\begin{displaymath}
\Phi_i=A_i A_0+B_i\ln\left(\frac{x}{z \left(x+1\right)}\right)+C_i
       \ln\left(\frac{z}{x-z^2\left(x+1\right)}\right)
       \qquad,\qquad
       \zeta=\frac{1}{z^2-1}
\end{displaymath}


















