Read what leading experts say about the book:

This book is is undoubtedly going to be the definitive book on modal logic for years to come. (Moshe Y. Vardi)

It's a mine of information about modal logic and its semantics, bang up to date but with a strong sense of history. The text is well written for finding what you wanted, and if you browse it you are almost bound to learn some interesting facts that you never knew about. (Wilfrid Hodges)

This book will take you from ground level to one of the best vista points on modal logic today. The authors are expert guides: they know the land from first-hand research experience, but they are committed to taking all newcomers there as well.  (Johan van Benthem)

November 18, 2003 We just wrapped up correcting all known typos and errors for the second paperback printing.

Summer 2003 The paperback edition is available with a 12% discount at amazon.com. If you make an effort, the book can be found for as little as slightly more than USD 35.00.

August 22, 2002 As of today, the paperback version is available at a high quality book shop near you! We expect the hardback version to be available again later this year.

July 1, 2002 The hardback version of the book should be available again in August this year. The paperback version will be released in September 2002, and will cost UKP 29.95 (that is, half of what the hardback version costs!).

April 29, 2002 The hardback version of the book is sold out! We are currently arranging the publication of the paperback version, which should be available in a couple of months. In the meantime, if you are really desparate for a copy of the book, get in touch and we'll see what we can do.

June 28, 2001 As of today, the official publication date, we no longer provide free access to electronic versions of the main chapters of the book. Between November 1, 2000 and June 28, 2001 we have received over 4000 requests for chapters from the book. We'd like to thank everyone for their interest.

We continue to make some parts of the book available for free; click on the links to retrieve (compressed) PostScript files:

Title page and table of contents, i-vii Preface, viii-xix Chapter 1 (Basic Concepts, 1-49) Chapter 2 (Models, 50-123) Chapter 3 (Frames, 124-189) Chapter 4 (Completeness, 190-262) Chapter 5 (Algebras, 263-333) Chapter 6 (Computability and Complexity, 334-414) Chapter 7 (Extended Modal Logic, 415-487) Appendix A-C, (A Logical Toolkit, A Computational Toolkit, An Algebraic Toolkit), 488-518 Appendix D, (Guide to the Literature), 519-526 Bibliographic References, 527-546 Index, 547-552

The hard cover version is available now, for 110 Euros, 95 USD, or 60 UKP. Please consult these fine sites if you're considering buying the book: Amazon, Amazon (UK), CUP.

We're interested to find out what you think of the book; please visit the feedback page and leave a message.