@staticmethod
def setup_command_line(parser):
    """Setup the command line options for Ordering principle formula

        Arguments:
        - `parser`: parser to load with options.
        """
    parser.add_argument('N', metavar='<N>', type=int, help='domain size')
    g = parser.add_mutually_exclusive_group()
    g.add_argument('--total', '-t', default=False, action='store_true',
        help='assume a total order')
    g.add_argument('--smart', '-s', default=False, action='store_true',
        help="encode 'x<y' and 'x>y' in a single variable (implies totality)")
    g.add_argument('--knuth2', action='store_const', dest='knuth', const=2,
        help='transitivity axioms: "(i<j)(j<k)->(i,k)" only for j>i,k')
    g.add_argument('--knuth3', action='store_const', dest='knuth', const=3,
        help='transitivity axioms: "(i<j)(j<k)->(i,k)" only for k>i,j')
    parser.add_argument('--plant', '-p', default=False, action='store_true',
        help='allow a minimum element')
