Abandoned after two chapters, that is after chapter 1: when a book that starts at chapter 0 it acts as a warning sign to me and I was right to be wary. This is a book by a mathematician for mathematicians and it might very well be excellent for its intended audience. I am not a mathematician, however, and I found it completely useless for my needs. Hence, I haven't rated the book because it may not actually be bad, just inappropriate for me.