“…r ′ ,p ′ and A r ′′ r ′ (x, t) = A r ′′ r ′ are diagonal 9 and independent of (x, t), and thus obviously independent of ⟨q r ′ ,p ′ ⟩ β(x,t) and ⟨q J r ′ ⟩ β(x,t) , respectively. This simplifies the treatment considerably compared to the general situation, see, e.g., [3].…”