Forever Undecided
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- $14.99
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- $14.99
Publisher Description
Forever Undecided is the most challenging yet of Raymond Smullyan’s puzzle collections. It is, at the same time, an introduction—ingenious, instructive, entertaining—to Gödel’s famous theorems.
With all the wit and charm that have delighted readers of his previous books, Smullyan transports us once again to that magical island where knights always tell the truth and knaves always lie. Here we meet a new and amazing array of characters, visitors to the island, seeking to determine the natives’ identities. Among them: the census-taker McGregor; a philosophical-logician in search of his flighty bird-wife, Oona; and a regiment of Reasoners (timid ones, normal ones, conceited, modest, and peculiar ones) armed with the rules of propositional logic (if X is true, then so is Y). By following the Reasoners through brain-tingling exercises and adventures—including journeys into the “other possible worlds” of Kripke semantics—even the most illogical of us come to understand Gödel’s two great theorems on incompleteness and undecidability, some of their philosophical and mathematical implications, and why we, like Gödel himself, must remain Forever Undecided!
PUBLISHERS WEEKLY
In these mathematical and logic puzzles, truth-telling knights battle lying knaves; a philosopher-logician named George falls in love with Oona, flighty bird-girl of the South Pacific; Inspector Craig and timid, conceited or modest reasoners match wits. Using such fictional enticements, the author of What Is the Name of This Book? and To Mock a Mockingbird steers us through the logical thickets of Kurt Godel's famous Incompleteness Theorem, which holds that mathematical systems can never prove their own consistency. Readers who make it halfway through this book will learn more symbolic logic than a college freshman stuffed with "new math.'' In the second half, the deeper waters of modal logic are navigated. This field, which dates back to Aristotle, impinges on current debates in computer science and artificial intelligence. Smullyan's gift is to make complex ideas both accessible and enjoyable to the persevering reader.
