∀ {ι : Type u_6} {X : ι → Type u_7} [Countable ι] [inst : (i : ι) → TopologicalSpace (X i)]
  [inst_1 : (i : ι) → MeasurableSpace (X i)] [∀ (i : ι), SecondCountableTopology (X i)] [∀ (i : ι), BorelSpace (X i)],
  BorelSpace ((i : ι) → X i)