AlgebraicCurves.Geometry.Schemes.Proofs.Scheme_Hom_map_germ_ker_ideal_eq_ker_stalkMap.PtGerm.map_germ_ker_ideal_eq_ker_stalkMap
Source context 5 commands
Surrounding namespaces, section variables, and local commands at this declaration.
section ProofImplementation
namespace AlgebraicCurves.Geometry.Schemes.Proofs.Scheme_Hom_map_germ_ker_ideal_eq_ker_stalkMap
universe u
open CategoryTheory CategoryTheory.Limits AlgebraicGeometry TopologicalSpace
namespace PtGermLean source · statement
theorem map_germ_ker_ideal_eq_ker_stalkMap {X Y : Scheme.{u}} (σ : Y ⟶ X) [IsClosedImmersion σ] (y
: Y)
(U : X.affineOpens) (hx : σ.base y ∈ (U : X.Opens)) :
Ideal.map (X.presheaf.germ (U : X.Opens) (σ.base y) hx).hom (σ.ker.ideal U) = RingHom.ker
(σ.stalkMap y).hom