∀ (R : Type u_1) (S : Type u_2) [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : Algebra R S] (p : PrimeSpectrum R)
  (q : PrimeSpectrum (p.asIdeal.Fiber S)),
  (fun q =>
        {
          asIdeal :=
            RingHom.ker
              (Algebra.TensorProduct.lift (Ideal.ResidueField.mapₐ p.asIdeal (↑q).asIdeal (Algebra.ofId R S) ⋯)
                  (IsScalarTower.toAlgHom R S (↑q).asIdeal.ResidueField) ⋯).toRingHom,
          isPrime := ⋯ })
      ((fun q => ⟨PrimeSpectrum.comap Algebra.TensorProduct.includeRight.toRingHom q, ⋯⟩) q) =
    q