'Least common multiple of monomials.'

def lcm(self, other):

    if isinstance(other, Monomial):
        exponents = other.exponents
    elif isinstance(other, (tuple, Tuple)):
        exponents = other
    else:
        raise TypeError(('an    instance    of    Monomial    class    expected,    got    %s' % other))
    return self.rebuild(monomial_lcm(self.exponents, exponents))
