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IsLocallyNoetherian (X : Scheme) : Prop where component_noetherian : ∀ (U : X.affineOpens), IsNoetherianRing Γ(X, U) := by infer_instance
class
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
IsLocallyNoetherian
A scheme `X` is locally Noetherian if `𝒪ₓ(U)` is Noetherian for all affine `U`.
isNoetherianRing_of_away : IsNoetherianRing R := by apply monotone_stabilizes_iff_noetherian.mp intro I let floc s := algebraMap R (Away (M := R) s) let suitableN s := { n : ℕ | ∀ m : ℕ, n ≤ m → (Ideal.map (floc s) (I n)) = (Ideal.map (floc s) (I m)) } let minN s := sInf (suitableN s) have hSuit : ∀ s : S, minN s ∈ suitableN s := by intro s apply Nat.sInf_mem let f : ℕ →o Ideal (Away (M := R) s) := ⟨fun n ↦ Ideal.map (floc s) (I n), fun _ _ h ↦ Ideal.map_mono (I.monotone h)⟩ exact monotone_stabilizes_iff_noetherian.mpr (hN s) f let N := Finset.sup S minN use N have hN : ∀ s : S, minN s ≤ N := fun s => Finset.le_sup s.prop intro n hn rw [IsLocalization.ideal_eq_iInf_comap_map_away hS (I N), IsLocalization.ideal_eq_iInf_comap_map_away hS (I n), iInf_subtype', iInf_subtype'] apply iInf_congr intro s congr 1 rw [← hSuit s N (hN s)] exact hSuit s n <| Nat.le_trans (hN s) hn
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isNoetherianRing_of_away
Let `R` be a ring, and `f i` a finite collection of elements of `R` generating the unit ideal. If the localization of `R` at each `f i` is Noetherian, so is `R`. We follow the proof given in [Har77], Proposition II.3.2
isLocallyNoetherian_of_affine_cover {ι} {S : ι → X.affineOpens} (hS : (⨆ i, S i : X.Opens) = ⊤) (hS' : ∀ i, IsNoetherianRing Γ(X, S i)) : IsLocallyNoetherian X := by refine ⟨fun U => ?_⟩ induction U using of_affine_open_cover S hS with | basicOpen U f hN => have := U.prop.isLocalization_basicOpen f exact IsLocalization.isNoetherianRing (.powers f) Γ(X, X.basicOpen f) hN | openCover U s _ hN => apply isNoetherianRing_of_away s ‹_› intro ⟨f, hf⟩ have : IsNoetherianRing Γ(X, X.basicOpen f) := hN ⟨f, hf⟩ have := U.prop.isLocalization_basicOpen f have hEq := IsLocalization.algEquiv (.powers f) (Localization.Away f) Γ(X, X.basicOpen f) exact isNoetherianRing_of_ringEquiv Γ(X, X.basicOpen f) hEq.symm.toRingEquiv | hU => exact hS' _
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isLocallyNoetherian_of_affine_cover
If a scheme `X` has a cover by affine opens whose sections are Noetherian rings, then `X` is locally Noetherian.
isLocallyNoetherian_iff_of_iSup_eq_top {ι} {S : ι → X.affineOpens} (hS : (⨆ i, S i : X.Opens) = ⊤) : IsLocallyNoetherian X ↔ ∀ i, IsNoetherianRing Γ(X, S i) := ⟨fun _ i => IsLocallyNoetherian.component_noetherian (S i), isLocallyNoetherian_of_affine_cover hS⟩
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isLocallyNoetherian_iff_of_iSup_eq_top
A scheme is locally Noetherian if and only if it is covered by affine opens whose sections are Noetherian rings. See [Har77], Proposition II.3.2.
isLocallyNoetherian_iff_of_affine_openCover (𝒰 : Scheme.OpenCover.{v, u} X) [∀ i, IsAffine (𝒰.X i)] : IsLocallyNoetherian X ↔ ∀ (i : 𝒰.I₀), IsNoetherianRing Γ(𝒰.X i, ⊤) := by constructor · intro h i let U := Scheme.Hom.opensRange (𝒰.f i) have := h.component_noetherian ⟨U, isAffineOpen_opensRange _⟩ apply isNoetherianRing_of_ringEquiv (R := Γ(X, U)) apply CategoryTheory.Iso.commRingCatIsoToRingEquiv exact (IsOpenImmersion.ΓIsoTop (𝒰.f i)).symm · intro hCNoeth let fS i : X.affineOpens := ⟨Scheme.Hom.opensRange (𝒰.f i), isAffineOpen_opensRange _⟩ apply isLocallyNoetherian_of_affine_cover (S := fS) · rw [← Scheme.OpenCover.iSup_opensRange 𝒰] intro i apply isNoetherianRing_of_ringEquiv (R := Γ(𝒰.X i, ⊤)) apply CategoryTheory.Iso.commRingCatIsoToRingEquiv exact IsOpenImmersion.ΓIsoTop (𝒰.f i)
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isLocallyNoetherian_iff_of_affine_openCover
A version of `isLocallyNoetherian_iff_of_iSup_eq_top` using `Scheme.OpenCover`.
isLocallyNoetherian_of_isOpenImmersion {Y : Scheme} (f : X ⟶ Y) [IsOpenImmersion f] [IsLocallyNoetherian Y] : IsLocallyNoetherian X := by refine ⟨fun U => ?_⟩ let V : Y.affineOpens := ⟨f ''ᵁ U, IsAffineOpen.image_of_isOpenImmersion U.prop _⟩ suffices Γ(X, U) ≅ Γ(Y, V) by convert isNoetherianRing_of_ringEquiv (R := Γ(Y, V)) _ · apply CategoryTheory.Iso.commRingCatIsoToRingEquiv exact this.symm · exact IsLocallyNoetherian.component_noetherian V rw [← Scheme.Hom.preimage_image_eq f U] trans · apply IsOpenImmersion.ΓIso · suffices Scheme.Hom.opensRange f ⊓ V = V by rw [this] rw [← Opens.coe_inj] rw [Opens.coe_inf, Scheme.Hom.coe_opensRange, IsOpenMap.coe_functor_obj, Set.inter_eq_right, Set.image_subset_iff, Set.preimage_range] exact Set.subset_univ _
lemma
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isLocallyNoetherian_of_isOpenImmersion
null
isLocallyNoetherian_iff_openCover (𝒰 : Scheme.OpenCover X) : IsLocallyNoetherian X ↔ ∀ (i : 𝒰.I₀), IsLocallyNoetherian (𝒰.X i) := by constructor · intro h i exact isLocallyNoetherian_of_isOpenImmersion (𝒰.f i) · rw [isLocallyNoetherian_iff_of_affine_openCover (𝒰 := 𝒰.affineRefinement.openCover)] intro h i exact @isNoetherianRing_of_ringEquiv _ _ _ _ (IsOpenImmersion.ΓIsoTop (PreZeroHypercover.f _ i.2)).symm.commRingCatIsoToRingEquiv (IsLocallyNoetherian.component_noetherian ⟨_, isAffineOpen_opensRange _⟩)
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isLocallyNoetherian_iff_openCover
If `𝒰` is an open cover of a scheme `X`, then `X` is locally Noetherian if and only if `𝒰.X i` are all locally Noetherian.
