∀ {α : Type u_1} {δ : Type u_4} [inst : TopologicalSpace α] {mα : MeasurableSpace α} [BorelSpace α]
  {mδ : MeasurableSpace δ} [inst_2 : LinearOrder α] [OrderTopology α] [SecondCountableTopology α] {f : δ → α},
  (∀ (x : α), MeasurableSet (f ⁻¹' Set.Ioi x)) → Measurable f