The following items are now available by ftp from ftp.cwru.edu. They are in the math/wells directory. sketch.dvi is the dvi file of a preliminary version of a report on sketches that I was inspired to write because of the upcoming meeting on Universal Algebra and Category Theory. This is a brief outline of the major ideas of sketch theory with an extensive bibliography. sketch.bib is the BibTeX input file for sketch.dvi. It contains quite a few papers not actually mentioned in the report. They all involve category theory but they don't all involve sketches. For those who are not familiar with BibTeX: This is a program that takes a paper written in TeX and a bibliography file in BibTeX input form (such files always have names that end in .bib) and produces a bibliography for the paper based on citations in the paper. Various BibTeX style files (they end in .bst) are available to produce different styles. BibTeX input form is very easy to understand. Here are some of my favorite examples: @ARTICLE{powerwells, author = "Power, A.J. and Charles Wells", title = "A Formalism for the Specification of Essentially Algebraic Structures in 2-Categories", journal = "Mathematical Structures in Computer Science", Volume = "2", year = "1992", pages = "1--28", } @BOOK{ctcs, author = "Barr, Michael and Charles Wells", title = "Category Theory for Computing Science", publisher = "Prentice-Hall International", year = "1990", series = "Prentice-Hall International Series in Computer Science", address = "New York", note = "The document \cite{ctcsup} contains corrections and additions to the book.", } In a paper writtei in TeX you would refer to the first one by writing "\cite{powerwells}" and the reference would come out as [Power and Wells, 1992] or [PW1992] or [1992] depending on the style file used. (You can make your own style file, too, if you understand reverse Polish.) My point in mentioning this is that a BibTeX input file (they always end in .bib) can be _very__useful_ even if you have no intention of ever using BibTeX, or TeX for that matter. (Or a computer, for that matter.) Charles Wells -- Charles Wells Department of Mathematics Case Western Reserve University +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++