The purpose of this paper is to show that it is possible to translate almost every mathematical formula from LaTeX syntax to XML. The document you are reading contains a great number of formulas extracted from the TeX book, the LaTeX companion, the MathML recommendation, and translated into XML by Tralics; it is available in Pdf or HTML version. The HTML version was produced using a very simple style sheet; mathematics are left unchanged, and you need a MathML-aware browser, like Firefox, or adequate plugins, and a set of fonts for the symbols or operators. The Pdf version was obtained by use of xmltex (a package by D. Carlisle that makes TeX an XML interpreter), and a great number of modifications to the file mathml2.xmt (that interprets elements in the MathML namespace). All files needed to produce this document are part of the Tralics bundle (version 2.10 or more).