This is probably old news to many people, but I just noticed that this page (scroll down a bit) http://www-cs-faculty.stanford.edu/~knuth/taocp.html has quite a bit in the way of "Knuth Vol 4" preview material on it. There's easily several hundred pages of stuff there embedded in downloadable .ps.gz files. Here's a puzzle from it [rated 25 on the Knuth scale] What is the 7.2.1.2.26: What is the unique alphametic solution to NIIHAU \pm KAUAI \pm OAHU \pm MOLOKAI \pm LANAI \pm MAUI \pm HAWAII = 0? (\pm : "plus or minus") * * * * * Knuth writes: The material will first appear in beta-test form as fascicles of approximately 128 pages each, issued approximately twice per year. These fascicles will represent my best attempt to write a comprehensive account, but computer science has grown to the point where I cannot hope to be an authority on all the material covered in these books. Therefore I'll need feedback from readers in order to prepare the official volumes later. The publishers have pledged to make the fascicles available in an inexpensive form, essentially at cost. (Of course, the paper and binding will probably be designed to self-destruct in a few years, so that you will have to buy the real book after it is debugged:-) If all goes as planned, Volumes 4A, 4B, and 4C will be ready in the year 2007. Some "pre-fascicles" are now available for alpha-testing: Pre-fascicle 2a (Generating all n-tuples); Pre-fascicle 2b (Generating all permutations); Pre-Fascicle 3a (Generating all combinations). Pre-Fascicle 3b (Generating all partitions). I've put them online primarily so that experts in the field can check the contents before I inflict them on a wider audience. But if you want to help debug them, please go right ahead. Thane Plambeck 650 321 4884 office 650 323 4928 fax http://www.plambeck.org