'Multiply two polynomials ``f`` and ``g``.
Examples
>>> from sympy import Poly
>>> from sympy.abc import x
>>> Poly(x**2 + 1, x).mul(Poly(x - 2, x))
Poly(x**3 - 2*x**2 + x - 2, x, domain=\'ZZ\')
>>> Poly(x**2 + 1, x)*Poly(x - 2, x)
Poly(x**3 - 2*x**2 + x - 2, x, domain=\'ZZ\')'

def mul(f, g):

    g = sympify(g)
    if (not g.is_Poly):
        return f.mul_ground(g)
    (_, per, F, G) = f._unify(g)
    if hasattr(f.rep, 'mul'):
        result = F.mul(G)
    else:
        raise OperationNotSupported(f, 'mul')
    return per(result)
