Unpublished, 2013. — 136 p.
The following is a set of class notes for the PMath 453/653 course I taught at the University of Waterloo in 2008. As mentioned on the front page, they are a work in progress, and - this being the \ rst edition" - they are replete with typos. A student should approach these notes with the same caution he or she would approach buzz saws; they can be very useful, but you should be thinking the whole time you have them in your hands.