This chapter contains more PROLOG and is useful in case you want to do more with PROLOG than just the limited amount covered in the book. It can save you from having to buy a PROLOG book. It was removed from the book on the grounds that many people may not want it and some instructors may want to use an entire PROLOG book anyway and then students end up paying twice, once for the pages in this book and again for some other PROLOG book. The chapter is available in HTML and also is a available as a zipped 53K postscript file. This material is copyright by me and CANNOT be used for ANY commercial purpose. Note that while this file was spell-checked it has not been grammar checked by any program or person and I don't know any English grammar, I only know what sounds right. Comments on grammar, typesetting and contents are welcome.