I really enjoy learning new things in my free time. Lately I’ve been studying this book on Static Program Analysis. The book is very good, but some of the formulas are quite dense so I like to try writing them out in code. The chapter I’m currently reading (chapter 9) has a section on finding possibly-uninitialized variables using bipartite graphs. I’ve found it to be quite enjoyable, so in this post I would like to describe, in my own words, how to do it. We’ll start by analyzing some code from a toy programming language the book uses called “TIP”, and then we’ll use the techniques we developed to analyze some Ruby code.