Some recent interests

Only counting new interests, as opposed to things-I’ve-been-thinking-about-but-have-thought-about-before.

Riichi mahjong. I learned how to play riichi a few weeks ago because Brian, a former roommate, was into it, and so are several of my friends. After watching a tutorial on YouTube, I started playing on Mahjong Soul; I’ve now played 53 east matches and am ranked Adept 1.

At first I said I was only going to learn the rules and then stop playing, mostly because I was curious about how the game worked. But now I can talk some of the talk: I can discuss how to decide between toitoi and chiitoi, and how suji and kabe are used in defense, and the factors that go into declaring riichi versus staying in damaten.

Theory doesn’t quite translate to victory, though. Part of it is luck—in a single round among people of roughly similar skill, placing first is often a matter of getting good draws. That’s kinda cope, though; avoiding last place is more about skill than luck. I think I just haven’t practiced that much.

I have a similar relationship with go, where I’m also conversant but mediocre. I’m a 13 kyu on OGS, even though I know some joseki and can recognize some bad shape and can recite some proverbs, which is enough knowledge to make some of my friends surprised at how low my rating is. And the thing is, I know I can get better at go if I did a lot more tsumego, but somehow that idea’s not super appealing.

Linear type theory. While my interest in type theory dates back to 2021, the kind of type theory I read the most about was in the cluster of intuitionistic type theory. A few days ago I was invited as a guest to a demo day at the Recurse Center, where someone gave a presentation about doing sketchy type algebra. This spurred me to think about what subtracting or dividing types might mean, which led me to How to Take the Inverse of a Type, which answers this question in the context of linear type theory.

Linear type theory is based on linear logic, much like how intuitionistic type theory is based on intuitionistic logic. If you take classical logic, and disallow excluded middle, you get intuitionistic logic. Similarly, if you take intuitionistic logic, and disallow contraction and weakening, you get linear logic. There’s a programming interpretation of this: a value with a linear type is a resource used exactly once; it’s never duplicated or shared (no contraction), and never discarded (no weakening).

I haven’t gotten into linear type theory in the past, mostly because I haven’t found an exposition I liked. But the presentation in How to Take the Inverse of a Type feels pretty good to me. I think it’s because there aren’t !s and ?s everywhere.

US tort law. Most of my familiarity with US law has to do with immigration law. Unlike what the name might suggest, immigration law includes topics like nonimmigrant visa policy, which is particularly relevant to me, because I am in the US under nonimmigrant status. Immigration law falls under the broader umbrella of administrative law, and my vibe is that administrative law has a lot do with statutory interpretation. Much of US immigration law has to do with the INA, or the Immigration and Nationality Act of 1952, and its many amendments over the years.

This is in contrast to tort law, which has a lot more to do with judicial precedent. Whereas the study of immigration law involves a decent amount of reading the INA itself, studying tort law, apparently, involves a lot of reading past cases. Compare these two casebooks I found on H2O on immigration and torts; the latter is almost entirely case excerpts. I’ve been most amused by reading This Week in Torts, and the surrounding material it cites.

Ark Nova. Consider the top three games on BoardGameGeek. You have Brass: Birmingham, a gritty economic game set in industrial-revolution-era Britain that’s merciless in requiring its players to conduct a mechanical symphony, followed by Pandemic Legacy: Season 1, a difficult cooperative game about waging a tense battle against a worldwide epidemic while often being on the losing end, and Ark Nova, where you plan a zoo and collect cute animals.

While Ark Nova’s theming isn’t as intense or dark as the top two games, it’s more than comparable in replay value, tactical depth, and emergent complexity. Playing the game well requires a ruthless, calculating efficiency when it comes to taking actions. It’s a game that values short-term tactics and reacting to situations as they arise, over longer-term strategies and big combos. That’s probably my favorite part of the game, which is how fluid it feels when you’re playing.

I enjoy playing Ark Nova in-person, after my roommate Jason acquired a copy. I think I’ve played 8 games face-to-face. But I get more playtime online at Board Game Arena. My BGA stats say I’ve played 15 ranked games, 6 unranked games, and 11 solo games. If I sorted the things on this post by how much of my brain space they’ve been occupying these past few days, Ark Nova would easily top.