The exercises in Section 3.2, and some in Section 3.3, do not involve, or at least do not require, any code that needs to be verified by testing. (Section 3.2.1 does not even have any exercises.) The procedures are largely meant to be computed manually. Therefore there aren’t going to be any ‘exercise’ files, and they may only have a single post per sub-section. I will create solution files in order to demonstrate the code as needed, but most of the actual answers come from understanding the environment model diagrams, or in working out by hand what the result is. Running it through the interpreter is, as often as not, just a quick means of finding what the final expected result is. The exercises are really about figuring out how that result is produced. The solution posts will include my own diagrams in order to explain what happens at each step, rather than explanatory code snippets.