Singletons/T376.hs:(0,0)-(0,0): Splicing declarations
    singletons
      [d| f :: (() -> ()) -> (() -> ())
          f g = g :: () -> () |]
  ======>
    f :: (() -> ()) -> () -> ()
    f g = g :: () -> ()
    type FSym2 (a0123456789876543210 :: (~>) () ()) (a0123456789876543210 :: ()) =
        F a0123456789876543210 a0123456789876543210
    instance SuppressUnusedWarnings (FSym1 a0123456789876543210) where
      suppressUnusedWarnings = snd (((,) FSym1KindInference) ())
    data FSym1 (a0123456789876543210 :: (~>) () ()) :: (~>) () ()
      where
        FSym1KindInference :: forall a0123456789876543210
                                     a0123456789876543210
                                     arg. SameKind (Apply (FSym1 a0123456789876543210) arg) (FSym2 a0123456789876543210 arg) =>
                              FSym1 a0123456789876543210 a0123456789876543210
    type instance Apply (FSym1 a0123456789876543210) a0123456789876543210 = F a0123456789876543210 a0123456789876543210
    instance SuppressUnusedWarnings FSym0 where
      suppressUnusedWarnings = snd (((,) FSym0KindInference) ())
    data FSym0 :: (~>) ((~>) () ()) ((~>) () ())
      where
        FSym0KindInference :: forall a0123456789876543210
                                     arg. SameKind (Apply FSym0 arg) (FSym1 arg) =>
                              FSym0 a0123456789876543210
    type instance Apply FSym0 a0123456789876543210 = FSym1 a0123456789876543210
    type family F (a :: (~>) () ()) (a :: ()) :: () where
      F g a_0123456789876543210 = Apply (g :: (~>) () ()) a_0123456789876543210
    sF ::
      forall (t :: (~>) () ()) (t :: ()).
      Sing t -> Sing t -> Sing (Apply (Apply FSym0 t) t :: ())
    sF
      (sG :: Sing g)
      (sA_0123456789876543210 :: Sing a_0123456789876543210)
      = (applySing (sG :: Sing (g :: (~>) () ()))) sA_0123456789876543210
    instance SingI (FSym0 :: (~>) ((~>) () ()) ((~>) () ())) where
      sing = (singFun2 @FSym0) sF
    instance SingI d =>
             SingI (FSym1 (d :: (~>) () ()) :: (~>) () ()) where
      sing = (singFun1 @(FSym1 (d :: (~>) () ()))) (sF (sing @d))