∀ {E : Type u_1} [inst : NormedAddCommGroup E] [NormedSpace ℝ E] {𝕜 : Type u_3} {G : Type u_4}
  [inst_2 : NontriviallyNormedField 𝕜] [IsRCLikeNormedField 𝕜] [inst_4 : NormedSpace 𝕜 E]
  [inst_5 : NormedAddCommGroup G] [inst_6 : NormedSpace 𝕜 G] {f : E → G},
  Differentiable 𝕜 f → (∀ (x : E), fderiv 𝕜 f x = 0) → IsLocallyConstant f