convert/Ei_related converts, when possible, special functions into Ei related functions. The Ei related functions are

FunctionAdvisor( Ei_related );

The 7 functions in the "Ei_related" class are:

$\left[\mathrm{Chi}\,\mathrm{Ci}\,\mathrm{Ei}\,\mathrm{Li}\,\mathrm{Shi}\,\mathrm{Si}\,\mathrm{Ssi}\right]$

$\mathrm{KummerU}\left(1\,1\,x\right)-\mathrm{WhittakerW}\left(-1\,-\frac{1}{2}\,-x^2\right)\exp \left(\frac{1}{2}{x}^2\right)$

$\mathrm{KummerU}\left(1\,1\,x\right)-\mathrm{WhittakerW}\left(\mathrm{-1}\,-\frac{1}{2}\,-x^2\right){\ⅇ}^{\frac{x^2}{2}}$

$\mathrm{convert}\left(\,\mathrm{Ei\_related}\right)$

${\mathrm{Ei}}_1\left(x\right){\ⅇ}^x-{\mathrm{Ei}}_2\left(-x^2\right)$