77,f89])).
% 1.50/1.28  thf(f37,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i,X4 : $o] : (($true = (in @ X2 @ X3)) | ((in @ X2 @ X1) = $true) | ($true = X4) | ((in @ X2 @ (symdiff @ X1 @ X3)) = $false)) )),
% 1.50/1.28    inference(binary_proxy_clausification,[status(thm)],[f33])).
% 1.50/1.28  thf(f33,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i,X4 : $o] : (((in @ X2 @ (symdiff @ X1 @ X3)) = $false) | (((in @ X2 @ X3) => X4) = $false) | ($true = X4) | ((in @ X2 @ X1) = $true)) )),
% 1.50/1.28    inference(binary_proxy_clausification,[status(thm)],[f32])).
% 1.50/1.28  thf(f32,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i,X4 : $o] : (($true = X4) | (((~ (in @ X2 @ X1)) => ((in @ X2 @ X3) => X4)) = $false) | ((in @ X2 @ (symdiff @ X1 @ X3)) = $false) | ((in @ X2 @ X1) = $true)) )),
% 1.50/1.28    inference(binary_proxy_clausification,[status(thm)],[f30])).
% 1.50/1.28  thf(f30,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i,X4 : $o] : (($true = X4) | (((in @ X2 @ X1) => ((~ (in @ X2 @ X3)) => X4)) = $false) | (((~ (in @ X2 @ X1)) => ((in @ X2 @ X3) => X4)) = $false) | ((in @ X2 @ (symdiff @ X1 @ X3)) = $false)) )),
% 1.50/1.28    inference(binary_proxy_clausification,[status(thm)],[f29])).
% 1.50/1.28  thf(f29,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i,X4 : $o] : (($true = (((~ (in @ X2 @ X1)) => ((in @ X2 @ X3) => X4)) => X4)) | ((in @ X2 @ (symdiff @ X1 @ X3)) = $false) | (((in @ X2 @ X1) => ((~ (in @ X2 @ X3)) => X4)) = $false)) )),
% 1.50/1.28    inference(binary_proxy_clausification,[status(thm)],[f28])).
% 1.50/1.28  thf(f28,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i,X4 : $o] : (((in @ X2 @ (symdiff @ X1 @ X3)) = $false) | ($true = (((in @ X2 @ X1) => ((~ (in @ X2 @ X3)) => X4)) => (((~ (in @ X2 @ X1)) => ((in @ X2 @ X3) => X4)) => X4)))) )),
% 1.50/1.28    inference(beta_eta_normalization,[status(thm)],[f27])).
% 1.50/1.28  thf(f27,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i,X4 : $o] : (($true = ((^[Y0 : $o]: (((in @ X2 @ X1) => ((~ (in @ X2 @ X3)) => Y0)) => (((~ (in @ X2 @ X1)) => ((in @ X2 @ X3) => Y0)) => Y0))) @ X4)) | ((in @ X2 @ (symdiff @ X1 @ X3)) = $false)) )),
% 1.50/1.28    inference(pi_clausification,[status(thm)],[f26])).
% 1.50/1.28  thf(f26,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i] : (((in @ X2 @ (symdiff @ X1 @ X3)) = $false) | ($true = (!! @ $o @ (^[Y0 : $o]: (((in @ X2 @ X1) => ((~ (in @ X2 @ X3)) => Y0)) => (((~ (in @ X2 @ X1)) => ((in @ X2 @ X3) => Y0)) => Y0)))))) )),
% 1.50/1.28    inference(binary_proxy_clausification,[status(thm)],[f25])).
% 1.50/1.28  thf(f25,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i] : (($true = ((in @ X2 @ (symdiff @ X1 @ X3)) => (!! @ $o @ (^[Y0 : $o]: (((in @ X2 @ X1) => ((~ (in @ X2 @ X3)) => Y0)) => (((~ (in @ X2 @ X1)) => ((in @ X2 @ X3) => Y0)) => Y0))))))) )),
% 1.50/1.28    inference(beta_eta_normalization,[status(thm)],[f24])).
