def tau0_from_mass1_mass2(mass1, mass2, f_lower):
    r"""Returns :math:`\tau_0` from the component masses and given frequency.
    """
    mtotal = mass1 + mass2
    eta = eta_from_mass1_mass2(mass1, mass2)
    return tau0_from_mtotal_eta(mtotal, eta, f_lower)
def tau0_from_mass1_mass2 ( mass1 , mass2 , f_lower ) : mtotal = mass1 + mass2 eta = eta_from_mass1_mass2 ( mass1 , mass2 ) return tau0_from_mtotal_eta ( mtotal , eta , f_lower )
r"""Returns :math:`\tau_0` from the component masses and given frequency.