Module

Scheme_OrderedAffineCover_exists_refinement_pullback_fst_snd_of_isSeparated.lean

Nyll.AlgebraicCurves.Geometry.Schemes.Scheme_OrderedAffineCover_exists_refinement_pullback_fst_snd_of_isSeparated
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Scheme Ordered Affine Cover exists refinement pullback fst snd of is Separated

Declarations

AlgebraicGeometry.Scheme.OrderedAffineCover.exists_refinement_pullback_fst_snd_of_isSeparated
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Surrounding namespaces, section variables, and local commands at this declaration.

section ProofImplementation
namespace AlgebraicGeometry.Scheme.OrderedAffineCover
universe u
open _root_.AlgebraicCurves.Geometry.Schemes.Proofs in
open Scheme_OrderedAffineCover_exists_refinement_pullback_fst_snd_of_isSeparated in
open CategoryTheory CategoryTheory.Limits AlgebraicGeometry in
open _root_.AlgebraicGeometry.Scheme.Pullback in
theorem exists_refinement_pullback_fst_snd_of_isSeparated
    {R : Type u} [CommRing R] {A : Scheme.{u}} (f : A ⟶ Spec (CommRingCat.of R)) [IsSeparated f]
    (𝒦 : A.OrderedAffineCover) (μ : pullback f f ⟶ A) (_hμ : μ ≫ f = pullback.fst f f ≫ f) :
    ∃ (𝒲 : (pullback f f).OrderedAffineCover) (lam₁ lam₂ lam₃ : 𝒲.ι → 𝒦.ι),
      (∀ w, 𝒲.U w ≤ pullback.fst f f ⁻¹ᵁ 𝒦.U (lam₁ w)) ∧
      (∀ w, 𝒲.U w ≤ pullback.snd f f ⁻¹ᵁ 𝒦.U (lam₂ w)) ∧
      (∀ w, 𝒲.U w ≤ μ ⁻¹ᵁ 𝒦.U (lam₃ w))