T7848.hs:10:9: error:
    • Couldn't match expected type ‘Char’ with actual type ‘a’
      ‘a’ is a rigid type variable bound by
        the type signature for:
          (&) :: forall a. a
        at T7848.hs:10:9-35
    • In the 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 #-}
                (&) = 'c'