T7848.hs:6:57: error:
    Occurs check: cannot construct the infinite type:
      t2 ~ t0 -> t -> t1 -> A -> A -> A -> A -> t2
    Relevant bindings include
      y :: forall t4. t4 -> t -> t1 -> A -> A -> A -> A -> t2
        (bound at T7848.hs:8:9)
      (&) :: t -> t1 -> A -> A -> A -> A -> t2 (bound at T7848.hs:11:9)
      z :: t1 (bound at T7848.hs:6:12)
      (&) :: t1 (bound at T7848.hs:6:8)
      (+) :: t (bound at T7848.hs:6:3)
      x :: t -> t1 -> A -> A -> A -> A -> t2 (bound at T7848.hs:6:1)
    In the expression: y
    In an equation for ‘x’:
        x (+) ((&)@z) ((:&&) a b) (c :&& d) (e `A` f) (A g h)
          = y
          where
              infixl 3 `y`
              y _ = (&)
              {-# INLINE (&) #-}
              {-# SPECIALIZE (&) :: a #-}
              (&) = x

T7848.hs:10:9: error:
    Couldn't match expected type ‘t -> t1 -> A -> A -> A -> A -> t2’
                with actual type ‘a’
      ‘a’ is a rigid type variable bound by
          the type signature for: (&) :: a at T7848.hs:10:9
    Relevant bindings include
      z :: t1 (bound at T7848.hs:6:12)
      (&) :: t1 (bound at T7848.hs:6:8)
      (+) :: t (bound at T7848.hs:6:3)
      x :: t -> t1 -> A -> A -> A -> A -> t2 (bound at T7848.hs:6:1)
    In the SPECIALISE pragma {-# SPECIALIZE (&) :: a #-}
    In an equation for ‘x’:
        x (+) ((&)@z) ((:&&) a b) (c :&& d) (e `A` f) (A g h)
          = y
          where
              infixl 3 `y`
              y _ = (&)
              {-# INLINE (&) #-}
              {-# SPECIALIZE (&) :: a #-}
              (&) = x