@[mk_iff] IsNoetherian (X : Scheme) : Prop extends IsLocallyNoetherian X, CompactSpace X
class
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
IsNoetherian
If `R` is a Noetherian ring, `Spec R` is a Noetherian topological space. -/ instance {R : CommRingCat} [IsNoetherianRing R] : NoetherianSpace (Spec R) := by convert PrimeSpectrum.instNoetherianSpace (R := R) lemma noetherianSpace_of_isAffine [IsAffine X] [IsNoetherianRing Γ(X, ⊤)] : NoetherianSpace X := (noetherianSpace_iff_of_homeomorph X.isoSpec.inv.homeomorph).mp inferInstance lemma noetherianSpace_of_isAffineOpen (U : X.Opens) (hU : IsAffineOpen U) [IsNoetherianRing Γ(X, U)] : NoetherianSpace U := by have : IsNoetherianRing Γ(U, ⊤) := isNoetherianRing_of_ringEquiv _ (Scheme.restrictFunctorΓ.app (op U)).symm.commRingCatIsoToRingEquiv exact @noetherianSpace_of_isAffine _ hU _ /-- Any open immersion `Z ⟶ X` with `X` locally Noetherian is quasi-compact. -/ @[stacks 01OX] instance (priority := 100) {Z : Scheme} [IsLocallyNoetherian X] {f : Z ⟶ X} [IsOpenImmersion f] : QuasiCompact f := by apply (quasiCompact_iff_forall_affine f).mpr intro U hU rw [Opens.map_coe, ← Set.preimage_inter_range] apply f.isOpenEmbedding.isInducing.isCompact_preimage' · apply (noetherianSpace_set_iff _).mp · convert noetherianSpace_of_isAffineOpen U hU apply IsLocallyNoetherian.component_noetherian ⟨U, hU⟩ · exact Set.inter_subset_left · exact Set.inter_subset_right /-- A locally Noetherian scheme is quasi-separated. -/ @[stacks 01OY] instance (priority := 100) IsLocallyNoetherian.quasiSeparatedSpace [IsLocallyNoetherian X] : QuasiSeparatedSpace X := by apply (quasiSeparatedSpace_iff_affine X).mpr intro U V have hInd := U.2.fromSpec.isOpenEmbedding.isInducing apply (hInd.isCompact_preimage_iff ?_).mp · rw [← Set.preimage_inter_range, IsAffineOpen.range_fromSpec, Set.inter_comm] apply hInd.isCompact_preimage' · apply (noetherianSpace_set_iff _).mp · convert noetherianSpace_of_isAffineOpen U.1 U.2 apply IsLocallyNoetherian.component_noetherian · exact Set.inter_subset_left · rw [IsAffineOpen.range_fromSpec] exact Set.inter_subset_left · rw [IsAffineOpen.range_fromSpec] exact Set.inter_subset_left /-- A scheme `X` is Noetherian if it is locally Noetherian and compact.
isNoetherian_iff_of_finite_iSup_eq_top {ι} [Finite ι] {S : ι → X.affineOpens} (hS : (⨆ i, S i : X.Opens) = ⊤) : IsNoetherian X ↔ ∀ i, IsNoetherianRing Γ(X, S i) := by constructor · intro h i apply (isLocallyNoetherian_iff_of_iSup_eq_top hS).mp exact h.toIsLocallyNoetherian · intro h convert IsNoetherian.mk · exact isLocallyNoetherian_of_affine_cover hS h · constructor rw [← Opens.coe_top, ← hS, Opens.iSup_mk] apply isCompact_iUnion intro i apply isCompact_iff_isCompact_univ.mpr convert CompactSpace.isCompact_univ have : NoetherianSpace (S i) := by apply noetherianSpace_of_isAffineOpen (S i).1 (S i).2 apply NoetherianSpace.compactSpace (S i)
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isNoetherian_iff_of_finite_iSup_eq_top
A scheme is Noetherian if and only if it is covered by finitely many affine opens whose sections are Noetherian rings.
isNoetherian_iff_of_finite_affine_openCover {𝒰 : Scheme.OpenCover.{v, u} X} [Finite 𝒰.I₀] [∀ i, IsAffine (𝒰.X i)] : IsNoetherian X ↔ ∀ (i : 𝒰.I₀), IsNoetherianRing Γ(𝒰.X i, ⊤) := by constructor · intro h i apply (isLocallyNoetherian_iff_of_affine_openCover _).mp exact h.toIsLocallyNoetherian · intro hNoeth convert IsNoetherian.mk · exact (isLocallyNoetherian_iff_of_affine_openCover _).mpr hNoeth · exact Scheme.OpenCover.compactSpace 𝒰
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isNoetherian_iff_of_finite_affine_openCover
A version of `isNoetherian_iff_of_finite_iSup_eq_top` using `Scheme.OpenCover`.
isNoetherian_Spec {R : CommRingCat} : IsNoetherian (Spec R) ↔ IsNoetherianRing R := ⟨fun _ => inferInstance, fun _ => inferInstance⟩
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
isNoetherian_Spec
A Noetherian scheme has a Noetherian underlying topological space. -/ @[stacks 01OZ] instance (priority := 100) IsNoetherian.noetherianSpace [IsNoetherian X] : NoetherianSpace X := by apply TopologicalSpace.noetherian_univ_iff.mp let 𝒰 := X.affineCover.finiteSubcover rw [← 𝒰.iUnion_range] suffices ∀ i : 𝒰.I₀, NoetherianSpace (Set.range <| (𝒰.f i).base) by apply NoetherianSpace.iUnion intro i have : IsAffine (𝒰.X i) := by rw [X.affineCover.finiteSubcover_X] apply Scheme.isAffine_affineCover let U : X.affineOpens := ⟨Scheme.Hom.opensRange (𝒰.f i), isAffineOpen_opensRange _⟩ convert noetherianSpace_of_isAffineOpen U.1 U.2 apply IsLocallyNoetherian.component_noetherian /-- Any morphism of schemes `f : X ⟶ Y` with `X` Noetherian is quasi-compact. -/ @[stacks 01P0] instance (priority := 100) quasiCompact_of_noetherianSpace_source {X Y : Scheme} [NoetherianSpace X] (f : X ⟶ Y) : QuasiCompact f := ⟨fun _ _ _ => NoetherianSpace.isCompact _⟩ /-- If `R` is a Noetherian ring, `Spec R` is a locally Noetherian scheme. -/ instance {R : CommRingCat} [IsNoetherianRing R] : IsLocallyNoetherian (Spec R) := by apply isLocallyNoetherian_of_affine_cover (ι := Fin 1) (S := fun _ => ⟨⊤, isAffineOpen_top (Spec R)⟩) · exact iSup_const · intro apply isNoetherianRing_of_ringEquiv R apply CategoryTheory.Iso.commRingCatIsoToRingEquiv exact (Scheme.ΓSpecIso R).symm instance (priority := 100) {R : CommRingCat} [IsLocallyNoetherian (Spec R)] : IsNoetherianRing R := by have := IsLocallyNoetherian.component_noetherian ⟨⊤, AlgebraicGeometry.isAffineOpen_top (Spec R)⟩ apply isNoetherianRing_of_ringEquiv Γ(Spec R, ⊤) apply CategoryTheory.Iso.commRingCatIsoToRingEquiv exact Scheme.ΓSpecIso R /-- If `R` is a Noetherian ring, `Spec R` is a Noetherian scheme. -/ instance {R : CommRingCat} [IsNoetherianRing R] : IsNoetherian (Spec R) where instance {R} [CommRing R] [IsNoetherianRing R] : IsNoetherian Spec(R) := by suffices IsNoetherianRing (CommRingCat.of R) by infer_instance assumption instance [IsLocallyNoetherian X] {x : X} : IsNoetherianRing (X.presheaf.stalk x) := by obtain ⟨U, hU, hU2, hU3⟩ := exists_isAffineOpen_mem_and_subset (U := ⊤) (x := x) (by aesop) have := AlgebraicGeometry.IsAffineOpen.isLocalization_stalk hU ⟨x, hU2⟩ exact @IsLocalization.isNoetherianRing _ _ (hU.primeIdealOf ⟨x, hU2⟩).asIdeal.primeCompl (X.presheaf.stalk x) _ (X.presheaf.algebra_section_stalk ⟨x, hU2⟩) this (IsLocallyNoetherian.component_noetherian ⟨U, hU⟩) /-- `R` is a Noetherian ring if and only if `Spec R` is a Noetherian scheme.
