∀ {𝕜 : Type u_1} {E : Type u_2} [inst : SeminormedAddCommGroup E] [inst_1 : NontriviallyNormedField 𝕜]
  [inst_2 : NormedSpace 𝕜 E] (n : ℕ) (x : E →L[𝕜] E), Semiring.npow (n + 1) x = Semiring.npow n x * x