∀ {ι : Type u_1} [inst : LinearOrder ι] [inst_1 : LocallyFiniteOrder ι] [inst_2 : DecidableLE ι] {X : ι → Type u_2}
  {a b c : ι} (hab : a ≤ b) (hbc : b ≤ c) (s : (i : ↥(Finset.Ioc a c)) → Set (X ↑i)),
  IocProdIoc a b c ⁻¹' Set.univ.pi s = Set.univ.pi (Finset.restrict₂ ⋯ s) ×ˢ Set.univ.pi (Finset.restrict₂ ⋯ s)