∀ {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] (a : Aˣ) (x : ℝ) (ha : autoParam (0 ≤ ↑a) Units.cfcRpow._auto_1),
  ↑(a.cfcRpow x ha)⁻¹ = ↑a ^ (-x)