Singletons/BoxUnBox.hs:(0,0)-(0,0): Splicing declarations
    singletons
      [d| unBox :: Box a -> a
          unBox (FBox a) = a
          
          data Box a = FBox a |]
  ======>
    data Box a = FBox a
    unBox :: Box a -> a
    unBox (FBox a) = a
    type FBoxSym1 (t0123456789876543210 :: a0123456789876543210) =
        FBox t0123456789876543210
    instance SuppressUnusedWarnings FBoxSym0 where
      suppressUnusedWarnings = snd (((,) FBoxSym0KindInference) ())
    data FBoxSym0 :: forall a0123456789876543210.
                     (~>) a0123456789876543210 (Box a0123456789876543210)
      where
        FBoxSym0KindInference :: forall t0123456789876543210
                                        arg. SameKind (Apply FBoxSym0 arg) (FBoxSym1 arg) =>
                                 FBoxSym0 t0123456789876543210
    type instance Apply FBoxSym0 t0123456789876543210 = FBox t0123456789876543210
    type UnBoxSym1 (a0123456789876543210 :: Box a0123456789876543210) =
        UnBox a0123456789876543210
    instance SuppressUnusedWarnings UnBoxSym0 where
      suppressUnusedWarnings = snd (((,) UnBoxSym0KindInference) ())
    data UnBoxSym0 :: forall a0123456789876543210.
                      (~>) (Box a0123456789876543210) a0123456789876543210
      where
        UnBoxSym0KindInference :: forall a0123456789876543210
                                         arg. SameKind (Apply UnBoxSym0 arg) (UnBoxSym1 arg) =>
                                  UnBoxSym0 a0123456789876543210
    type instance Apply UnBoxSym0 a0123456789876543210 = UnBox a0123456789876543210
    type family UnBox (a :: Box a) :: a where
      UnBox (FBox a) = a
    sUnBox ::
      forall a (t :: Box a). Sing t -> Sing (Apply UnBoxSym0 t :: a)
    sUnBox (SFBox (sA :: Sing a)) = sA
    instance SingI (UnBoxSym0 :: (~>) (Box a) a) where
      sing = (singFun1 @UnBoxSym0) sUnBox
    data instance Sing :: Box a -> GHC.Types.Type
      where SFBox :: forall a (n :: a). (Sing (n :: a)) -> Sing (FBox n)
    type SBox = (Sing :: Box a -> GHC.Types.Type)
    instance SingKind a => SingKind (Box a) where
      type Demote (Box a) = Box (Demote a)
      fromSing (SFBox b) = FBox (fromSing b)
      toSing (FBox (b :: Demote a))
        = case toSing b :: SomeSing a of {
            SomeSing c -> SomeSing (SFBox c) }
    instance SingI n => SingI (FBox (n :: a)) where
      sing = SFBox sing
    instance SingI (FBoxSym0 :: (~>) a (Box a)) where
      sing = (singFun1 @FBoxSym0) SFBox
    instance SingI (TyCon1 FBox :: (~>) a (Box a)) where
      sing = (singFun1 @(TyCon1 FBox)) SFBox