Your explanation is great! As a third option, if you'd like to have the relevant CS terminology, see Matt Might's derivation, also in JavaScript, at http://mat

Your explanation is great! As a third option, if you'd like to have the relevant CS terminology, see Matt Might's derivation, also in JavaScript, at http://matt.might.net/articles/implementation-of-recursive-fixed-point-y-combinator-in-javascript-for-memoization/ http://matt.might.net/articles/implementation-of-recursive-f....