∀ {α : Type u_1} {β : Type u_2} {γ : Type u_3} [inst : MeasurableSpace α] {K : Type u_5} [inst_1 : SMul K γ]
  [inst_2 : SMul γ β] [inst_3 : SMul K β] [IsScalarTower K γ β], IsScalarTower K γ (MeasureTheory.SimpleFunc α β)