sucks. Just really sucks. Many a painful hour has been spent on this flaming pile of garbage. Maybe the book was just written for people vastly more intelligent than I, but I found it very challenging to understand. You MUST be very very very good at math to understand this completely. Would not recommend for those who are looking for a gentle introduction. The ratio of words to math is like 1/2. Literally incomprehensible unless you're some kind of wizard. Oh, yeah, and also there's like a bunch of mistakes in the book and solutions manual. So have fun wasting an entire day trying to figure out why you messed up a problem, when it was actually just a mistake in the book :))