C. Lair has been sending messages to this mailing list with additions and corrections to my article, "Sketches : Outline with References", which I prepared for the joint meeting on universal algebra and category theory in Berkeley last July. It is available by ftp from ftp.cwru.edu in the math/wells directory (the file is sketch.dvi). The paper is a preliminary version, and in the next few weeks I intend to post a list of addenda and corrections to the paper in the same directory. They will include the papers Lair has mentioned, although I do not have most of them. (I expect to request some of them by interlibrary loan.) They will also include some other papers that I am embarrassed at having omitted because I DO own them. (These include papers by T. Fox and P. Johnstone and at least one by C. Lair.) Perhaps sometime next year I will have time for an extensive rewrite of the paper. It has expository shortcomings as well as bibliographical ones and I would hope to remedy some of them. Any suggestions concerning expositions and bibliography will be welcome. The paper begins, "This document is an outline of the theory of sketches with pointers to the literature. An extensive bibliography is given." It is NOT A HISTORY OF THE DEVELOPMENT OF SKETCHES. I did not claim that it was a history and I do not intend to make it one. The main emphasis is to describe papers in the literature that I think will be usable by those who want to learn about the subject, including people in universal algebra, theoretical computer science and other areas who would perhaps find expository papers and books more usable than the original sources. Even so, I want the bibliography to be inclusive and so appreciate being told of papers not mentioned. One specific comment: Any category theorist with some experience with sketches could derive the sketch for 2-categories. The paper by Power and me mentioned by Lair includes that sketch explicitly because our paper is written for theoretical computer scientists, who might not find it so easy to come up with the sketch. -- Charles Wells, Department of Mathematics, Case Western Reserve University 10900 Euclid Avenue, Cleveland OH 44106-7058, USA Phone 216 368 2880 or 216 774 1926 FAX 216 368 5163 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++