Practical Foundations of Mathematics Paul Taylor Department of Computer Science Queen Mary and Westfield College London E1 4NS http://www.dcs.qmw.ac.uk/~pt/book/ Cambridge Studies in Advanced Mathematics #59 (the series in which "Stone Spaces" by Johnstone and "Introduction to Higher Order Categorical Logic" by Lambek and Scott appeared.) ISBN: 0-521-63107-6 xii+576 pages List price: £50 or $80 I understand that the text and cover have now been printed, and are due to be bound on Monday 22 March in Cambridge, so I expect to see my own copy by the end of next week; orders should be dispatched after the Easter holiday. PLEASE SEE BELOW FOR THE BEST WAY TO ORDER YOUR COPY. The (not very informative) names of the chapters are: I First Order Reasoning VI Structural Recursion II Types and Induction VII Adjunctions III Posets and Lattices VIII Algebra with Dependent Types IV Cartesian Closed Categories IX The Quantifiers V Limits and Colimits The back cover "blurb" reads: Practical Foundations collects the methods of construction of the objects of twentieth century mathematics. Although it is mainly concerned with a framework essentially equivalent to intuitionistic ZF, the book looks forward to more subtle bases in categorical type theory and the machine representation of mathematics. Each idea is illustrated by wide-ranging examples, and followed critically along its natural path, transcending disciplinary boundaries between universal algebra, type theory, category theory, set theory, sheaf theory, topology and programming. The first three chapters will be essential reading for the design of courses in discrete mathematics and reasoning, especially for the ``box method'' of proof taught successfully to first year informatics students. Chapters IV, V and VII are an introduction to categorical logic. Between the formal languages translations are provided which are fluent, showing how to write vernacular proofs which are sound in formal logics. Chapter VI is a new approach to term algebras, induction and recursion, which have hitherto only been treated either naively or with set theory. The last two chapters prove in detail the equivalence of types and categories, in particular between generalised algebraic theories and categories with display maps. Students and teachers of computing, mathematics and philosophy will find this book both readable and of lasting value as a reference work. The web page currently just gives just the list of contents (down to the names of subsections), but when I have time to work on it I intend use it to publish many of the specific comments that people have made about the text (if those people are willing), and provide an interface for making further comments, and, of course, corrections. CUP has indicated that they have no objection to my publishing the entire text on the web in any form short of a printable DVI or PS file; when I have found a translator that actually works on my text, I intend to make an HTML version, obviously without most of the mathematical formulae, to feed to the web crawlers. HOW BEST TO ORDER YOUR COPY This depends on whether you would like to make a large donation to (a) your bookstore's profits: just quote the ISBN to them; (b) CUP's profits: fill in their web order form (no discount, by policy, and you pay cost of postage); (c) the UK Inland Revenue: wait until April 6 before you do anything; (d) the author, who has committed career suicide by writing this book at all. The special deal that I have negotiated is this. CUP is ADAMANT that it is contrary to their policy to give discounts for direct orders, even though the Web is now clearly the best way of ordering research-level books. However, by personal arrangement with my editor and the marketing manager, if you email, fax or phone the marketing manager, Richard Knott, email: rknott@cup.cam.ac.uk tel: +44 1223 325 916 fax: +44 1223 315 052, with your address and credit card number, mentioning that you saw this message from me, you get the book at list price INCLUSIVE of overland postage (normally £2.50), and I get some commission. If you want airmail delivery, there is an extra £2.50 charge. If you are not sure whether you actually want to buy the book yet, but you think you might (or might be teaching a course based on it) please email Richard Knott and say so, as soon as possible. If I get evidence of respectable sales prospects then I might persuade them to pay me an advance on royalties THIS MONTH - in the tax year during which I was unemployed for five months - instead of having a lump sum in May 2000 taxed at 40%. Please, this is important if you think that academic authors deserve some reward for the labour and demoralisation of eight years writing a book. £50 is pretty good value for a research book of this size. A recently announced book on similar material, published by the Dutch company Elsevier (North-Holland) costs TWICE the price (for 1/3 more pages). CUP, being part of Cambridge University, has no shareholders and counts as a charity for tax purposes, and there is no VAT on books in Britain. Even so, other recent books of same size in the same series as mine retail at £65. I kept the price of mine down by doing the whole of the typographical work myself (of course), and by NOT claiming the £2350 that I could have got for providing lower quality camera-ready hard copy instead of PostScript. Paul PS Unfortunately, despite my best efforts, I was not able to negotiate a reduction in the Bank of England's interest rates, and therefore in the present absurdly high Sterling exchange rate. Sorry. I will try to do better next time. CUP's postal address is Cambridge University Press, The Edinburgh Building, Shaftesbury Road, Cambridge, CB2 2RU, UK.