ech (09/17/82)
#N:whuxlb:7200012:000:1405 whuxlb!ech Sep 17 02:27:00 1982 For the benefit of those who have not already discovered him, this is an endorsement of the works of Raymond Smullyan. If you were stimulated by the classic puzzle of the island of the truth-tellers and the liars, you have a treat in store. A year or so ago, on the recommendation of Martin Gardner in one of his last SA columns, I tried "What is the Name of This Book?" and enjoyed it thoroughly. I have just finished "The Lady or the Tiger?" (Knopf '82, $13.95) and he has definitely topped himself. In addition to a batch of new logic puzzles that will expand your skull (or twist it into a pretzel), the last half is a "novel" in which Inspector Craig of Scotland Yard and his associates track down self-referential systems and wind up with Godel's Incompleteness Theorem. I thought that Hofstadter did a good job with the material, but Smullyan has presents the cleanest exposition I have ever seen. Having done so, and having prepared the reader well, he dispatches the (analogous) halting problem in a 7 page windup chapter. Should be a prerequisite to a course on abstract machines. Get it! Aside: Smullyan also recently published "Alice in Puzzleland." There are some Alice puzzles in "What is the Name of this Book," and the latest book is excerpted in the October GAMES. I have left word that I expect to find it under the tree at Christmas if I can wait that long... =Ned Horvath=
wa125 (09/18/82)
I second the rave. Interested readers may also wish to check out the sequel, "This Book Needs No Title". (Really!)