@[stacks 0BA8] finite_irreducibleComponents_of_isNoetherian [IsNoetherian X] : (irreducibleComponents X).Finite := NoetherianSpace.finite_irreducibleComponents
theorem
AlgebraicGeometry
[ "Mathlib.AlgebraicGeometry.Morphisms.QuasiSeparated", "Mathlib.RingTheory.Localization.Submodule", "Mathlib.RingTheory.Spectrum.Prime.Noetherian" ]
Mathlib/AlgebraicGeometry/Noetherian.lean
finite_irreducibleComponents_of_isNoetherian
A Noetherian scheme has a finite number of irreducible components.
IsOpenImmersion : MorphismProperty (Scheme.{u}) := fun _ _ f ↦ LocallyRingedSpace.IsOpenImmersion f.toLRSHom
abbrev
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
IsOpenImmersion
A morphism of Schemes is an open immersion if it is an open immersion as a morphism of LocallyRingedSpaces
IsOpenImmersion.comp {X Y Z : Scheme.{u}} (f : X ⟶ Y) (g : Y ⟶ Z) [IsOpenImmersion f] [IsOpenImmersion g] : IsOpenImmersion (f ≫ g) := LocallyRingedSpace.IsOpenImmersion.comp f.toLRSHom g.toLRSHom
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
IsOpenImmersion.comp
null
protected scheme (X : LocallyRingedSpace.{u}) (h : ∀ x : X, ∃ (R : CommRingCat) (f : Spec.toLocallyRingedSpace.obj (op R) ⟶ X), (x ∈ Set.range f.base :) ∧ LocallyRingedSpace.IsOpenImmersion f) : Scheme where toLocallyRingedSpace := X local_affine := by intro x obtain ⟨R, f, h₁, h₂⟩ := h x refine ⟨⟨⟨_, h₂.base_open.isOpen_range⟩, h₁⟩, R, ⟨?_⟩⟩ apply LocallyRingedSpace.isoOfSheafedSpaceIso refine SheafedSpace.forgetToPresheafedSpace.preimageIso ?_ apply PresheafedSpace.IsOpenImmersion.isoOfRangeEq (PresheafedSpace.ofRestrict _ _) f.1 · exact Subtype.range_coe_subtype · exact Opens.isOpenEmbedding _
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
scheme
To show that a locally ringed space is a scheme, it suffices to show that it has a jointly surjective family of open immersions from affine schemes.
IsOpenImmersion.isOpen_range {X Y : Scheme.{u}} (f : X ⟶ Y) [H : IsOpenImmersion f] : IsOpen (Set.range f.base) := H.base_open.isOpen_range
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
IsOpenImmersion.isOpen_range
null
isOpenEmbedding : IsOpenEmbedding f.base := H.base_open
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isOpenEmbedding
null
@[simps] opensRange : Y.Opens := ⟨_, f.isOpenEmbedding.isOpen_range⟩
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
opensRange
The image of an open immersion as an open set.
opensFunctor : X.Opens ⥤ Y.Opens := LocallyRingedSpace.IsOpenImmersion.opensFunctor f.toLRSHom
abbrev
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
opensFunctor
The functor `opens X ⥤ opens Y` associated with an open immersion `f : X ⟶ Y`.
appIso (U) : Γ(Y, f ''ᵁ U) ≅ Γ(X, U) := (asIso <| LocallyRingedSpace.IsOpenImmersion.invApp f.toLRSHom U).symm @[reassoc (attr := simp)]
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
appIso
`f ''ᵁ U` is notation for the image (as an open set) of `U` under an open immersion `f`. -/ scoped[AlgebraicGeometry] notation3:90 f:91 " ''ᵁ " U:90 => (Scheme.Hom.opensFunctor f).obj U lemma image_le_image_of_le {U V : X.Opens} (e : U ≤ V) : f ''ᵁ U ≤ f ''ᵁ V := by rintro a ⟨u, hu, rfl⟩ exact Set.mem_image_of_mem (⇑f.base) (e hu) @[simp] lemma opensFunctor_map_homOfLE {U V : X.Opens} (e : U ≤ V) : (Scheme.Hom.opensFunctor f).map (homOfLE e) = homOfLE (f.image_le_image_of_le e) := rfl @[simp] lemma image_top_eq_opensRange : f ''ᵁ ⊤ = f.opensRange := by apply Opens.ext simp lemma opensRange_comp {X Y Z : Scheme} (f : X ⟶ Y) (g : Y ⟶ Z) [IsOpenImmersion f] [IsOpenImmersion g] : (f ≫ g).opensRange = g ''ᵁ f.opensRange := TopologicalSpace.Opens.ext (Set.range_comp g.base f.base) lemma opensRange_of_isIso {X Y : Scheme} (f : X ⟶ Y) [IsIso f] : f.opensRange = ⊤ := TopologicalSpace.Opens.ext (Set.range_eq_univ.mpr f.homeomorph.surjective) lemma opensRange_comp_of_isIso {X Y Z : Scheme} (f : X ⟶ Y) (g : Y ⟶ Z) [IsIso f] [IsOpenImmersion g] : (f ≫ g).opensRange = g.opensRange := by rw [opensRange_comp, opensRange_of_isIso, image_top_eq_opensRange] @[simp] lemma preimage_image_eq (U : X.Opens) : f ⁻¹ᵁ f ''ᵁ U = U := by apply Opens.ext simp [Set.preimage_image_eq _ f.isOpenEmbedding.injective] lemma image_le_image_iff (f : X ⟶ Y) [IsOpenImmersion f] (U U' : X.Opens) : f ''ᵁ U ≤ f ''ᵁ U' ↔ U ≤ U' := by refine ⟨fun h ↦ ?_, image_le_image_of_le f⟩ rw [← preimage_image_eq f U, ← preimage_image_eq f U'] apply preimage_le_preimage_of_le f h lemma image_preimage_eq_opensRange_inter (U : Y.Opens) : f ''ᵁ f ⁻¹ᵁ U = f.opensRange ⊓ U := by apply Opens.ext simp [Set.image_preimage_eq_range_inter] lemma image_injective : Function.Injective (f ''ᵁ ·) := by intro U V hUV simpa using congrArg (f ⁻¹ᵁ ·) hUV lemma image_iSup {ι : Sort*} (s : ι → X.Opens) : (f ''ᵁ ⨆ (i : ι), s i) = ⨆ (i : ι), f ''ᵁ s i := by ext : 1 simp [Set.image_iUnion] lemma image_iSup₂ {ι : Sort*} {κ : ι → Sort*} (s : (i : ι) → κ i → X.Opens) : (f ''ᵁ ⨆ (i : ι), ⨆ (j : κ i), s i j) = ⨆ (i : ι), ⨆ (j : κ i), f ''ᵁ s i j := by ext : 1 simp [Set.image_iUnion₂] @[simp] lemma map_mem_image_iff {X Y : Scheme} (f : X ⟶ Y) [IsOpenImmersion f] {U : X.Opens} {x : X} : f.base x ∈ f ''ᵁ U ↔ x ∈ U := f.isOpenEmbedding.injective.mem_set_image @[simp] lemma preimage_opensRange {X Y : Scheme.{u}} (f : X.Hom Y) [IsOpenImmersion f] : f ⁻¹ᵁ f.opensRange = ⊤ := by simp [Scheme.Hom.opensRange] lemma isIso_app (V : Y.Opens) (hV : V ≤ f.opensRange) : IsIso (f.app V) := by rw [show V = f ''ᵁ f ⁻¹ᵁ V from Opens.ext (Set.image_preimage_eq_of_subset hV).symm] infer_instance /-- The isomorphism `Γ(Y, f(U)) ≅ Γ(X, U)` induced by an open immersion `f : X ⟶ Y`.
