Module

ProjSpace_exists_iso_hom_comp_eq_of_isPullback_of_comp_eq_map.lean

Nyll.AlgebraicCurves.Geometry.Projective.ProjSpace_exists_iso_hom_comp_eq_of_isPullback_of_comp_eq_map
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Proj Space exists iso hom comp eq of is Pullback of comp eq map

Declarations

AlgebraicGeometry.ProjSpace.exists_iso_hom_comp_eq_of_isPullback_of_comp_eq_map
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Surrounding namespaces, section variables, and local commands at this declaration.

section ProofImplementation
namespace AlgebraicCurves.Geometry.Projective.Proofs
namespace ProjSpace_exists_iso_hom_comp_eq_of_isPullback_of_comp_eq_map
open MvPolynomial CategoryTheory CategoryTheory.Limits AlgebraicGeometry
  AlgebraicGeometry.HilbertFunctor
attribute [local instance] MvPolynomial.gradedAlgebra
theorem _root_.AlgebraicGeometry.ProjSpace.exists_iso_hom_comp_eq_of_isPullback_of_comp_eq_map
    (n : ℕ) (A B : Type) [CommRing A] [CommRing B] [Algebra A B] (Z : Scheme.{0})
    (ι : Z ⟶ Proj (MvPolynomial.homogeneousSubmodule (Fin (n + 1)) A))
    (Z₁ : Scheme.{0}) (ι₁ : Z₁ ⟶ Proj (MvPolynomial.homogeneousSubmodule (Fin (n + 1)) B)) (e₁ : Z₁
      ⟶ Z)
    (h₁ : IsPullback e₁ (ι₁ ≫ ProjSpace.π B n) (ι ≫ ProjSpace.π A n) (Spec.map (CommRingCat.ofHom
      (algebraMap A B))))
    (h₁' : e₁ ≫ ι = ι₁ ≫ ProjSpace.map A B n)
    (Z₂ : Scheme.{0}) (ι₂ : Z₂ ⟶ Proj (MvPolynomial.homogeneousSubmodule (Fin (n + 1)) B)) (e₂ : Z₂
      ⟶ Z)
    (h₂ : IsPullback e₂ (ι₂ ≫ ProjSpace.π B n) (ι ≫ ProjSpace.π A n) (Spec.map (CommRingCat.ofHom
      (algebraMap A B))))
    (h₂' : e₂ ≫ ι = ι₂ ≫ ProjSpace.map A B n) :
    ∃ φ : Z₁ ≅ Z₂, φ.hom ≫ ι₂ = ι₁ ∧ φ.hom ≫ e₂ = e₁