Here is the PDF file for the notes from which Berkeley's Math 245A, "General Theory of Algebraic Structures", is being taught in Spring 2014. You can access it here, and/or buy a softcover printed copy for $48.50 at Copy Central, 2576 Bancroft Way, Berkeley.
(The above is the first TeXed version of those notes. I still have some printed copies of the previous version, prepared using the old word-processing system troff. For Postscript and PDF files of that version, and information on how to buy printed copies if you wish, click here. But students in the course should use the latest version.)
Here is a list of errata and addenda to the current notes, which will be added to as we go through the course. If you have further corrections or comments, you can e-mail me: .
I will maintain a list of answers to some questions submitted by students over the course of the semester. Here is a similar list from Spring 2008 and Fall 2011 (referring to the not-very-different preceding version of the text). I will fuse these two files after the end of the semester.