\[\begin{cases}1,&|\operatorname{ph}z|\leq\tfrac{1}{3}\pi,\\
\min\left(|\csc\left(\operatorname{ph}\zeta\right)|,\chi(n+\sigma)+1\right),&%
\tfrac{1}{3}\pi\leq|\operatorname{ph}z|\leq\tfrac{2}{3}\pi,\\
\frac{\sqrt{2\pi(n+\sigma)}}{|\cos\left(\operatorname{ph}\zeta\right)|^{n+%
\sigma}}+\chi(n+\sigma)+1,&\tfrac{2}{3}\pi\leq|\operatorname{ph}z|<\pi,\end{cases}\]