\[E\left(1/k^{\prime}\right)=(1/k^{\prime})\left(E\left(k^{\prime}\right)\mp%
\mathrm{i}E\left(k\right)-k^{2}K\left(k^{\prime}\right)\pm\mathrm{i}{k^{\prime%
}}^{2}K\left(k\right)\right),\]