% 1.50/1.28  thf(f24,plain,(
% 1.50/1.28    ( ! [X2 : $i,X3 : $i,X1 : $i] : (($true = ((^[Y0 : $i]: ((in @ X2 @ (symdiff @ X1 @ Y0)) => (!! @ $o @ (^[Y1 : $o]: (((in @ X2 @ X1) => ((~ (in @ X2 @ Y0)) => Y1)) => (((~ (in @ X2 @ X1)) => ((in @ X2 @ Y0) => Y1)) => Y1)))))) @ X3))) )),
% 1.50/1.28    inference(pi_clausification,[status(thm)],[f23])).
% 1.50/1.28  thf(f23,plain,(
% 1.50/1.28    ( ! [X2 : $i,X1 : $i] : (($true = (!! @ $i @ (^[Y0 : $i]: ((in @ X2 @ (symdiff @ X1 @ Y0)) => (!! @ $o @ (^[Y1 : $o]: (((in @ X2 @ X1) => ((~ (in @ X2 @ Y0)) => Y1)) => (((~ (in @ X2 @ X1)) => ((in @ X2 @ Y0) => Y1)) => Y1))))))))) )),
% 1.50/1.28    inference(beta_eta_normalization,[status(thm)],[f22])).
% 1.50/1.28  thf(f22,plain,(
% 1.50/1.28    ( ! [X2 : $i,X1 : $i] : (($true = ((^[Y0 : $i]: (!! @ $i @ (^[Y1 : $i]: ((in @ Y0 @ (symdiff @ X1 @ Y1)) => (!! @ $o @ (^[Y2 : $o]: (((in @ Y0 @ X1) => ((~ (in @ Y0 @ Y1)) => Y2)) => (((~ (in @ Y0 @ X1)) => ((in @ Y0 @ Y1) => Y2)) => Y2)))))))) @ X2))) )),
% 1.50/1.28    inference(pi_clausification,[status(thm)],[f21])).
% 1.50/1.28  thf(f21,plain,(
% 1.50/1.28    ( ! [X1 : $i] : (($true = (!! @ $i @ (^[Y0 : $i]: (!! @ $i @ (^[Y1 : $i]: ((in @ Y0 @ (symdiff @ X1 @ Y1)) => (!! @ $o @ (^[Y2 : $o]: (((in @ Y0 @ X1) => ((~ (in @ Y0 @ Y1)) => Y2)) => (((~ (in @ Y0 @ X1)) => ((in @ Y0 @ Y1) => Y2)) => Y2))))))))))) )),
% 1.50/1.28    inference(beta_eta_normalization,[status(thm)],[f20])).
% 1.50/1.28  thf(f20,plain,(
% 1.50/1.28    ( ! [X1 : $i] : (($true = ((^[Y0 : $i]: (!! @ $i @ (^[Y1 : $i]: (!! @ $i @ (^[Y2 : $i]: ((in @ Y1 @ (symdiff @ Y0 @ Y2)) => (!! @ $o @ (^[Y3 : $o]: (((in @ Y1 @ Y0) => ((~ (in @ Y1 @ Y2)) => Y3)) => (((~ (in @ Y1 @ Y0)) => ((in @ Y1 @ Y2) => Y3)) => Y3)))))))))) @ X1))) )),
% 1.50/1.28    inference(pi_clausification,[status(thm)],[f19])).
% 1.50/1.28  thf(f19,plain,(
% 1.50/1.28    ($true = (!! @ $i @ (^[Y0 : $i]: (!! @ $i @ (^[Y1 : $i]: (!! @ $i @ (^[Y2 : $i]: ((in @ Y1 @ (symdiff @ Y0 @ Y2)) => (!! @ $o @ (^[Y3 : $o]: (((in @ Y1 @ Y0) => ((~ (in @ Y1 @ Y2)) => Y3)) => (((~ (in @ Y1 @ Y0)) => ((in @ Y1 @ Y2) => Y3)) => Y3))))))))))))),
% 1.50/1.28    inference(definition_unfolding,[status(thm)],[f15,f14])).
