%--------------------------------------------------------------------------
% File     : BOO015-1 : TPTP v8.2.0. Bugfixed v1.2.1.
% Domain   : Boolean Algebra
% Problem  : DeMorgan for inverse and sum (X^-1 + Y^-1) = (X * Y)^-1
% Version  : [MOW76] axioms.
% English  :

% Refs     : [MOW76] McCharen et al. (1976), Problems and Experiments for a
%          : [Ver92] Veroff (1992), Email to G. Sutcliffe
% Source   : [Ver92]
% Names    : DeMorgan's Laws [Ver92]

% Status   : Unsatisfiable
% Rating   : 0.31 v8.2.0, 0.33 v8.1.0, 0.22 v7.5.0, 0.10 v7.4.0, 0.22 v7.2.0, 0.25 v7.1.0, 0.29 v7.0.0, 0.14 v6.3.0, 0.17 v6.2.0, 0.00 v6.1.0, 0.20 v6.0.0, 0.44 v5.5.0, 0.69 v5.4.0, 0.73 v5.3.0, 0.75 v5.2.0, 0.38 v5.1.0, 0.29 v4.1.0, 0.33 v4.0.1, 0.00 v4.0.0, 0.17 v3.5.0, 0.00 v3.3.0, 0.14 v3.1.0, 0.33 v2.7.0, 0.17 v2.6.0, 0.43 v2.5.0, 0.40 v2.4.0, 0.33 v2.3.0, 0.17 v2.2.1, 0.75 v2.2.0, 0.67 v2.1.0, 0.67 v2.0.0
% Syntax   : Number of clauses     :   25 (  13 unt;   0 nHn;  15 RR)
%            Number of literals    :   63 (   3 equ;  39 neg)
%            Maximal clause size   :    5 (   2 avg)
%            Maximal term depth    :    2 (   1 avg)
%            Number of predicates  :    3 (   2 usr;   0 prp; 2-3 aty)
%            Number of functors    :    9 (   9 usr;   6 con; 0-2 aty)
%            Number of variables   :   82 (   0 sgn)
% SPC      : CNF_UNS_RFO_SEQ_HRN

% Comments :
% Bugfixes : v1.2.1 - Clause x_times_y fixed.
%--------------------------------------------------------------------------
%----Include boolean algebra axioms
include('Axioms/BOO002-0.ax').
%--------------------------------------------------------------------------
cnf(x_times_y,negated_conjecture,
    product(x,y,x_times_y) ).

cnf(x_inverse_plus_y_inverse,negated_conjecture,
    sum(inverse(x),inverse(y),x_inverse_plus_y_inverse) ).

cnf(prove_equation,negated_conjecture,
    inverse(x_times_y) != x_inverse_plus_y_inverse ).

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