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Z3---4.15.1.UNS-Prf.s

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%------------------------------------------------------------------------------
% File     : Z3---4.15.1
% Problem  : COM004-1 : TPTP v9.0.0. Released v1.1.0.
% Transfm  : none
% Format   : tptp
% Command  : run_E %s %d THM

% Computer : n007.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 : Sat Jun 21 05:00:56 AM UTC 2025

% Result   : Unsatisfiable 0.18s 0.37s
% Output   : Proof 0.18s
% Verified : 
% SZS Type : Refutation
%            Derivation depth      :    8
%            Number of leaves      :   27
% Syntax   : Number of formulae    :   65 (  33 unt;   0 typ;   0 def)
%            Number of atoms       :  316 (  10 equ)
%            Maximal formula atoms :   20 (   4 avg)
%            Number of connectives :  433 ( 205   ~; 193   |;   0   &)
%                                         (  35 <=>;   0  =>;   0  <=;   0 <~>)
%            Maximal formula depth :   15 (   5 avg)
%            Maximal term depth    :    3 (   1 avg)
%            Number of FOOLs       :   23 (  23 fml;   0 var)
%            Number of types       :    2 (   0 usr)
%            Number of type conns  :    0 (   0   >;   0   *;   0   +;   0  <<)
%            Number of predicates  :    9 (   7 usr;   1 prp; 0-3 aty)
%            Number of functors    :   10 (  10 usr;   5 con; 0-2 aty)
%            Number of variables   :  156 ( 141   !;   0   ?; 156   :)

% Comments : 
%------------------------------------------------------------------------------
tff(failure_node_type,type,
    failure_node: ( $i * $i ) > $o ).

tff(or_type,type,
    or: ( $i * $i ) > $i ).

tff(empty_type,type,
    empty: $i ).

tff(parent_of_type,type,
    parent_of: ( $i * $i ) > $i ).

tff(right_child_of_type,type,
    right_child_of: $i > $i ).

tff(n_type,type,
    n: $i ).

tff(left_child_of_type,type,
    left_child_of: $i > $i ).

tff(negate_type,type,
    negate: $i > $i ).

tff(atom_type,type,
    atom: $i ).

tff(n_right_type,type,
    n_right: $i ).

tff(n_left_type,type,
    n_left: $i ).

tff(siblings_type,type,
    siblings: ( $i * $i ) > $o ).

tff(contradictory_type,type,
    contradictory: ( $i * $i ) > $o ).

tff(1,plain,
    ( ( n_right = right_child_of(n) )
  <=> ( n_right = right_child_of(n) ) ),
    inference(rewrite,[status(thm)],[]) ).

tff(2,axiom,
    n_right = right_child_of(n),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',n_right_equals_right_child_of_n) ).

tff(3,plain,
    n_right = right_child_of(n),
    inference(modus_ponens,[status(thm)],[2,1]) ).

tff(4,plain,
    right_child_of(n) = n_right,
    inference(symmetry,[status(thm)],[3]) ).

tff(5,plain,
    ( failure_node(right_child_of(n),or(empty,negate(atom)))
  <=> failure_node(n_right,or(empty,negate(atom))) ),
    inference(monotonicity,[status(thm)],[4]) ).

tff(6,plain,
    ( failure_node(n_right,or(empty,negate(atom)))
  <=> failure_node(right_child_of(n),or(empty,negate(atom))) ),
    inference(symmetry,[status(thm)],[5]) ).

tff(7,plain,
    ( failure_node(n_right,or(empty,negate(atom)))
  <=> failure_node(n_right,or(empty,negate(atom))) ),
    inference(rewrite,[status(thm)],[]) ).

tff(8,axiom,
    failure_node(n_right,or(empty,negate(atom))),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',n_right_is_not_atom) ).

tff(9,plain,
    failure_node(n_right,or(empty,negate(atom))),
    inference(modus_ponens,[status(thm)],[8,7]) ).

