Entries written in September 2009
- 09.27 Open problem 70 posted in Unsolved problems
- 09.17 Ex 10.3.6 (c) posted in Questions
- 09.17 page 317 (first edition), page 321 (second printing) posted in Punctuation
- 09.11 Exercise 1.4.6a posted in Errata
- 09.02 Hint to ex 4.2.5 (b) posted in Errata, Hints
- 09.02 Hint to ex 4.1.15 posted in Solutions
