T15243.hs:(11,2)-(16,7): Splicing declarations
    [d| type family F (a :: k) :: k where
          F 'Unit = 'Unit
          F '(,) = '(,)
          F '[] = '[]
          F '(:) = '(:) |]
  ======>
    type family F (a :: k) :: k where
      F 'Unit = 'Unit
      F '(,) = '(,)
      F '[] = '[]
      F '(:) = '(:)