Hi, For reference, my compiler does cheat :-) (emacs@REDACTED)9> iter:timeing(100000). recursion: 1 true revrecursion: 15998 true mapfun: 15000 true listcompr: 1 true In any case, I think each function should be called in a separate fresh process, as Björn also pointed out. Otherwise the results might not be conclusive. Regards, Vlad