tff(10,plain,
    failure_node(right_child_of(n),or(empty,negate(atom))),
    inference(modus_ponens,[status(thm)],[9,6]) ).

tff(11,plain,
    ( ( n_left = left_child_of(n) )
  <=> ( n_left = left_child_of(n) ) ),
    inference(rewrite,[status(thm)],[]) ).

tff(12,axiom,
    n_left = left_child_of(n),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',n_left_equals_left_child_of_n) ).

tff(13,plain,
    n_left = left_child_of(n),
    inference(modus_ponens,[status(thm)],[12,11]) ).

tff(14,plain,
    left_child_of(n) = n_left,
    inference(symmetry,[status(thm)],[13]) ).

tff(15,plain,
    ( failure_node(left_child_of(n),or(empty,atom))
  <=> failure_node(n_left,or(empty,atom)) ),
    inference(monotonicity,[status(thm)],[14]) ).

tff(16,plain,
    ( failure_node(n_left,or(empty,atom))
  <=> failure_node(left_child_of(n),or(empty,atom)) ),
    inference(symmetry,[status(thm)],[15]) ).

tff(17,plain,
    ( failure_node(n_left,or(empty,atom))
  <=> failure_node(n_left,or(empty,atom)) ),
    inference(rewrite,[status(thm)],[]) ).

tff(18,axiom,
    failure_node(n_left,or(empty,atom)),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',n_left_is_atom) ).

tff(19,plain,
    failure_node(n_left,or(empty,atom)),
    inference(modus_ponens,[status(thm)],[18,17]) ).

tff(20,plain,
    failure_node(left_child_of(n),or(empty,atom)),
    inference(modus_ponens,[status(thm)],[19,16]) ).

tff(21,plain,
    ^ [X: $i] :
      refl(( siblings(left_child_of(X),right_child_of(X))
      <=> siblings(left_child_of(X),right_child_of(X)) )),
    inference(bind,[status(th)],[]) ).

tff(22,plain,
    ( ! [X: $i] : siblings(left_child_of(X),right_child_of(X))
  <=> ! [X: $i] : siblings(left_child_of(X),right_child_of(X)) ),
    inference(quant_intro,[status(thm)],[21]) ).

tff(23,plain,
    ( ! [X: $i] : siblings(left_child_of(X),right_child_of(X))
  <=> ! [X: $i] : siblings(left_child_of(X),right_child_of(X)) ),
    inference(rewrite,[status(thm)],[]) ).

tff(24,axiom,
    ! [X: $i] : siblings(left_child_of(X),right_child_of(X)),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',n_left_and_n_right_are_siblings) ).

tff(25,plain,
    ! [X: $i] : siblings(left_child_of(X),right_child_of(X)),
    inference(modus_ponens,[status(thm)],[24,23]) ).

tff(26,plain,
    ! [X: $i] : siblings(left_child_of(X),right_child_of(X)),
    inference(skolemize,[status(sab)],[25]) ).

tff(27,plain,
    ! [X: $i] : siblings(left_child_of(X),right_child_of(X)),
    inference(modus_ponens,[status(thm)],[26,22]) ).

tff(28,plain,
    ( ~ ! [X: $i] : siblings(left_child_of(X),right_child_of(X))
    | siblings(left_child_of(n),right_child_of(n)) ),
    inference(quant_inst,[status(thm)],[]) ).

tff(29,plain,
    siblings(left_child_of(n),right_child_of(n)),
    inference(unit_resolution,[status(thm)],[28,27]) ).

tff(30,plain,
    ^ [X: $i] :
      refl(( contradictory(X,negate(X))
      <=> contradictory(X,negate(X)) )),
    inference(bind,[status(th)],[]) ).

tff(31,plain,
    ( ! [X: $i] : contradictory(X,negate(X))
  <=> ! [X: $i] : contradictory(X,negate(X)) ),
    inference(quant_intro,[status(thm)],[30]) ).

