Math Notes

Notes I’ve written from time to time.

Logic and Set Theory

  • I wrote some notes for a (now defunct) Set Theory meetup.
  • 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(Post)
  • Two items on recursion theory: Friedberg’s Enumeration without Duplication (post) and Simple Sets (post).
  • John Baez and I have been having a conversation about non-standard models of Peano arithmetic (PA). I have converted the story so far into pdf documents, formatted both for a small screen and a  medium-sized one. I will update these from time to time (but not that frequently).
  • We’ve also been having a conversation about first-order categorical logic.

Other Stuff