∀ {A : Type u_1} [inst : PartialOrder A] [inst_1 : Ring A] [inst_2 : StarRing A] [inst_3 : TopologicalSpace A]
  [inst_4 : StarOrderedRing A] [inst_5 : Algebra ℝ A] [inst_6 : ContinuousFunctionalCalculus ℝ A IsSelfAdjoint]
  [inst_7 : NonnegSpectrumClass ℝ A] [IsTopologicalRing A] [T2Space A] (a : A) (x : ℝ),
  IsUnit a → x ≠ 0 → autoParam (0 ≤ a) CFC.rpow_rpow_inv._auto_1 → (a ^ x) ^ x⁻¹ = a