Hi, On 12/12/12 17:24, Shea Levy wrote: > Huh? I didn't change the argument order, this is still a left fold. this just > short-circuits the eval of (x == a) when bs is true. "fold" is actually a right fold :-) -- Eelco Dolstra | LogicBlox, Inc. | http://nixos.org/~eelco/