appIso_inv_naturality {U V : X.Opens} (i : op U ⟶ op V) : X.presheaf.map i ≫ (f.appIso V).inv = (f.appIso U).inv ≫ Y.presheaf.map (f.opensFunctor.op.map i) := PresheafedSpace.IsOpenImmersion.inv_naturality _ _
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
appIso_inv_naturality
null
appIso_hom (U) : (f.appIso U).hom = f.app (f ''ᵁ U) ≫ X.presheaf.map (eqToHom (preimage_image_eq f U).symm).op := (PresheafedSpace.IsOpenImmersion.inv_invApp f.toPshHom U).trans (by rw [eqToHom_op])
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
appIso_hom
null
appIso_hom' (U) : (f.appIso U).hom = f.appLE (f ''ᵁ U) U (preimage_image_eq f U).ge := f.appIso_hom U @[reassoc (attr := simp)]
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
appIso_hom'
null
app_appIso_inv (U) : f.app U ≫ (f.appIso (f ⁻¹ᵁ U)).inv = Y.presheaf.map (homOfLE (Set.image_preimage_subset f.base U.1)).op := PresheafedSpace.IsOpenImmersion.app_invApp _ _
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
app_appIso_inv
null
@[reassoc] app_invApp' (U) (hU : U ≤ f.opensRange) : f.app U ≫ (f.appIso (f ⁻¹ᵁ U)).inv = Y.presheaf.map (eqToHom (Opens.ext <| by simpa [Set.image_preimage_eq_inter_range])).op := PresheafedSpace.IsOpenImmersion.app_invApp _ _ @[reassoc (attr := simp), elementwise nosimp]
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
app_invApp'
A variant of `app_invApp` that gives an `eqToHom` instead of `homOfLE`.
appIso_inv_app (U) : (f.appIso U).inv ≫ f.app (f ''ᵁ U) = X.presheaf.map (eqToHom (preimage_image_eq f U)).op := (PresheafedSpace.IsOpenImmersion.invApp_app _ _).trans (by rw [eqToHom_op]) @[reassoc (attr := simp), elementwise nosimp]
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
appIso_inv_app
null
appLE_appIso_inv {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] {U : Y.Opens} {V : X.Opens} (e : V ≤ f ⁻¹ᵁ U) : f.appLE U V e ≫ (f.appIso V).inv = Y.presheaf.map (homOfLE <| (f.image_le_image_of_le e).trans (f.image_preimage_eq_opensRange_inter U ▸ inf_le_right)).op := by simp only [appLE, Category.assoc, appIso_inv_naturality, Functor.op_obj, Functor.op_map, Quiver.Hom.unop_op, opensFunctor_map_homOfLE, app_appIso_inv_assoc, Opens.carrier_eq_coe] rw [← Functor.map_comp] rfl @[reassoc (attr := simp)]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
appLE_appIso_inv
null
appIso_inv_appLE {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] {U V : X.Opens} (e : V ≤ f ⁻¹ᵁ f ''ᵁ U) : (f.appIso U).inv ≫ f.appLE (f ''ᵁ U) V e = X.presheaf.map (homOfLE (by rwa [preimage_image_eq] at e)).op := by simp only [appLE, appIso_inv_app_assoc, eqToHom_op] rw [← Functor.map_comp] rfl
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
appIso_inv_appLE
null
@[simps] IsOpenImmersion.opensEquiv {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] : X.Opens ≃ { U : Y.Opens // U ≤ f.opensRange } where toFun U := ⟨f ''ᵁ U, Set.image_subset_range _ _⟩ invFun U := f ⁻¹ᵁ U left_inv _ := Opens.ext (Set.preimage_image_eq _ f.isOpenEmbedding.injective) right_inv U := Subtype.ext (Opens.ext (Set.image_preimage_eq_of_subset U.2))
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
IsOpenImmersion.opensEquiv
The open sets of an open subscheme corresponds to the open sets containing in the image.
