An Introduction to Formal Logic was first published by Cambridge University Press in November 2003.
However, a heavily corrected second printing came out in April 2009 (and we are now on the fifth printing). You should be using this much improved version. You can tell the original version from the corrected reprints by looking at the publication details halfway down the verso of the title page — or by seeing whether the last paragraph of the Preface thanks people for corrections to the first printing. (NB: A corrected reprint doesn’t count as a new edition so it doesn’t have a new ISBN: but the revised version will be what is supplied by bookshops, Amazon, etc.)
The headline news is that this is an initially very gentle-paced introduction to logic by trees, though it does get as far as a completeness proof for quantificational logic (included for enthusiasts). Until this academic year, it was the text book for the compulsory first-year logic course for Cambridge philosophers. Click on the thumbnail of its cover to go to the publisher’s page for the book. And from there you look at the table of contents and a short excerpt.
There are additional support materials available:
- A corrections page for the second (and later) printings. (There are still more small typos than I would like, though only a small handful could cause any problem.)
- The answers to nearly all the end-of-chapter exercises in the book.
- The Worksheets for my most recent Cambridge 1A course.
- Some lecture overheads, additional draft chapters and various handouts.
- The nextstep after IFL?
There are not only the inevitable typos but also a few quite horrible “thinkos” in the first printing. So, if you are still using that version of the book, please download
That gives a fairly complete list of the major outright typos in the first printing. But note, the list does not catalogue all the little improvements in the second printing where the text has been improved. So it is much the best just to ignore second-hand copies of the first version: buy (or get your library to buy) the significantly improved, and still pretty cheap, later revised version!