Singletons/T367.hs:(0,0)-(0,0): Splicing declarations
    singletonsOnly
      [d| const' :: a -> b -> a
          const' x _ = x |]
  ======>
    type Const'Sym0 :: (~>) a ((~>) b a)
    data Const'Sym0 :: (~>) a ((~>) b a)
      where
        Const'Sym0KindInference :: SameKind (Apply Const'Sym0 arg) (Const'Sym1 arg) =>
                                   Const'Sym0 a0123456789876543210
    type instance Apply Const'Sym0 a0123456789876543210 = Const'Sym1 a0123456789876543210
    instance Data.Singletons.TH.SuppressUnusedWarnings.SuppressUnusedWarnings Const'Sym0 where
      Data.Singletons.TH.SuppressUnusedWarnings.suppressUnusedWarnings
        = snd ((,) Const'Sym0KindInference ())
    type Const'Sym1 :: a -> (~>) b a
    data Const'Sym1 (a0123456789876543210 :: a) :: (~>) b a
      where
        Const'Sym1KindInference :: SameKind (Apply (Const'Sym1 a0123456789876543210) arg) (Const'Sym2 a0123456789876543210 arg) =>
                                   Const'Sym1 a0123456789876543210 a0123456789876543210
    type instance Apply (Const'Sym1 a0123456789876543210) a0123456789876543210 = Const' a0123456789876543210 a0123456789876543210
    instance Data.Singletons.TH.SuppressUnusedWarnings.SuppressUnusedWarnings (Const'Sym1 a0123456789876543210) where
      Data.Singletons.TH.SuppressUnusedWarnings.suppressUnusedWarnings
        = snd ((,) Const'Sym1KindInference ())
    type Const'Sym2 :: a -> b -> a
    type family Const'Sym2 @a @b (a0123456789876543210 :: a) (a0123456789876543210 :: b) :: a where
      Const'Sym2 a0123456789876543210 a0123456789876543210 = Const' a0123456789876543210 a0123456789876543210
    type Const' :: a -> b -> a
    type family Const' @a @b (a :: a) (a :: b) :: a where
      Const' x _ = x
    sConst' ::
      (forall (t :: a) (t :: b).
       Sing t
       -> Sing t -> Sing (Apply (Apply Const'Sym0 t) t :: a) :: Type)
    sConst' (sX :: Sing x) _ = sX
    instance SingI (Const'Sym0 :: (~>) a ((~>) b a)) where
      sing = singFun2 @Const'Sym0 sConst'
    instance SingI d => SingI (Const'Sym1 (d :: a) :: (~>) b a) where
      sing = singFun1 @(Const'Sym1 (d :: a)) (sConst' (sing @d))
    instance SingI1 (Const'Sym1 :: a -> (~>) b a) where
      liftSing (s :: Sing (d :: a))
        = singFun1 @(Const'Sym1 (d :: a)) (sConst' s)