Data.Category.NaturalTransformation
type f :~> g
type Component f g z
data Nat
type Endo k
type Presheaves k
type Profunctors c d
data FunctorCompose c d e
type EndoFunctorCompose k
type Precompose f e
type Postcompose f c
data Wrap f h
data Apply c1 c2
data Tuple c1 c2