%--------------------------------------------------------------------------
% File     : SYN348+1 : TPTP v8.2.0. Released v2.0.0.
% Domain   : Syntactic
% Problem  : Church problem 46.17 (4)
% Version  : Especial.
% English  :

% Refs     : [Chu56] Church (1956), Introduction to Mathematical Logic I
% Source   : [Chu56]
% Names    : 46.17 (4) [Chu56]

% Status   : CounterSatisfiable
% Rating   : 0.00 v6.2.0, 0.11 v6.1.0, 0.00 v5.4.0, 0.20 v5.3.0, 0.15 v5.2.0, 0.12 v5.0.0, 0.00 v4.1.0, 0.17 v4.0.1, 0.00 v3.1.0, 0.17 v2.7.0, 0.33 v2.6.0, 0.25 v2.5.0, 0.33 v2.3.0, 0.67 v2.2.1, 0.00 v2.1.0
% Syntax   : Number of formulae    :    1 (   0 unt;   0 def)
%            Number of atoms       :    8 (   0 equ)
%            Maximal formula atoms :    8 (   8 avg)
%            Number of connectives :    7 (   0   ~;   0   |;   1   &)
%                                         (   6 <=>;   0  =>;   0  <=;   0 <~>)
%            Maximal formula depth :    9 (   9 avg)
%            Maximal term depth    :    1 (   1 avg)
%            Number of predicates  :    1 (   1 usr;   0 prp; 2-2 aty)
%            Number of functors    :    0 (   0 usr;   0 con; --- aty)
%            Number of variables   :    4 (   2   !;   2   ?)
% SPC      : FOF_CSA_RFO_NEQ

% Comments :
%--------------------------------------------------------------------------
fof(church_46_17_4,conjecture,
    ? [X1] :
    ! [X2] :
    ? [X3] :
    ! [X4] :
      ( ( ( ( big_f(X1,X4)
          <=> big_f(X4,X3) )
        <=> big_f(X3,X4) )
      <=> big_f(X4,X1) )
      & ( ( ( big_f(X2,X4)
          <=> big_f(X4,X3) )
        <=> big_f(X3,X4) )
      <=> big_f(X4,X2) ) ) ).

%--------------------------------------------------------------------------