\[\begin{array}[]{ll}w^{\prime}_{\mbox{\tiny I}}(\tfrac{1}{2}\pi;a,q)=0,&a=a_{2n%
}\left(q\right),\\
w_{\mbox{\tiny I}}(\tfrac{1}{2}\pi;a,q)=0,&a=a_{2n+1}\left(q\right),\end{array}\]