This book is the definitive and ultimate resource for any people engaged in mathematics. It is a sort of dictionary, where each entry is not a verbal string, but a mathematical function. For this reason it is beyond the scope of the volume explaining the various concepts involved, limiting itself to a mathematical definition for a function whatever. That does not mean, of course, did Explanations or pictures are missing. They are, but not on the fore. Usually, chapters end with Applications (ie in realm of physics) and Appropriate references. To stress, so if trivial, Is that the book does not cover the Entire realm of mathematics. It aims to collect only type of Mathematica object: function (or functional). Accordingly, no algebra, no topology, no geometry, and so on. To make one example: Dirac function is Analyzed as test-function and not as a mathematical tool for physics. Shortly: buy it!