It is a modified version of the beautiful lecture notes of my late friend, Gilles Castel. Different features and macros are taken from several sources according to my preference and necessity. For ...

$\displaystyle \mathrm{Edition\ (e)} = \sum \limits _{n=0}^{\infty }{\frac {1}{n!}} = 1 + {\frac {1}{1}}+{\frac {1}{1\cdot 2}}+{\frac {1}{1\cdot 2\cdot 3}}+\cdots = 2 ...