The first edition of this book was written in a burst of activity during the short period June 1996 through February 1997. The second edition was the result of intensive work during the second half of 1998 and the first half of 1999. The third edition includes material written, without haste, mostly in late 2002 and early 2003. The fourth edition was written, at a leisurely pace, during the first half of 2006. The book was designed by the author and was typeset by him with the TEX typesetting system developed by D. Knuth. The text and tables were done with Textures, a commercial TEX implementation for the Macintosh. The diagrams were done with Adobe illustrator, also on the Macintosh. Diagrams that required calculations were done either with Mathematica or Matlab, but even those were "polished" by Adobe Illustrator. The following points illustrate the amount of work that went into the book:

• The book (including the auxiliary material located in the book's Web site) contains about 523,000 words, consisting of about 3,081,000 characters (big, even by the standards of Marcel Proust). However, the size of the auxiliary material collected in the author's computer and on his shelves while working on the book is about 10 times bigger than the entire book. This material includes articles and source codes available on the Internet, as well as many pages of information collected from various sources.

• The text is typeset mainly in font cmr10, but about 30 other fonts were used.

• The...