tff(32,plain,
    ( ! [X: $i] : contradictory(X,negate(X))
  <=> ! [X: $i] : contradictory(X,negate(X)) ),
    inference(rewrite,[status(thm)],[]) ).

tff(33,axiom,
    ! [X: $i] : contradictory(X,negate(X)),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',x_contradicts_not_x) ).

tff(34,plain,
    ! [X: $i] : contradictory(X,negate(X)),
    inference(modus_ponens,[status(thm)],[33,32]) ).

tff(35,plain,
    ! [X: $i] : contradictory(X,negate(X)),
    inference(skolemize,[status(sab)],[34]) ).

tff(36,plain,
    ! [X: $i] : contradictory(X,negate(X)),
    inference(modus_ponens,[status(thm)],[35,31]) ).

tff(37,plain,
    ( ~ ! [X: $i] : contradictory(X,negate(X))
    | contradictory(atom,negate(atom)) ),
    inference(quant_inst,[status(thm)],[]) ).

tff(38,plain,
    contradictory(atom,negate(atom)),
    inference(unit_resolution,[status(thm)],[37,36]) ).

tff(39,plain,
    ^ [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
      refl(( ( ~ siblings(X,Y)
          | ~ contradictory(P,Q)
          | ~ failure_node(Y,or(D,Q))
          | ~ failure_node(X,or(C,P))
          | failure_node(parent_of(X,Y),or(C,D)) )
      <=> ( ~ siblings(X,Y)
          | ~ contradictory(P,Q)
          | ~ failure_node(Y,or(D,Q))
          | ~ failure_node(X,or(C,P))
          | failure_node(parent_of(X,Y),or(C,D)) ) )),
    inference(bind,[status(th)],[]) ).

tff(40,plain,
    ( ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
        ( ~ siblings(X,Y)
        | ~ contradictory(P,Q)
        | ~ failure_node(Y,or(D,Q))
        | ~ failure_node(X,or(C,P))
        | failure_node(parent_of(X,Y),or(C,D)) )
  <=> ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
        ( ~ siblings(X,Y)
        | ~ contradictory(P,Q)
        | ~ failure_node(Y,or(D,Q))
        | ~ failure_node(X,or(C,P))
        | failure_node(parent_of(X,Y),or(C,D)) ) ),
    inference(quant_intro,[status(thm)],[39]) ).

tff(41,plain,
    ( ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
        ( ~ siblings(X,Y)
        | ~ contradictory(P,Q)
        | ~ failure_node(Y,or(D,Q))
        | ~ failure_node(X,or(C,P))
        | failure_node(parent_of(X,Y),or(C,D)) )
  <=> ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
        ( ~ siblings(X,Y)
        | ~ contradictory(P,Q)
        | ~ failure_node(Y,or(D,Q))
        | ~ failure_node(X,or(C,P))
        | failure_node(parent_of(X,Y),or(C,D)) ) ),
    inference(rewrite,[status(thm)],[]) ).

