I originally planned for Chapter 9 of the book to be about additive combinatorics. However in the interests of completing the book before I die of old age, I am planning to make some cuts. It now looks like Chapter 9 (being a rather standalone topic in the context of the book) will hit the [...]

## Recent comments

Yongzhi: I think that the domain of the function g in Fact 21 should ...El Manolo: I can't figure out ex.12 b) and c) in the proposed way. Tha...R.: Is $\rho\neq 0$ required in 1(f)?R.: Typo: they introduced also introduced “tribes”Chin Ho Lee: they introduced also introduced “tribes” -> they also int...Mathias Niepert: This is not a correction but a question concerning the stabi...Ravi Boppana: In the hint to Exercise 21, should $(-\frac{1}{2} + \frac{\s...