${\mbox{$ \Delta  m^2_{\odot}$}}$ and $m_1^2$ do not exceed 1%. The same conclusion is valid for the corrections due to the terms $\sim {\mbox{$|U_{\mathrm{e} 1}|^2$}}$ as long as ${\mbox{$|U_{\mathrm{e} 1}|^2$}}\ltap 0.01$. For, e.g, ${\mbox{$ \Delta  m^2_{\odot}$}}\cong 2\times 10^{-4}~{\rm eV^2}$, ${\mbox{$|U_{\mathrm{e} 1}|^2$}}\cong 0.04$ and $m_1 \cong 0.02$ eV, the corrections due to the terms neglected in eq. (\[eqmassinvhierarchy02\]) can reach $\sim$(5-6)%. These terms, obviously, should be taken into account if they turn out to have the indicated (or larger) values and is measured with a comparable to the corrections, or somewhat larger, experimental error. In the latter case it will be necessary to use the exact formula for $\!\!$, eq. (\[eqmassinvhierarchy01\]), in order not to introduce avoidable sources of uncertainties. We are interested here only i) in analyzing the impact for the searches of CP-violation associated with the Majorana CP-violating phases of the uncertainty in $\!\!$, caused by the uncertainty in the evaluation of the relevant -decay nuclear matrix elements, and ii) in deriving limits on the nuclear matrix element uncertainty, which, if satisfied, could permit one to draw conclusions concerning the CP-violation of interest. Therefore in what follows we will use the approximate expression for $\!\!$, eq. (\[eqmassinvhierarchy02\]), but our results 