% 1.50/1.28  thf(f14,plain,(
% 1.50/1.28    (symdiffE = (!! @ $i @ (^[Y0 : $i]: (!! @ $i @ (^[Y1 : $i]: (!! @ $i @ (^[Y2 : $i]: ((in @ Y1 @ (symdiff @ Y0 @ Y2)) => (!! @ $o @ (^[Y3 : $o]: (((in @ Y1 @ Y0) => ((~ (in @ Y1 @ Y2)) => Y3)) => (((~ (in @ Y1 @ Y0)) => ((in @ Y1 @ Y2) => Y3)) => Y3))))))))))))),
% 1.50/1.28    inference(cnf_transformation,[status(thm)],[f8])).
% 1.50/1.28  thf(f8,plain,(
% 1.50/1.28    (symdiffE = (!! @ $i @ (^[Y0 : $i]: (!! @ $i @ (^[Y1 : $i]: (!! @ $i @ (^[Y2 : $i]: ((in @ Y1 @ (symdiff @ Y0 @ Y2)) => (!! @ $o @ (^[Y3 : $o]: (((in @ Y1 @ Y0) => ((~ (in @ Y1 @ Y2)) => Y3)) => (((~ (in @ Y1 @ Y0)) => ((in @ Y1 @ Y2) => Y3)) => Y3))))))))))))),
% 1.50/1.28    inference(fool_elimination,[status(thm)],[f7])).
% 1.50/1.28  thf(f7,plain,(
% 1.50/1.28    (symdiffE = ! [X0 : $i,X1 : $i,X2 : $i] : ((in @ X1 @ (symdiff @ X2 @ X0)) => ! [X3 : $o] : (((in @ X1 @ X2) => (~(in @ X1 @ X0) => X3)) => ((~(in @ X1 @ X2) => ((in @ X1 @ X0) => X3)) => X3))))),
% 1.50/1.28    inference(rectify,[status(thm)],[f1])).
% 1.50/1.28  thf(f1,axiom,(
% 1.50/1.28    (symdiffE = ! [X1 : $i,X2 : $i,X0 : $i] : ((in @ X2 @ (symdiff @ X0 @ X1)) => ! [X3 : $o] : (((in @ X2 @ X0) => (~(in @ X2 @ X1) => X3)) => ((~(in @ X2 @ X0) => ((in @ X2 @ X1) => X3)) => X3))))),
% 1.50/1.28    file('/export/starexec/sandbox/tmp/tmp.JmWU9g9kXA/DTF2THF_25558.p',symdiffE)).
% 1.50/1.28  thf(f15,plain,(
% 1.50/1.28    (symdiffE = $true)),
% 1.50/1.28    inference(cnf_transformation,[status(thm)],[f13])).
% 1.50/1.28  % SZS output end Proof for DTF2THF_25558
% 1.50/1.28  % (25842)------------------------------
% 1.50/1.28  % (25842)Version: Vampire 4.8 (commit 7b44b1c2f on 2025-07-15 09:50:17 +0100)
% 1.50/1.28  % (25842)Termination reason: Refutation
% 1.50/1.28  
% 1.50/1.28  % (25842)Memory used [KB]: 5628
% 1.50/1.28  % (25842)Time elapsed: 0.006 s
% 1.50/1.28  % (25842)Instructions burned: 10 (million)
% 1.50/1.28  % (25842)------------------------------
% 1.50/1.28  % (25842)------------------------------
% 1.50/1.28  % (25839)Success in time 0.016 s
%------------------------------------------------------------------------------