∀ {α : Type u_1} {γ : Type u_2} [inst : MeasurableSpace α] {μ : MeasureTheory.Measure α} [inst_1 : TopologicalSpace γ]
  [inst_2 : AddMonoid γ] [inst_3 : ContinuousAdd γ] (f g : α →ₘ[μ] γ), (f + g).toGerm = f.toGerm + g.toGerm