> I also started to think about other things I could work on.

I'd like to suggest PG to dive into the theory.

From what PG was working on (on Bel), a great "continuation" would be to study category theory, type theory, especially dependent type theory.

I really wonder how is it like to debug (dynamically typed) lisp programs, with errors described as effectively encrypted given the current hype around statically typed system programming languages.