subjects. He gives two reasons for his rejection: the AI program is supposed to emulate creativity, while an average of human responses will delete any original insight by any of the single subjects; and the architecture of the program should be more important that its mere functional description. In the main article, the architecture of Tabletop is described: it is strongly inspired by that of Copycat and consists of a Slipnet, a Workspace, and a Corerack. Chapter 10: Letter Spirit This last chapter is about a more ambitious project that Hofstadter started with student Gary McGraw. The microdomain used is that of grid fonts: typographic alphabets constructed using a rigid system of small rigid components. The goal is to construct a program that, given only a few or just one letter from the grid font, can generate the whole alphabet in the same style. The difficulty lies in the ambiguity and undefinability of style. The projected program would have a structure very similar to that of Jumble, Numble, Copycat, and Tabletop. Epilogue In the concluding part of the book, Hofstadter analyses some AI projects with a critical eye. He finds that today's AI is missing the gist of human creativity and is making exaggerated claims. The project under scrutiny are the following. AARON, a computer artist that can draw images of people in outdoor settings in a distinctive style reminiscent of that of a human artist; criticism: the program doesn't have any understanding of the objects it draws, it just uses some graphical algorithms with some randomness thrown in to generate different scenes at every run and to give the style a more natural feel. Racter, a computer author that wrote a book entitled The Policeman's Beard Is Half Constructed. Although some of the prose generated by the program is quite impressive, due in part to the Eliza effect, the computer does not have any notion of plot or of the meaning of the words it uses. Furthermore, the book is made up of selected texts from thousands produced by the computer over several years. AM, a computer mathematician that generates new mathematical concepts. It managed to produce by itself the notion of prime number and the Goldbach conjecture. As with Racter, the question is how much the programmer filtered the output of the program, keeping only the occasional interesting output. Also, mathematics being a very specialized domain, it is