  We show that all nontrivial CP-violating phases can be determined in terms of
three lepton flavor mixing angles and the ratio of $\Delta m^2_{\rm sun}$ to
$\Delta m^2_{\rm atm}$ in the minimal seesaw model in which the
Frampton-Glashow-Yanagida (FGY) ansatz is incorporated. This important point
allows us to make very specific predictions for the cosmological baryon number
asymmetry and CP violation in neutrino oscillations. A measurement of the
smallest neutrino mixing angle will sensitively test the FGY ansatz, in
particular in the case that three light neutrinos have a normal mass hierarchy.
