Hacking your program is no substitute for understanding your problem. Prolog is different, but not that different. Elegance is not optional. These are the themes that unify Richard O'Keefe's very personal statement on how Prolog programs should be written. The emphasis in The Craft of Prolog is on using Prolog effectively. It presents a loose collection of topics that build on and elaborate concepts learned in a first course. These may be read in any order following the first chapter, "Basic Topics in Prolog," which provides a basis for the rest of the material in the book.