So I said there wasn’t a proper newsletter this week, since I’m in Budapest prepping for a conference. But I still got a thing for y’all.

There’s a lot of interesting topics I wanted to cover for Logic for Programmers, but the book is dense enough as it is and many of these were too tangential or technical to fit in well. So I’ve been writing some supplements and uploading them here. I’ve got four so far:

1. How we compute the number of orderings of multiple concurrent processes

2. How first-order logic can quantify over “a set of functions”, what a “set of functions” looks like, and how functions can be defined in terms of sets (plus a bit on currying and type theory)

3. Barbara Liskov’s “history rule” in subtyping

4. Total and partial orders on sets.

Now I’m going to caveat that these were written off the cuff and haven’t gone through the obsessive editing of the book itself, so they may be rough and there might be errors in them. Still, it’s like 2-3000 words of math content, so hopefully covers not having a proper newsletter this time. Seeya next week!