\[B_{s}(\xi)=-A_{s}^{\prime}(\xi)+\frac{1}{|\xi|^{1/2}}\int_{\xi}^{0}\left(\psi(%
v)A_{s}(v)-\left(\nu+\tfrac{1}{2}\right)A_{s}^{\prime}(v)\right)\frac{\,%
\mathrm{d}v}{|v|^{1/2}},\]