Module

Recovery.lean

Nyll.SchemeTheory.Gluing.Recovery
1 declaration indexed from sourceView source ↗

Recovering a scheme from actual gluing overlaps

Local comparison maps that cover the target and identify pairwise overlaps produce the comparison isomorphism from the glued scheme.

Imports2
  • Mathlib.AlgebraicGeometry.Gluing
  • Mathlib.CategoryTheory.Limits.Shapes.Pullback.IsPullback.Basic
Imported by2

Declarations

AlgebraicGeometry.Scheme.GlueData.exists_glueData_iso_of_overlap

Actual local comparison maps whose pairwise overlaps are the gluing overlaps construct an isomorphism from the glued scheme to the scheme they cover.

Source context 4 commands

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

noncomputable section
universe u
open CategoryTheory Limits AlgebraicGeometry
namespace AlgebraicGeometry.Scheme.GlueData
theorem exists_glueData_iso_of_overlap
    (D : Scheme.GlueData.{u}) (Z : Scheme.{u})
    (q : ∀ i, D.U i ⟶ Z) [∀ i, IsOpenImmersion (q i)]
    (hcover : ∀ z : Z, ∃ (i : D.J) (x : D.U i), q i x = z)
    (hV : ∀ i j, IsPullback (D.f i j) (D.t i j ≫ D.f j i) (q i) (q j)) :
    ∃ e : D.glued ≅ Z, ∀ i, D.ι i ≫ e.hom = q i