[Haskell-beginners] flip lookup in ghci

So what's this all about then? How come a has become ()? ghci> :t lookup lookup :: (Eq a) => a -> [(a, b)] -> Maybe b ghci> :t flip lookup flip lookup :: (Eq a) => [(a, b)] -> a -> Maybe b ghci> let lookupIn = (flip lookup :: (Eq a) => [(a, b)] -> a -> Maybe b ) ghci> :t lookupIn lookupIn :: [((), b)] -> () -> Maybe b