Haskell function types

        inc n = n + 1
        inc :: Int -> Int

• Polymorphism:

        length :: [a] -> Int
        id     :: a -> a

• Anonymous functions:

        \n -> n + 1                 :: Int -> Int

        \x -> x                     :: a -> a
        \x -> 3                     :: a -> Int

• (The \ is supposed to remind you of a λ)