tff(42,plain,
    ^ [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
      trans(monotonicity(trans(monotonicity(trans(monotonicity(rewrite(( ( failure_node(parent_of(X,Y),or(C,D))
                      | ~ failure_node(X,or(C,P)) )
                  <=> ( ~ failure_node(X,or(C,P))
                      | failure_node(parent_of(X,Y),or(C,D)) ) )),
                  ( ( failure_node(parent_of(X,Y),or(C,D))
                    | ~ failure_node(X,or(C,P))
                    | ~ failure_node(Y,or(D,Q)) )
                <=> ( ~ failure_node(X,or(C,P))
                    | failure_node(parent_of(X,Y),or(C,D))
                    | ~ failure_node(Y,or(D,Q)) ) )),
                rewrite(( ( ~ failure_node(X,or(C,P))
                    | failure_node(parent_of(X,Y),or(C,D))
                    | ~ failure_node(Y,or(D,Q)) )
                <=> ( ~ failure_node(Y,or(D,Q))
                    | ~ failure_node(X,or(C,P))
                    | failure_node(parent_of(X,Y),or(C,D)) ) )),
                ( ( failure_node(parent_of(X,Y),or(C,D))
                  | ~ failure_node(X,or(C,P))
                  | ~ failure_node(Y,or(D,Q)) )
              <=> ( ~ failure_node(Y,or(D,Q))
                  | ~ failure_node(X,or(C,P))
                  | failure_node(parent_of(X,Y),or(C,D)) ) )),
              ( ( failure_node(parent_of(X,Y),or(C,D))
                | ~ failure_node(X,or(C,P))
                | ~ failure_node(Y,or(D,Q))
                | ~ contradictory(P,Q) )
            <=> ( ~ failure_node(Y,or(D,Q))
                | ~ failure_node(X,or(C,P))
                | failure_node(parent_of(X,Y),or(C,D))
                | ~ contradictory(P,Q) ) )),
            rewrite(( ( ~ failure_node(Y,or(D,Q))
                | ~ failure_node(X,or(C,P))
                | failure_node(parent_of(X,Y),or(C,D))
                | ~ contradictory(P,Q) )
            <=> ( ~ contradictory(P,Q)
                | ~ failure_node(Y,or(D,Q))
                | ~ failure_node(X,or(C,P))
                | failure_node(parent_of(X,Y),or(C,D)) ) )),
            ( ( failure_node(parent_of(X,Y),or(C,D))
              | ~ failure_node(X,or(C,P))
              | ~ failure_node(Y,or(D,Q))
              | ~ contradictory(P,Q) )
          <=> ( ~ contradictory(P,Q)
              | ~ failure_node(Y,or(D,Q))
              | ~ failure_node(X,or(C,P))
              | failure_node(parent_of(X,Y),or(C,D)) ) )),
          ( ( failure_node(parent_of(X,Y),or(C,D))
            | ~ failure_node(X,or(C,P))
            | ~ failure_node(Y,or(D,Q))
            | ~ contradictory(P,Q)
            | ~ siblings(X,Y) )
        <=> ( ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D))
            | ~ siblings(X,Y) ) )),
        rewrite(( ( ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D))
            | ~ siblings(X,Y) )
        <=> ( ~ siblings(X,Y)
            | ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D)) ) )),
        ( ( failure_node(parent_of(X,Y),or(C,D))
          | ~ failure_node(X,or(C,P))
          | ~ failure_node(Y,or(D,Q))
          | ~ contradictory(P,Q)
          | ~ siblings(X,Y) )
      <=> ( ~ siblings(X,Y)
          | ~ contradictory(P,Q)
          | ~ failure_node(Y,or(D,Q))
          | ~ failure_node(X,or(C,P))
          | failure_node(parent_of(X,Y),or(C,D)) ) )),
    inference(bind,[status(th)],[]) ).

tff(43,plain,
    ( ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
        ( failure_node(parent_of(X,Y),or(C,D))
        | ~ failure_node(X,or(C,P))
        | ~ failure_node(Y,or(D,Q))
        | ~ contradictory(P,Q)
        | ~ siblings(X,Y) )
  <=> ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
        ( ~ siblings(X,Y)
        | ~ contradictory(P,Q)
        | ~ failure_node(Y,or(D,Q))
        | ~ failure_node(X,or(C,P))
        | failure_node(parent_of(X,Y),or(C,D)) ) ),
    inference(quant_intro,[status(thm)],[42]) ).

tff(44,axiom,
    ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
      ( failure_node(parent_of(X,Y),or(C,D))
      | ~ failure_node(X,or(C,P))
      | ~ failure_node(Y,or(D,Q))
      | ~ contradictory(P,Q)
      | ~ siblings(X,Y) ),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',make_node) ).

tff(45,plain,
    ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
      ( ~ siblings(X,Y)
      | ~ contradictory(P,Q)
      | ~ failure_node(Y,or(D,Q))
      | ~ failure_node(X,or(C,P))
      | failure_node(parent_of(X,Y),or(C,D)) ),
    inference(modus_ponens,[status(thm)],[44,43]) ).

