# Spring 2014 MATH 245A 001 LEC

Section | Days/Time | Location | Instructor | CCN |
---|---|---|---|---|

001 LEC | TuTh 1230-2P | 81 EVANS | BERGMAN, G M | 54426 |

Units/Credit | Final Exam Group | Enrollment |
---|---|---|

4 | NONE | Limit:30 Enrolled:10 Waitlist:0 Avail Seats:20 [on 05/28/14] |

**Prerequisite**: The equivalent of one of Math H113 or 114 or
250A, or consent of the instructor.

**Syllabus:**
The theme of Math 245A, as I teach it, is
*universal constructions*.
We begin with a well known case,
the construction of *free groups*.
We will develop this in three quite different ways, and show why they
come to the same thing.
We then examine a smorgasbord of other important universal
constructions, noting similarities, differences,
and general patterns.

After that, we settle down to developing the tools needed to study
the subject in a unified
way: Ordered sets and the axiom of choice, closure
operators, category theory, and the general concept of a variety of
algebras.
(We in fact treat most of these, not merely as means to
this goal, but as interesting landscapes worth lingering over.)
We find that the free group construction is a particular example
of an *adjoint functor* (it is left adjoint to the underlying-set
functor on groups), and eventually develop a magnificent result of
Peter Freyd, characterizing those functors between varieties of
algebras that have left adjoints, and we determine, in several
cases, *all* such examples.

**Office:** 865 Evans Hall

**Office Hours:** Tues. 2-3, Weds., 12-1, Fri. 3-4

**Required Text:** *General Theory of Algebraic Structures,* 469 pages of course notes, readable online at http://math.berkeley.edu/~gbergman/GenAlg.pdf , available softbound at $48.50 from Copy Central, 2576 Bancroft Way.

**Recommended Reading:** None (though some other texts useful for various purposes are discussed on pp.12-13 of the notes).

**Homework and grading:** The text contains more interesting exercises than anyone could do. I will ask you to think briefly about each exercise, and select a few to hand in each week; more details at the first class meeting. Grades will be based mainly on this homework. Students wishing a reduced homework-load can enroll S/U.

**Comments:**
My philosophy is that it does not make sense to spend the classroom
time using the instructor and students as an animated copying
machine.
Rather, the material that is typically delivered in a lecture should
be put in duplicated notes which the students study, and class time
should be devoted to the more human activities of discussing and
clarifying the material, introducing some topics by the Socratic
method, etc..
Such notes for Math 245, begun in Fall 1971 and
reworked each time I have taught the course, have developed into the
text we will use.

There are difficulties with this way of teaching if a textbook leaves out motivation, examples, etc., that might be included in a lecture; but I have made it a point to include these in the notes. Another problem is that doing the reading before class runs counter to the habits many students have acquired. To get around this, I require each student to submit, on each class day, a question about the day's reading, if possible by e-mail at least an hour before class, so that I can prepare to address some of these questions in class.