basic_open_isOpenImmersion {R : CommRingCat.{u}} (f : R) : IsOpenImmersion (Spec.map (CommRingCat.ofHom (algebraMap R (Localization.Away f)))) := by apply SheafedSpace.IsOpenImmersion.of_stalk_iso (H := ?_) · exact (PrimeSpectrum.localization_away_isOpenEmbedding (Localization.Away f) f :) · intro x exact Spec_map_localization_isIso R (Submonoid.powers f) x
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
basic_open_isOpenImmersion
null
_root_.AlgebraicGeometry.IsOpenImmersion.of_isLocalization {R S} [CommRing R] [CommRing S] [Algebra R S] (f : R) [IsLocalization.Away f S] : IsOpenImmersion (Spec.map (CommRingCat.ofHom (algebraMap R S))) := by have e := (IsLocalization.algEquiv (.powers f) S (Localization.Away f)).symm.toAlgHom.comp_algebraMap rw [← e, CommRingCat.ofHom_comp, Spec.map_comp] have H : IsIso (CommRingCat.ofHom (IsLocalization.algEquiv (Submonoid.powers f) S (Localization.Away f)).symm.toAlgHom.toRingHom) := by exact inferInstanceAs (IsIso <| (IsLocalization.algEquiv (Submonoid.powers f) S (Localization.Away f)).toRingEquiv.toCommRingCatIso.inv) simp only [AlgEquiv.toAlgHom_eq_coe, AlgHom.toRingHom_eq_coe, AlgEquiv.toAlgHom_toRingHom] at H ⊢ infer_instance
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
_root_.AlgebraicGeometry.IsOpenImmersion.of_isLocalization
null
exists_affine_mem_range_and_range_subset {X : Scheme.{u}} {x : X} {U : X.Opens} (hxU : x ∈ U) : ∃ (R : CommRingCat) (f : Spec R ⟶ X), IsOpenImmersion f ∧ x ∈ Set.range f.base ∧ Set.range f.base ⊆ U := by obtain ⟨⟨V, hxV⟩, R, ⟨e⟩⟩ := X.2 x have : e.hom.base ⟨x, hxV⟩ ∈ (Opens.map (e.inv.base ≫ V.inclusion')).obj U := show ((e.hom ≫ e.inv).base ⟨x, hxV⟩).1 ∈ U from e.hom_inv_id ▸ hxU obtain ⟨_, ⟨_, ⟨r : R, rfl⟩, rfl⟩, hr, hr'⟩ := PrimeSpectrum.isBasis_basic_opens.exists_subset_of_mem_open this (Opens.is_open' _) let f : Spec(Localization.Away r) ⟶ X := Spec.map (CommRingCat.ofHom (algebraMap R (Localization.Away r))) ≫ ⟨e.inv ≫ X.ofRestrict _⟩ refine ⟨.of (Localization.Away r), f, inferInstance, ?_⟩ rw [Scheme.comp_base, TopCat.coe_comp, Set.range_comp] erw [PrimeSpectrum.localization_away_comap_range (Localization.Away r) r] exact ⟨⟨_, hr, congr(($(e.hom_inv_id).base ⟨x, hxV⟩).1)⟩, Set.image_subset_iff.mpr hr'⟩
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
exists_affine_mem_range_and_range_subset
null
toScheme : Scheme := by apply LocallyRingedSpace.IsOpenImmersion.scheme (toLocallyRingedSpace _ f) intro x obtain ⟨R, i, _, h₁, h₂⟩ := Scheme.exists_affine_mem_range_and_range_subset (U := ⟨_, H.base_open.isOpen_range⟩) ⟨x, rfl⟩ refine ⟨R, LocallyRingedSpace.IsOpenImmersion.lift (toLocallyRingedSpaceHom _ f) _ h₂, ?_, ?_⟩ · rw [LocallyRingedSpace.IsOpenImmersion.lift_range]; exact h₁ · delta LocallyRingedSpace.IsOpenImmersion.lift; infer_instance @[simp]
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
toScheme
If `X ⟶ Y` is an open immersion, and `Y` is a scheme, then so is `X`.
toScheme_toLocallyRingedSpace : (toScheme Y f).toLocallyRingedSpace = toLocallyRingedSpace Y.1 f := rfl
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
toScheme_toLocallyRingedSpace
null
toSchemeHom : toScheme Y f ⟶ Y := ⟨toLocallyRingedSpaceHom _ f⟩ @[simp]
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
toSchemeHom
If `X ⟶ Y` is an open immersion of PresheafedSpaces, and `Y` is a Scheme, we can upgrade it into a morphism of Schemes.
toSchemeHom_toPshHom : (toSchemeHom Y f).toPshHom = f := rfl
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
toSchemeHom_toPshHom
null
toSchemeHom_isOpenImmersion : AlgebraicGeometry.IsOpenImmersion (toSchemeHom Y f) := H
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
toSchemeHom_isOpenImmersion
null
scheme_eq_of_locallyRingedSpace_eq {X Y : Scheme.{u}} (H : X.toLocallyRingedSpace = Y.toLocallyRingedSpace) : X = Y := by cases X; cases Y; congr
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
scheme_eq_of_locallyRingedSpace_eq
null
scheme_toScheme {X Y : Scheme.{u}} (f : X ⟶ Y) [AlgebraicGeometry.IsOpenImmersion f] : toScheme Y f.toPshHom = X := by apply scheme_eq_of_locallyRingedSpace_eq exact locallyRingedSpace_toLocallyRingedSpace f.toLRSHom
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
scheme_toScheme
null
@[simps! -isSimp carrier, simps! presheaf_obj] Scheme.restrict : Scheme := { PresheafedSpace.IsOpenImmersion.toScheme X (X.toPresheafedSpace.ofRestrict h) with toPresheafedSpace := X.toPresheafedSpace.restrict h }
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
Scheme.restrict
The restriction of a Scheme along an open embedding.
Scheme.restrict_toPresheafedSpace : (X.restrict h).toPresheafedSpace = X.toPresheafedSpace.restrict h := rfl
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
Scheme.restrict_toPresheafedSpace
null
@[simps! toLRSHom_base, simps! -isSimp toLRSHom_c_app] Scheme.ofRestrict : X.restrict h ⟶ X := ⟨X.toLocallyRingedSpace.ofRestrict h⟩ @[simp]
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
Scheme.ofRestrict
The canonical map from the restriction to the subspace.
Scheme.ofRestrict_app (V) : (X.ofRestrict h).app V = X.presheaf.map (h.isOpenMap.adjunction.counit.app V).op := rfl
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
Scheme.ofRestrict_app
null
IsOpenImmersion.ofRestrict : IsOpenImmersion (X.ofRestrict h) := show PresheafedSpace.IsOpenImmersion (X.toPresheafedSpace.ofRestrict h) by infer_instance @[simp]
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
IsOpenImmersion.ofRestrict
null
Scheme.ofRestrict_appLE (V W e) : (X.ofRestrict h).appLE V W e = X.presheaf.map (homOfLE (show X.ofRestrict h ''ᵁ _ ≤ _ by exact Set.image_subset_iff.mpr e)).op := by dsimp [Hom.appLE] exact (X.presheaf.map_comp _ _).symm @[simp]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
Scheme.ofRestrict_appLE
null
Scheme.ofRestrict_appIso (U) : (X.ofRestrict h).appIso U = Iso.refl _ := by ext1 simp only [restrict_presheaf_obj, Hom.appIso_hom', ofRestrict_appLE, homOfLE_refl, op_id, CategoryTheory.Functor.map_id, Iso.refl_hom] @[simp]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
Scheme.ofRestrict_appIso
null
Scheme.restrict_presheaf_map (V W) (i : V ⟶ W) : (X.restrict h).presheaf.map i = X.presheaf.map (homOfLE (show X.ofRestrict h ''ᵁ W.unop ≤ X.ofRestrict h ''ᵁ V.unop from Set.image_mono i.unop.le)).op := rfl
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
Scheme.restrict_presheaf_map
null