tff(46,plain,
    ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
      ( ~ siblings(X,Y)
      | ~ contradictory(P,Q)
      | ~ failure_node(Y,or(D,Q))
      | ~ failure_node(X,or(C,P))
      | failure_node(parent_of(X,Y),or(C,D)) ),
    inference(modus_ponens,[status(thm)],[45,41]) ).

tff(47,plain,
    ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
      ( ~ siblings(X,Y)
      | ~ contradictory(P,Q)
      | ~ failure_node(Y,or(D,Q))
      | ~ failure_node(X,or(C,P))
      | failure_node(parent_of(X,Y),or(C,D)) ),
    inference(skolemize,[status(sab)],[46]) ).

tff(48,plain,
    ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
      ( ~ siblings(X,Y)
      | ~ contradictory(P,Q)
      | ~ failure_node(Y,or(D,Q))
      | ~ failure_node(X,or(C,P))
      | failure_node(parent_of(X,Y),or(C,D)) ),
    inference(modus_ponens,[status(thm)],[47,40]) ).

tff(49,plain,
    ( ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
            ( ~ siblings(X,Y)
            | ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D)) )
      | ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ contradictory(atom,negate(atom))
      | ~ siblings(left_child_of(n),right_child_of(n)) )
  <=> ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
            ( ~ siblings(X,Y)
            | ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D)) )
      | ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ contradictory(atom,negate(atom))
      | ~ siblings(left_child_of(n),right_child_of(n)) ) ),
    inference(rewrite,[status(thm)],[]) ).

tff(50,plain,
    ( ( ~ siblings(left_child_of(n),right_child_of(n))
      | ~ contradictory(atom,negate(atom))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty)) )
  <=> ( ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ contradictory(atom,negate(atom))
      | ~ siblings(left_child_of(n),right_child_of(n)) ) ),
    inference(rewrite,[status(thm)],[]) ).

tff(51,plain,
    ( ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
            ( ~ siblings(X,Y)
            | ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D)) )
      | ~ siblings(left_child_of(n),right_child_of(n))
      | ~ contradictory(atom,negate(atom))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty)) )
  <=> ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
            ( ~ siblings(X,Y)
            | ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D)) )
      | ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ contradictory(atom,negate(atom))
      | ~ siblings(left_child_of(n),right_child_of(n)) ) ),
    inference(monotonicity,[status(thm)],[50]) ).

tff(52,plain,
    ( ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
            ( ~ siblings(X,Y)
            | ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D)) )
      | ~ siblings(left_child_of(n),right_child_of(n))
      | ~ contradictory(atom,negate(atom))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty)) )
  <=> ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
            ( ~ siblings(X,Y)
            | ~ contradictory(P,Q)
            | ~ failure_node(Y,or(D,Q))
            | ~ failure_node(X,or(C,P))
            | failure_node(parent_of(X,Y),or(C,D)) )
      | ~ failure_node(left_child_of(n),or(empty,atom))
      | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty))
      | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
      | ~ contradictory(atom,negate(atom))
      | ~ siblings(left_child_of(n),right_child_of(n)) ) ),
    inference(transitivity,[status(thm)],[51,49]) ).

tff(53,plain,
    ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
          ( ~ siblings(X,Y)
          | ~ contradictory(P,Q)
          | ~ failure_node(Y,or(D,Q))
          | ~ failure_node(X,or(C,P))
          | failure_node(parent_of(X,Y),or(C,D)) )
    | ~ siblings(left_child_of(n),right_child_of(n))
    | ~ contradictory(atom,negate(atom))
    | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
    | ~ failure_node(left_child_of(n),or(empty,atom))
    | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty)) ),
    inference(quant_inst,[status(thm)],[]) ).

