Exercise 4.25: didn't do it, but added another nltk api function to my notes
Examples 4.2 and 4.3 from Chapter 4 EXTRAS - umodified
test code and my notes
Chapter 4 Extras 4.3: Chinese and XML
Chapter 4 Extras Section 4.5.1: Sorting Algorithms
they mentioned a new nltk api function in passing in Chapter 4 Extras section 4.5
Chapter 4 Extras - Exercise (the one and only)
Example 4.4 from Chatper 4 Extras Section 4.7.2: Hill-Climbing Search - unmodified
test code and my notes - this example builds on code_anneal (Example 3.10)