to_iso {X Y : Scheme.{u}} (f : X ⟶ Y) [h : IsOpenImmersion f] [Epi f.base] : IsIso f := @isIso_of_reflects_iso _ _ _ _ _ _ f (Scheme.forgetToLocallyRingedSpace ⋙ LocallyRingedSpace.forgetToSheafedSpace ⋙ SheafedSpace.forgetToPresheafedSpace) (@PresheafedSpace.IsOpenImmersion.to_iso _ _ _ _ f.toPshHom h _) _
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
to_iso
null
of_stalk_iso {X Y : Scheme.{u}} (f : X ⟶ Y) (hf : IsOpenEmbedding f.base) [∀ x, IsIso (f.stalkMap x)] : IsOpenImmersion f := haveI (x : X) : IsIso (f.toShHom.stalkMap x) := inferInstanceAs <| IsIso (f.stalkMap x) SheafedSpace.IsOpenImmersion.of_stalk_iso f.toShHom hf
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
of_stalk_iso
null
stalk_iso {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] (x : X) : IsIso (f.stalkMap x) := inferInstanceAs <| IsIso (f.toLRSHom.stalkMap x)
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
stalk_iso
null
of_comp {X Y Z : Scheme.{u}} (f : X ⟶ Y) (g : Y ⟶ Z) [IsOpenImmersion g] [IsOpenImmersion (f ≫ g)] : IsOpenImmersion f := haveI (x : X) : IsIso (f.stalkMap x) := haveI : IsIso (g.stalkMap (f.base x) ≫ f.stalkMap x) := by rw [← Scheme.stalkMap_comp] infer_instance IsIso.of_isIso_comp_left (f := g.stalkMap (f.base x)) _ IsOpenImmersion.of_stalk_iso _ <| IsOpenEmbedding.of_comp _ (Scheme.Hom.isOpenEmbedding g) (Scheme.Hom.isOpenEmbedding (f ≫ g))
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
of_comp
null
iff_stalk_iso {X Y : Scheme.{u}} (f : X ⟶ Y) : IsOpenImmersion f ↔ IsOpenEmbedding f.base ∧ ∀ x, IsIso (f.stalkMap x) := ⟨fun H => ⟨H.1, fun x ↦ inferInstanceAs <| IsIso (f.toPshHom.stalkMap x)⟩, fun ⟨h, _⟩ => IsOpenImmersion.of_stalk_iso f h⟩
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
iff_stalk_iso
null
_root_.AlgebraicGeometry.isIso_iff_isOpenImmersion {X Y : Scheme.{u}} (f : X ⟶ Y) : IsIso f ↔ IsOpenImmersion f ∧ Epi f.base := ⟨fun _ => ⟨inferInstance, inferInstance⟩, fun ⟨_, _⟩ => IsOpenImmersion.to_iso f⟩
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
_root_.AlgebraicGeometry.isIso_iff_isOpenImmersion
null
_root_.AlgebraicGeometry.isIso_iff_stalk_iso {X Y : Scheme.{u}} (f : X ⟶ Y) : IsIso f ↔ IsIso f.base ∧ ∀ x, IsIso (f.stalkMap x) := by rw [isIso_iff_isOpenImmersion, IsOpenImmersion.iff_stalk_iso, and_comm, ← and_assoc] refine and_congr ⟨?_, ?_⟩ Iff.rfl · rintro ⟨h₁, h₂⟩ convert_to IsIso (TopCat.isoOfHomeo (Equiv.toHomeomorphOfContinuousOpen (.ofBijective _ ⟨h₂.injective, (TopCat.epi_iff_surjective _).mp h₁⟩) h₂.continuous h₂.isOpenMap)).hom infer_instance · intro H; exact ⟨inferInstance, (TopCat.homeoOfIso (asIso f.base)).isOpenEmbedding⟩
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
_root_.AlgebraicGeometry.isIso_iff_stalk_iso
null
isoRestrict : X ≅ (Z.restrict H.base_open :) := Scheme.fullyFaithfulForgetToLocallyRingedSpace.preimageIso (LocallyRingedSpace.IsOpenImmersion.isoRestrict f.toLRSHom) local notation "forget" => Scheme.forgetToLocallyRingedSpace
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isoRestrict
An open immersion induces an isomorphism from the domain onto the image
mono : Mono f := Scheme.forgetToLocallyRingedSpace.mono_of_mono_map (show Mono f.toLRSHom by infer_instance)
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
mono
null
le_monomorphisms : IsOpenImmersion ≤ MorphismProperty.monomorphisms Scheme.{u} := fun _ _ _ _ ↦ MorphismProperty.monomorphisms.infer_property _
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
le_monomorphisms
null
forget_map_isOpenImmersion : LocallyRingedSpace.IsOpenImmersion ((forget).map f) := ⟨H.base_open, H.c_iso⟩
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
forget_map_isOpenImmersion
null
hasLimit_cospan_forget_of_left : HasLimit (cospan f g ⋙ Scheme.forgetToLocallyRingedSpace) := by rw [hasLimit_iff_of_iso (diagramIsoCospan _)] exact inferInstanceAs (HasLimit (cospan ((forget).map f) ((forget).map g))) open CategoryTheory.Limits.WalkingCospan
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
hasLimit_cospan_forget_of_left
null
hasLimit_cospan_forget_of_left' : HasLimit (cospan ((cospan f g ⋙ forget).map Hom.inl) ((cospan f g ⋙ forget).map Hom.inr)) := show HasLimit (cospan ((forget).map f) ((forget).map g)) from inferInstance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
hasLimit_cospan_forget_of_left'
null
hasLimit_cospan_forget_of_right : HasLimit (cospan g f ⋙ forget) := by rw [hasLimit_iff_of_iso (diagramIsoCospan _)] exact inferInstanceAs (HasLimit (cospan ((forget).map g) ((forget).map f)))
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
hasLimit_cospan_forget_of_right
null
hasLimit_cospan_forget_of_right' : HasLimit (cospan ((cospan g f ⋙ forget).map Hom.inl) ((cospan g f ⋙ forget).map Hom.inr)) := show HasLimit (cospan ((forget).map g) ((forget).map f)) from inferInstance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
hasLimit_cospan_forget_of_right'
null
forgetCreatesPullbackOfLeft : CreatesLimit (cospan f g) forget := createsLimitOfFullyFaithfulOfIso (PresheafedSpace.IsOpenImmersion.toScheme Y (pullback.snd f.toLRSHom g.toLRSHom).toShHom) (eqToIso (by simp) ≪≫ HasLimit.isoOfNatIso (diagramIsoCospan _).symm)
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
forgetCreatesPullbackOfLeft
null
forgetCreatesPullbackOfRight : CreatesLimit (cospan g f) forget := createsLimitOfFullyFaithfulOfIso (PresheafedSpace.IsOpenImmersion.toScheme Y (pullback.fst g.toLRSHom f.toLRSHom).1) (eqToIso (by simp) ≪≫ HasLimit.isoOfNatIso (diagramIsoCospan _).symm)
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
forgetCreatesPullbackOfRight
null
forget_preservesOfLeft : PreservesLimit (cospan f g) forget := CategoryTheory.preservesLimit_of_createsLimit_and_hasLimit _ _
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
forget_preservesOfLeft
null
forget_preservesOfRight : PreservesLimit (cospan g f) forget := preservesPullback_symmetry _ _ _
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
forget_preservesOfRight
null
hasPullback_of_left : HasPullback f g := hasLimit_of_created (cospan f g) forget
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
hasPullback_of_left
null
hasPullback_of_right : HasPullback g f := hasLimit_of_created (cospan g f) forget
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
hasPullback_of_right
null
pullback_snd_of_left : IsOpenImmersion (pullback.snd f g) := by have := PreservesPullback.iso_hom_snd forget f g dsimp only [Scheme.forgetToLocallyRingedSpace, inducedFunctor_map] at this change LocallyRingedSpace.IsOpenImmersion _ rw [← this] infer_instance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
