Acknowledgements
I'd like to thank all the readers of my previous books who have written to me with praise and sometimes with corrections. Of course, I appreciate the former very much, but I appreciate the latter as well; every correction a reader sends me makes the next printing or edition of the book that much better.

My primary technical reviewer, Donovan Rebbechi, found a number of ways to improve my code and my explanations thereof.

My copy editor, Vivian Clark, has the rare facility of correcting errors without interfering with my style in the process. Working with her, despite a few technical glitches, was a great improvement over my previous experience with this phase of book production.

Finally, I'd also like to thank my mother, Sali Heller Neff, and father, the late Leonard Heller. They had that rare but invaluable characteristic among parents: the courage and patience to let me do it my way.