集合論のあれ

set.hs

data Fruit = Apple | Lemon | Banana

data Beverage = Coffee | Tea | Beer

data Temperature = Hot | Cool

-{
Food = { Food, Lemon, Curry }
Flavor = { Sweet, Sour, Spicy }
Temperature = { Hot, Cool }
-}

data Drink = Drink Beverage Temperature
  deriving (Show, Eq)