pullback_snd_of_left
null
pullback_fst_of_right : IsOpenImmersion (pullback.fst g f) := by rw [← pullbackSymmetry_hom_comp_snd] infer_instance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
pullback_fst_of_right
null
pullback_to_base [IsOpenImmersion g] : IsOpenImmersion (limit.π (cospan f g) WalkingCospan.one) := by rw [← limit.w (cospan f g) WalkingCospan.Hom.inl] change IsOpenImmersion (_ ≫ f) infer_instance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
pullback_to_base
null
forgetToTop_preserves_of_left : PreservesLimit (cospan f g) Scheme.forgetToTop := by delta Scheme.forgetToTop refine @Limits.comp_preservesLimit _ _ _ _ _ _ (K := cospan f g) _ _ (F := forget) (G := LocallyRingedSpace.forgetToTop) ?_ ?_ · infer_instance refine @preservesLimit_of_iso_diagram _ _ _ _ _ _ _ _ _ (diagramIsoCospan.{u} _).symm ?_ dsimp [LocallyRingedSpace.forgetToTop] infer_instance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
forgetToTop_preserves_of_left
null
forgetToTop_preserves_of_right : PreservesLimit (cospan g f) Scheme.forgetToTop := preservesPullback_symmetry _ _ _
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
forgetToTop_preserves_of_right
null
range_pullback_snd_of_left : Set.range (pullback.snd f g).base = (g ⁻¹ᵁ f.opensRange).1 := by rw [← show _ = (pullback.snd f g).base from PreservesPullback.iso_hom_snd Scheme.forgetToTop f g, TopCat.coe_comp, Set.range_comp, Set.range_eq_univ.mpr, ← @Set.preimage_univ _ _ (pullback.fst f.base g.base)] · erw [TopCat.pullback_snd_image_fst_preimage] rw [Set.image_univ] rfl rw [← TopCat.epi_iff_surjective] infer_instance
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
range_pullback_snd_of_left
null
opensRange_pullback_snd_of_left : (pullback.snd f g).opensRange = g ⁻¹ᵁ f.opensRange := Opens.ext (range_pullback_snd_of_left f g)
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
opensRange_pullback_snd_of_left
null
range_pullback_fst_of_right : Set.range (pullback.fst g f).base = ((Opens.map g.base).obj ⟨Set.range f.base, H.base_open.isOpen_range⟩).1 := by rw [← show _ = (pullback.fst g f).base from PreservesPullback.iso_hom_fst Scheme.forgetToTop g f, TopCat.coe_comp, Set.range_comp, Set.range_eq_univ.mpr, ← @Set.preimage_univ _ _ (pullback.snd g.base f.base)] · erw [TopCat.pullback_fst_image_snd_preimage] rw [Set.image_univ] rfl rw [← TopCat.epi_iff_surjective] infer_instance
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
range_pullback_fst_of_right
null
opensRange_pullback_fst_of_right : (pullback.fst g f).opensRange = g ⁻¹ᵁ f.opensRange := Opens.ext (range_pullback_fst_of_right f g)
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
opensRange_pullback_fst_of_right
null
range_pullback_to_base_of_left : Set.range (pullback.fst f g ≫ f).base = Set.range f.base ∩ Set.range g.base := by rw [pullback.condition, Scheme.comp_base, TopCat.coe_comp, Set.range_comp, range_pullback_snd_of_left, Opens.carrier_eq_coe, Opens.map_obj, Opens.coe_mk, Set.image_preimage_eq_inter_range, Opens.carrier_eq_coe, Scheme.Hom.coe_opensRange]
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
range_pullback_to_base_of_left
null
range_pullback_to_base_of_right : Set.range (pullback.fst g f ≫ g).base = Set.range g.base ∩ Set.range f.base := by rw [Scheme.comp_base, TopCat.coe_comp, Set.range_comp, range_pullback_fst_of_right, Opens.map_obj, Opens.carrier_eq_coe, Opens.coe_mk, Set.image_preimage_eq_inter_range, Set.inter_comm]
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
range_pullback_to_base_of_right
null
image_preimage_eq_preimage_image_of_isPullback {X Y U V : Scheme.{u}} {f : X ⟶ Y} {f' : U ⟶ V} {iU : U ⟶ X} {iV : V ⟶ Y} [IsOpenImmersion iV] [IsOpenImmersion iU] (H : IsPullback f' iU iV f) (W : V.Opens) : iU ''ᵁ f' ⁻¹ᵁ W = f ⁻¹ᵁ iV ''ᵁ W := by ext x by_cases hx : x ∈ Set.range iU.base · obtain ⟨x, rfl⟩ := hx simp only [IsOpenMap.coe_functor_obj, TopologicalSpace.Opens.map_coe, iU.isOpenEmbedding.injective.mem_set_image, Set.mem_preimage, SetLike.mem_coe, ← Scheme.comp_base_apply, ← H.w] simp only [Scheme.comp_coeBase, TopCat.comp_app, iV.isOpenEmbedding.injective.mem_set_image, SetLike.mem_coe] · constructor · rintro ⟨x, hx, rfl⟩; cases hx ⟨x, rfl⟩ · rintro ⟨y, hy, e : iV.base y = f.base x⟩ obtain ⟨x, rfl⟩ := (IsOpenImmersion.range_pullback_snd_of_left iV f).ge ⟨y, e⟩ rw [← H.isoPullback_inv_snd] at hx cases hx ⟨_, rfl⟩
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
image_preimage_eq_preimage_image_of_isPullback
null
lift (H' : Set.range g.base ⊆ Set.range f.base) : Y ⟶ X := ⟨LocallyRingedSpace.IsOpenImmersion.lift f.toLRSHom g.toLRSHom H'⟩ @[reassoc (attr := simp)]
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
lift
The universal property of open immersions: For an open immersion `f : X ⟶ Z`, given any morphism of schemes `g : Y ⟶ Z` whose topological image is contained in the image of `f`, we can lift this morphism to a unique `Y ⟶ X` that commutes with these maps.
lift_fac (H' : Set.range g.base ⊆ Set.range f.base) : lift f g H' ≫ f = g := Scheme.Hom.ext' <| LocallyRingedSpace.IsOpenImmersion.lift_fac f.toLRSHom g.toLRSHom H'
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
lift_fac
null
lift_uniq (H' : Set.range g.base ⊆ Set.range f.base) (l : Y ⟶ X) (hl : l ≫ f = g) : l = lift f g H' := Scheme.Hom.ext' <| LocallyRingedSpace.IsOpenImmersion.lift_uniq f.toLRSHom g.toLRSHom H' l.toLRSHom congr(($hl).toLRSHom) @[reassoc]
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
lift_uniq
null
comp_lift {Y' : Scheme} (g' : Y' ⟶ Y) (H : Set.range g.base ⊆ Set.range f.base) : g' ≫ lift f g H = lift f (g' ≫ g) (.trans (by simp [Set.range_comp_subset_range]) H) := by simp [← cancel_mono f]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
comp_lift
null
isPullback_lift_id {X U Y : Scheme.{u}} (f : X ⟶ Y) (g : U ⟶ Y) [IsOpenImmersion g] (H : Set.range f.base ⊆ Set.range g.base) : IsPullback (IsOpenImmersion.lift g f H) (𝟙 _) g f := by convert IsPullback.of_id_snd.paste_horiz (IsKernelPair.id_of_mono g) · exact (Category.comp_id _).symm · simp
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isPullback_lift_id
null
isoOfRangeEq [IsOpenImmersion g] (e : Set.range f.base = Set.range g.base) : X ≅ Y where hom := lift g f (le_of_eq e) inv := lift f g (le_of_eq e.symm) hom_inv_id := by rw [← cancel_mono f]; simp inv_hom_id := by rw [← cancel_mono g]; simp @[reassoc (attr := simp)]
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isoOfRangeEq
Two open immersions with equal range are isomorphic.
