%--------------------------------------------------------------------------
% File     : GRP002-0 : TPTP v9.0.0. Released v1.0.0.
% Domain   : Group Theory (Semigroups)
% Axioms   : Semigroup axioms
% Version  : [MOW76] axioms.
% English  :

% Refs     : [MOW76] McCharen et al. (1976), Problems and Experiments for a
%          : [Ver93] Veroff (1993), Email to G. Sutcliffe
% Source   : [MOW76]
% Names    :

% Status   : Satisfiable
% Syntax   : Number of clauses     :    4 (   1 unt;   0 nHn;   3 RR)
%            Number of literals    :   12 (   1 equ;   8 neg)
%            Maximal clause size   :    4 (   3 avg)
%            Maximal term depth    :    2 (   1 avg)
%            Number of predicates  :    2 (   1 usr;   0 prp; 2-3 aty)
%            Number of functors    :    1 (   1 usr;   0 con; 2-2 aty)
%            Number of variables   :   18 (   0 sgn)
% SPC      : 

% Comments : [Ver93] pointed out that the traditional labelling of the
%            closure and well_definedness axioms was wrong. The correct
%            labelling indicates that product is a total function.
%          : I cut down the [MOW76] group axioms for this.
%--------------------------------------------------------------------------
%----This axiom is called closure or totality in some axiomatisations
cnf(total_function1,axiom,
    product(X,Y,multiply(X,Y)) ).

%----This axiom is called well_definedness in some axiomatisations
cnf(total_function2,axiom,
    ( ~ product(X,Y,Z)
    | ~ product(X,Y,W)
    | Z = W ) ).

cnf(associativity1,axiom,
    ( ~ product(X,Y,U)
    | ~ product(Y,Z,V)
    | ~ product(U,Z,W)
    | product(X,V,W) ) ).

cnf(associativity2,axiom,
    ( ~ product(X,Y,U)
    | ~ product(Y,Z,V)
    | ~ product(X,V,W)
    | product(U,Z,W) ) ).

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