Notes I’ve written from time to time.

I participate in the Cambridge Advanced Math Study Group meetup. Right now, there are three “streams”:

- Set Theory.
- General Relativity. No page for this yet.
- Lie Groups. No page for this yet

**Logic and Set Theory**

- Scott’s Model of the Lambda Calculus. These are based on some notes I wrote up in the early 1970s, for a seminar on an early version of Dana Scott’s model of the
*untyped*lambda calculus. These notes have nothing to say about Scott’s subsequent work on the typed lambda calculus, and the general notion of types. (Post) - Algorithmic Information Theory. I wrote these notes sometime in the early 90s, based mostly on Chaitin’s book
*Algorithmic Information Theory*. - Two items on recursion theory: Friedberg’s Enumeration without Duplication (post) and Simple Sets.

**Other Stuff**

- I participated in a meetup group that went through Leinster’s Basic Category Theory. I wrote up solutions to many exercises, plus supplementary material.