'Put pictures under this picture.
Returns string, baseline arguments for stringPict.
Baseline is baseline of top picture
Examples
>>> from sympy.printing.pretty.stringpict import stringPict
>>> print(stringPict("x+3").below(
...       stringPict.LINE, \'3\')[0]) #doctest: +NORMALIZE_WHITESPACE
x+3
3'

def below(self, *args):

    (s, baseline) = stringPict.stack(self, *args)
    return (s, self.baseline)
