Exercise 2.24 - tree fundamentals
Exercise 2.25: tree traversal with car/cdr is ANNOYING
Exercise 2.26 - low-level list manipulation is STILL SLIGHTLY CONFUSING
Exercise 2.27: deep-reverse all nested elements in a list. the first non-trivial exercise in a while... (I'm gonna regret typing that, I just know it...)
Exercise 2.28 - passes all tests from the book, so that's it for me...
added comment
Exercise 2.29 - balancing a binary mobile. CS 1, anybody?
Disabled test code
Exercises 2.30-31: basic tree traversal and rebuilding (map + recursion will reduce bookkeeping)
dead ends before catching my typo
Exercise 2.32 - much easier once (1) you work it out on paper and (2) don't have any typos