%------------------------------------------------------------------------------
% File     : GEO228+3 : TPTP v9.0.0. Released v4.0.0.
% Domain   : Geometry (Constructive)
% Problem  : Obervability of equal or opposite direction
% Version  : [vPl98] axioms.
% English  :

% Refs     : [vPl98] von Plato (1998), A Constructive Theory of Ordered Aff
%          : [ROK06] Raths et al. (2006), The ILTP Problem Library for Intu
%          : [Rat07] Raths (2007), Email to Geoff Sutcliffe
% Source   : [Rat07]
% Names    : Therorem 3.2 [vPl98]

% Status   : CounterSatisfiable
% Rating   : 0.40 v9.0.0, 0.33 v8.2.0, 0.00 v7.4.0, 0.33 v7.3.0, 0.00 v7.0.0, 0.33 v6.4.0, 0.00 v6.2.0, 0.22 v6.1.0, 0.10 v6.0.0, 0.00 v5.5.0, 0.29 v5.4.0, 0.80 v5.3.0, 0.85 v5.2.0, 0.62 v5.0.0, 0.56 v4.1.0, 0.33 v4.0.1, 0.67 v4.0.0
% Syntax   : Number of formulae    :   37 (   6 unt;   0 def)
%            Number of atoms       :  112 (   0 equ)
%            Maximal formula atoms :   10 (   3 avg)
%            Number of connectives :   87 (  12   ~;  23   |;  24   &)
%                                         (  11 <=>;  17  =>;   0  <=;   0 <~>)
%            Maximal formula depth :   13 (   5 avg)
%            Maximal term depth    :    3 (   1 avg)
%            Number of predicates  :   19 (  19 usr;   0 prp; 1-4 aty)
%            Number of functors    :    4 (   4 usr;   0 con; 1-2 aty)
%            Number of variables   :   83 (  83   !;   0   ?)
% SPC      : FOF_CSA_RFO_NEQ

% Comments :
%------------------------------------------------------------------------------
include('Axioms/GEO009+0.ax').
%------------------------------------------------------------------------------
fof(con,conjecture,
    ! [L,M] :
      ( parallel_lines(L,M)
    <=> ( equally_directed_lines(L,M)
        | equally_directed_opposite_lines(L,M) ) ) ).

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