isoOfRangeEq_hom_fac {X Y Z : Scheme.{u}} (f : X ⟶ Z) (g : Y ⟶ Z) [IsOpenImmersion f] [IsOpenImmersion g] (e : Set.range f.base = Set.range g.base) : (isoOfRangeEq f g e).hom ≫ g = f := lift_fac _ _ (le_of_eq e) @[reassoc (attr := simp)]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isoOfRangeEq_hom_fac
null
isoOfRangeEq_inv_fac {X Y Z : Scheme.{u}} (f : X ⟶ Z) (g : Y ⟶ Z) [IsOpenImmersion f] [IsOpenImmersion g] (e : Set.range f.base = Set.range g.base) : (isoOfRangeEq f g e).inv ≫ f = g := lift_fac _ _ (le_of_eq e.symm)
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isoOfRangeEq_inv_fac
null
app_eq_invApp_app_of_comp_eq_aux {X Y U : Scheme.{u}} (f : Y ⟶ U) (g : U ⟶ X) (fg : Y ⟶ X) (H : fg = f ≫ g) [h : IsOpenImmersion g] (V : U.Opens) : f ⁻¹ᵁ V = fg ⁻¹ᵁ (g ''ᵁ V) := by simp_all
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
app_eq_invApp_app_of_comp_eq_aux
null
app_eq_appIso_inv_app_of_comp_eq {X Y U : Scheme.{u}} (f : Y ⟶ U) (g : U ⟶ X) (fg : Y ⟶ X) (H : fg = f ≫ g) [h : IsOpenImmersion g] (V : U.Opens) : f.app V = (g.appIso V).inv ≫ fg.app (g ''ᵁ V) ≫ Y.presheaf.map (eqToHom <| IsOpenImmersion.app_eq_invApp_app_of_comp_eq_aux f g fg H V).op := by subst H rw [Scheme.comp_app, Category.assoc, Scheme.Hom.appIso_inv_app_assoc, f.naturality_assoc, ← Functor.map_comp, ← op_comp, Quiver.Hom.unop_op, eqToHom_map, eqToHom_trans, eqToHom_op, eqToHom_refl, CategoryTheory.Functor.map_id, Category.comp_id]
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
app_eq_appIso_inv_app_of_comp_eq
The `fg` argument is to avoid nasty stuff about dependent types.
lift_app {X Y U : Scheme.{u}} (f : U ⟶ Y) (g : X ⟶ Y) [IsOpenImmersion f] (H) (V : U.Opens) : (IsOpenImmersion.lift f g H).app V = (f.appIso V).inv ≫ g.app (f ''ᵁ V) ≫ X.presheaf.map (eqToHom <| IsOpenImmersion.app_eq_invApp_app_of_comp_eq_aux _ _ _ (IsOpenImmersion.lift_fac f g H).symm V).op := IsOpenImmersion.app_eq_appIso_inv_app_of_comp_eq _ _ _ (lift_fac _ _ _).symm _
theorem
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
lift_app
null
noncomputable ΓIso {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] (U : Y.Opens) : Γ(X, f⁻¹ᵁ U) ≅ Γ(Y, f.opensRange ⊓ U) := (f.appIso (f⁻¹ᵁ U)).symm ≪≫ Y.presheaf.mapIso (eqToIso <| (f.image_preimage_eq_opensRange_inter U).symm).op @[simp]
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
ΓIso
If `f` is an open immersion `X ⟶ Y`, the global sections of `X` are naturally isomorphic to the sections of `Y` over the image of `f`.
ΓIso_inv {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] (U : Y.Opens) : (ΓIso f U).inv = f.appLE (f.opensRange ⊓ U) (f⁻¹ᵁ U) (by rw [← f.image_preimage_eq_opensRange_inter, f.preimage_image_eq]) := by simp only [ΓIso, Iso.trans_inv, Functor.mapIso_inv, Iso.op_inv, eqToIso.inv, eqToHom_op, Iso.symm_inv, Scheme.Hom.appIso_hom', Scheme.Hom.map_appLE] @[reassoc, elementwise]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
ΓIso_inv
null
map_ΓIso_inv {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] (U : Y.Opens) : Y.presheaf.map (homOfLE inf_le_right).op ≫ (ΓIso f U).inv = f.app U := by simp [Scheme.Hom.appLE_eq_app] @[reassoc, elementwise]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
map_ΓIso_inv
null
ΓIso_hom_map {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] (U : Y.Opens) : f.app U ≫ (ΓIso f U).hom = Y.presheaf.map (homOfLE inf_le_right).op := by rw [← map_ΓIso_inv] simp [-ΓIso_inv]
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
ΓIso_hom_map
null
noncomputable ΓIsoTop {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] : Γ(X, ⊤) ≅ Γ(Y, f.opensRange) := (f.appIso ⊤).symm ≪≫ Y.presheaf.mapIso (eqToIso f.image_top_eq_opensRange.symm).op
def
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
ΓIsoTop
Given an open immersion `f : U ⟶ X`, the isomorphism between global sections of `U` and the sections of `X` at the image of `f`.
isIso_of_isOpenImmersion_of_opensRange_eq_top {X Y : Scheme.{u}} (f : X ⟶ Y) [IsOpenImmersion f] (hf : f.opensRange = ⊤) : IsIso f := by rw [isIso_iff_isOpenImmersion] refine ⟨inferInstance, ?_⟩ rw [TopCat.epi_iff_surjective, ← Set.range_eq_univ] exact TopologicalSpace.Opens.ext_iff.mp hf
lemma
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isIso_of_isOpenImmersion_of_opensRange_eq_top
null
isOpenImmersion_isStableUnderComposition : MorphismProperty.IsStableUnderComposition @IsOpenImmersion where comp_mem f g _ _ := LocallyRingedSpace.IsOpenImmersion.comp f.toLRSHom g.toLRSHom
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isOpenImmersion_isStableUnderComposition
null
isOpenImmersion_respectsIso : MorphismProperty.RespectsIso @IsOpenImmersion := by apply MorphismProperty.respectsIso_of_isStableUnderComposition intro _ _ f (hf : IsIso f) have : IsIso f := hf infer_instance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isOpenImmersion_respectsIso
null
isOpenImmersion_isMultiplicative : MorphismProperty.IsMultiplicative @IsOpenImmersion where id_mem _ := inferInstance
instance
AlgebraicGeometry
[ "Mathlib.Geometry.RingedSpace.OpenImmersion", "Mathlib.AlgebraicGeometry.Scheme", "Mathlib.CategoryTheory.Limits.Shapes.Pullback.CommSq", "Mathlib.CategoryTheory.MorphismProperty.Limits" ]
Mathlib/AlgebraicGeometry/OpenImmersion.lean
isOpenImmersion_isMultiplicative
null