+1 on the lambda calculus stuff. Here's a related talk about deriving the Y combinator in Ruby by Jim Weirich: http://www.youtube.com/watch?v=FITJMJjASUs http:

+1 on the lambda calculus stuff. Here's a related talk about deriving the Y combinator in Ruby by Jim Weirich: http://www.youtube.com/watch?v=FITJMJjASUs http://www.youtube.com/watch?v=FITJMJjASUs (skip to about 28:00 if you're impatient) There are additional versions of this same presentation circulating with the code in Javascript and (I believe) Clojure. Full disclosure: Jim is a co-worker of mine.