tff(54,plain,
    ( ~ ! [D: $i,Y: $i,Q: $i,P: $i,X: $i,C: $i] :
          ( ~ siblings(X,Y)
          | ~ contradictory(P,Q)
          | ~ failure_node(Y,or(D,Q))
          | ~ failure_node(X,or(C,P))
          | failure_node(parent_of(X,Y),or(C,D)) )
    | ~ failure_node(left_child_of(n),or(empty,atom))
    | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty))
    | ~ failure_node(right_child_of(n),or(empty,negate(atom)))
    | ~ contradictory(atom,negate(atom))
    | ~ siblings(left_child_of(n),right_child_of(n)) ),
    inference(modus_ponens,[status(thm)],[53,52]) ).

tff(55,plain,
    ( ~ failure_node(left_child_of(n),or(empty,atom))
    | failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty))
    | ~ failure_node(right_child_of(n),or(empty,negate(atom))) ),
    inference(unit_resolution,[status(thm)],[54,48,38,29]) ).

tff(56,plain,
    failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty)),
    inference(unit_resolution,[status(thm)],[55,20,10]) ).

tff(57,plain,
    ^ [Z: $i] :
      refl(( ~ failure_node(Z,or(empty,empty))
      <=> ~ failure_node(Z,or(empty,empty)) )),
    inference(bind,[status(th)],[]) ).

tff(58,plain,
    ( ! [Z: $i] : ~ failure_node(Z,or(empty,empty))
  <=> ! [Z: $i] : ~ failure_node(Z,or(empty,empty)) ),
    inference(quant_intro,[status(thm)],[57]) ).

tff(59,plain,
    ( ! [Z: $i] : ~ failure_node(Z,or(empty,empty))
  <=> ! [Z: $i] : ~ failure_node(Z,or(empty,empty)) ),
    inference(rewrite,[status(thm)],[]) ).

tff(60,axiom,
    ! [Z: $i] : ~ failure_node(Z,or(empty,empty)),
    file('/export/starexec/sandbox/benchmark/theBenchmark.p',goal_is_there_an_empty_node) ).

tff(61,plain,
    ! [Z: $i] : ~ failure_node(Z,or(empty,empty)),
    inference(modus_ponens,[status(thm)],[60,59]) ).

tff(62,plain,
    ! [Z: $i] : ~ failure_node(Z,or(empty,empty)),
    inference(skolemize,[status(sab)],[61]) ).

tff(63,plain,
    ! [Z: $i] : ~ failure_node(Z,or(empty,empty)),
    inference(modus_ponens,[status(thm)],[62,58]) ).

tff(64,plain,
    ( ~ ! [Z: $i] : ~ failure_node(Z,or(empty,empty))
    | ~ failure_node(parent_of(left_child_of(n),right_child_of(n)),or(empty,empty)) ),
    inference(quant_inst,[status(thm)],[]) ).

tff(65,plain,
    $false,
    inference(unit_resolution,[status(thm)],[64,63,56]) ).

%------------------------------------------------------------------------------
%----ORIGINAL SYSTEM OUTPUT
% 0.03/0.12  % Problem    : COM004-1 : TPTP v9.0.0. Released v1.1.0.
% 0.03/0.12  % Command    : run_E %s %d THM
% 0.11/0.33  % Computer : n007.cluster.edu
% 0.11/0.33  % Model    : x86_64 x86_64
% 0.11/0.33  % CPU      : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
% 0.11/0.33  % Memory   : 8042.1875MB
% 0.11/0.33  % OS       : Linux 3.10.0-693.el7.x86_64
% 0.11/0.33  % CPULimit   : 300
% 0.11/0.33  % WCLimit    : 300
% 0.11/0.33  % DateTime   : Thu Jun 19 12:21:49 EDT 2025
% 0.11/0.33  % CPUTime    : 
% 0.18/0.37  % SZS status Unsatisfiable
% 0.18/0.37  % SZS output start Proof
% See solution above
% 0.18/0.38  % E exiting
%------------------------------------------------------------------------------