The article seemed to be claiming that the Factor example was shorter than both the CL and Haskell ones. While the CL one is clearly the longest, the Haskell example seems at least as terse as the Factor example (`( 4 > )` in Haskell, vs `[ 4 > ]` in Factor - not sure if the parens in Haskell and the square brackets in Factor have the same amount of semantic weight though).

Oh, got it. I got confused, because the Haskell snippet is written in a point-free, not applicative style.

Personally, I attribute more "semantic weight" to the brackets in Factor. They have a much heavier definition of creating a lambda than Haskell's parenthesis, that only group operations.

(But I'm not sure if I prefer terseness to that level. Explicitness has value too.)

The Common Lisp example is a tiny bit disingenuous. Common Lisp programmers rarely write

  (function evenp)

but instead write the shorthand version

  #'evenp

Also, Common Lisp has a complement function which produces a new Boolean function with the negation of the result:

  (complement #'evenp)

vs the example:

  (lambda (n) (not (evenp n)))

Not much shorter by character count, but it is shorter by token count.

http://clhs.lisp.se/Body/f_comple.htm