Knuth's up-arrow notation

(defun knuth (x n)
  (if (= n 2)
      (return-from knuth (expt x x))
    (return-from knuth (expt x (knuth x (- n 1))))
    )
)


Yes, an implementation in 6 lines of Lisp. What is Knuth's up-arrow notation? Wikipedia that shit. Don't try this with anything greater than (knuth 3 3), or you will overflow. (knut 3 3) == 3^3^3. (knuth 3 4) == 3^3^3^3.

>>41
You're telling me you find it as readable as the versions in other languages on this page? Maybe you do, and all the more power to you; I have a really hard time believing it though.

Tell you what: make the absolute most readable version in Factor that you can. I have as much experience in Factor as I do in Lisp, Haskell, ML, and so forth, so I don't know the idioms of any of them. Convince me.