Module

Scheme_Modules_epi_sheafification_map_of_locallySurjective.lean

Nyll.AlgebraicCurves.Geometry.Sheaves.Scheme_Modules_epi_sheafification_map_of_locallySurjective
2 declarations indexed from sourceView source ↗

Epimorphisms induced by locally surjective presheaf maps

Sheafification turns a locally surjective morphism of module presheaves into an epimorphism.

Imports3
  • Mathlib.Algebra.Category.ModuleCat.Presheaf.Sheafification
  • Mathlib.AlgebraicGeometry.Modules.Presheaf
  • Mathlib.AlgebraicGeometry.Modules.Sheaf
Imported by2

Declarations

AlgebraicCurves.Geometry.Sheaves.Proofs.Scheme_Modules_epi_sheafification_map_of_locallySurjective.PresheafOfModules.epi_sheafification_map_of_isLocallySurjective
Source context 14 commands

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

section ProofImplementation
namespace AlgebraicCurves.Geometry.Sheaves.Proofs
namespace Scheme_Modules_epi_sheafification_map_of_locallySurjective
universe u
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.Opposite
open _root_.TopologicalSpace
universe v v' u'
namespace PresheafOfModules
open _root_.PresheafOfModules
open _root_.PresheafOfModules
variable {C : Type u'} [Category.{v'} C] {J : GrothendieckTopology C}
  {R₀ : Cᵒᵖ ⥤ RingCat.{u}} {R : Sheaf J RingCat.{u}} (α : R₀ ⟶ R.obj)
  [Presheaf.IsLocallyInjective J α] [Presheaf.IsLocallySurjective J α]
  [HasSheafify J AddCommGrpCat.{v}] [J.WEqualsLocallyBijective AddCommGrpCat.{v}]
theorem epi_sheafification_map_of_isLocallySurjective {P Q : PresheafOfModules.{v} R₀}
    (ψ : P ⟶ Q) [Presheaf.IsLocallySurjective J ((toPresheaf R₀).map ψ)] :
    Epi ((sheafification.{v} α).map ψ)
AlgebraicGeometry.Scheme.Modules.epi_sheafification_map_of_locallySurjective
Source context 20 commands

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

section ProofImplementation
namespace AlgebraicCurves.Geometry.Sheaves.Proofs
namespace Scheme_Modules_epi_sheafification_map_of_locallySurjective
universe u
open _root_.CategoryTheory
open _root_.CategoryTheory.Limits
open _root_.AlgebraicGeometry
open _root_.Opposite
open _root_.TopologicalSpace
universe v v' u'
namespace AlgebraicGeometry
open _root_.AlgebraicGeometry
namespace Scheme
open _root_.AlgebraicGeometry.Scheme
namespace Modules
open _root_.AlgebraicGeometry.Scheme.Modules
open _root_.AlgebraicGeometry.Scheme.Modules
open _root_.AlgebraicGeometry.Scheme
open _root_.AlgebraicGeometry
variable {X : Scheme.{u}}
theorem _root_.AlgebraicGeometry.Scheme.Modules.epi_sheafification_map_of_locallySurjective {P Q :
  X.PresheafOfModules} (ψ : P ⟶ Q)
    (h : ∀ (U : X.Opens) (s : Q.obj (op U)), ∀ x ∈ U, ∃ (V : X.Opens) (i : V ≤ U),
      x ∈ V ∧ Q.map (homOfLE i).op s ∈ Set.range (ψ.app (op V))) :
    Epi ((PresheafOfModules.sheafification (𝟙 X.ringCatSheaf.obj)).map ψ)