'Returns the lower bound of the ``Idx``.
Examples
>>> from sympy import Idx
>>> Idx(\'j\', 2).lower
0
>>> Idx(\'j\', 5).lower
0
>>> Idx(\'j\').lower is None
True'

@property
def lower(self):

    try:
        return self.args[1][0]
    except IndexError:
        return
