Kinds missing from types in ghci

{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE PolyKinds #-}

data family F (a:: k)

foo :: F (m :: [()]) -> a
foo = undefined
bar :: F (m :: [[()]]) -> a
bar = undefined

according to GHCi, both foo and bar have type F m -> a but [foo, bar] fails