Exercise 2.40 - derp, can you pull a subroutine out of (prime-sum-pairs)? see my notes on section 2.2.3 for the straightforward implementation. Here, I added subroutine names, and things became sooooo much more comprehensible
Exercise 2.41: 'unique triples' with a given sum. SO much clearer when you use small, named, single-purpose procedures
tried doing the exercise with ugly ugly lambdas
Exercise 2.42 - all done except (safe?)
Exercise 2.42 completed, I think. Much easier with experience: incremental testing, and bite-sized subroutines
Exercise 2.43: Louis Reasoner sure knows how to slow down a program... analysis? meh