%------------------------------------------------------------------------------
% File     : LCL680+1.001 : TPTP v9.0.0. Released v4.0.0.
% Domain   : Logic Calculi (Modal Logic)
% Problem  : In S4, in backward search find a way through box and dia, size 1
% Version  : Especial.
% English  :

% Refs     : [BHS00] Balsiger et al. (2000), A Benchmark Method for the Pro
%          : [Kam08] Kaminski (2008), Email to G. Sutcliffe
% Source   : [Kam08]
% Names    : s4_md_p [BHS00]

% Status   : Theorem
% Rating   : 0.00 v5.5.0, 0.11 v5.4.0, 0.00 v5.3.0, 0.09 v5.2.0, 0.00 v4.0.0
% Syntax   : Number of formulae    :    1 (   0 unt;   0 def)
%            Number of atoms       :    2 (   0 equ)
%            Maximal formula atoms :    2 (   2 avg)
%            Number of connectives :    4 (   3   ~;   1   |;   0   &)
%                                         (   0 <=>;   0  =>;   0  <=;   0 <~>)
%            Maximal formula depth :    6 (   6 avg)
%            Maximal term depth    :    1 (   1 avg)
%            Number of predicates  :    1 (   1 usr;   0 prp; 1-1 aty)
%            Number of functors    :    0 (   0 usr;   0 con; --- aty)
%            Number of variables   :    1 (   0   !;   1   ?)
% SPC      : FOF_THM_EPR_NEQ

% Comments : A naive relational encoding of the modal logic problem into
%            first-order logic.
%------------------------------------------------------------------------------

fof(main,conjecture,
    ~ ? [X] :
        ~ ( ~ p1(X)
          | p1(X) ) ).

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