\[Y_{i\nu}\left(z\right)=\frac{i\operatorname{csch}\left(\nu\pi\right)}{\Gamma%
\left(1-i\nu\right)}(\tfrac{1}{2}z)^{-i\nu}-\frac{i\coth\left(\nu\pi\right)}{%
\Gamma\left(1+i\nu\right)}(\tfrac{1}{2}z)^{i\nu}+e^{|\nu\operatorname{ph}z|}o%
\left(1\right),\]