∀ {α : Type u_1} {m : MeasurableSpace α} {μ : MeasureTheory.Measure α} {E : Type u_2} [inst : NormedAddCommGroup E]
  [inst_1 : NormedSpace ℝ E] {𝕜 : Type u_3} [inst_2 : NontriviallyNormedField 𝕜] [inst_3 : NormedSpace 𝕜 E]
  [SMulCommClass ℝ 𝕜 E] (f : α → E) (r : 𝕜), (μ.withDensityᵥ fun x => r • f x) = r • μ.withDensityᵥ f