%--------------------------------------------------------------------------
% File     : LAT001-4 : TPTP v9.0.0. Released .0.
% Domain   : Lattice Theory
% Axioms   : Lattice theory unique complementation (equality) axioms
% Version  : [McC05] (equality) axioms.
% English  :

% Refs     : [McC05] McCune (2005), Email to Geoff Sutcliffe
% Source   : [McC05]
% Names    :

% Status   : Satisfiable
% Syntax   : Number of clauses     :    3 (   2 unt;   0 nHn;   1 RR)
%            Number of literals    :    5 (   5 equ;   2 neg)
%            Maximal clause size   :    3 (   1 avg)
%            Maximal term depth    :    3 (   1 avg)
%            Number of predicates  :    1 (   0 usr;   0 prp; 2-2 aty)
%            Number of functors    :    5 (   5 usr;   2 con; 0-2 aty)
%            Number of variables   :    4 (   0 sgn)
% SPC      : 

% Comments : Requires LAT001-0.ax
%--------------------------------------------------------------------------
%----Unique complementation
cnf(complement_join,axiom,
    join(X,complement(X)) = one ).

cnf(complement_meet,axiom,
    meet(X,complement(X)) = zero ).

cnf(meet_join_complement,axiom,
    ( meet(X,Y) != zero
    | join(X,Y) != one
    | complement(X) = Y ) ).

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