\[\frac{{\partial}^{2}\mathcal{K}}{{\partial u}^{2}}+\frac{{\partial}^{2}%
\mathcal{K}}{{\partial v}^{2}}+\frac{{\partial}^{2}\mathcal{K}}{{\partial w}^{%
2}}+\frac{2\gamma-1}{u}\frac{\partial\mathcal{K}}{\partial u}+\frac{2\delta-1}%
{v}\frac{\partial\mathcal{K}}{\partial v}+\frac{2\epsilon-1}{w}\frac{\partial%
\mathcal{K}}{\partial w}=0.\]