http://www.colorless-sight.jp/wiki/?ProjectEular%2FProblem2
[[ProjectEular]] -- Problem 2 module Main (main) where import qualified Common as C (fibs) main :: IO () main = print $ problem2 problem2 :: (Integral a) => a problem2 = sum [ x | x <- takeWhile (< 4000000) C.fibs, even x ]