https://twitter.com/#!/mr_konn/status/108006895209553920

gistfile1.hs

data Gender = Male | Female deriving (Show, Eq)
data Race = Martian | Venusian deriving (Show, Eq)

answer (Venusian, Male)       = id
answer (Martian, Female)      = id
answer (Venusian, Female)     = not
answer (Martian, Male)        = not

race x = (x==).fst
gender x = (x==).snd

and' x y = \p -> x p && y p
or' x y = \p -> x p || y p
not' x = \p -> not $ x p

pattern = [(Venusian, Male)
          ,(Martian, Female)
          ,(Venusian, Female)
          ,(Martian, Male)]

p = race Venusian

main = foldr (>>) (head res) (tail res) where
    res = map (\x -> print (x, answer x $ p x)) pattern