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protected comap_comp (g : C(β, γ)) (f : C(α, β)) : comap (g.comp f) = (comap f).comp (comap g) := rfl
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
comap_comp
null
protected comap_comap (g : C(β, γ)) (f : C(α, β)) (U : Opens γ) : comap f (comap g U) = comap (g.comp f) U := rfl
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
comap_comap
null
comap_injective [T0Space β] : Injective (comap : C(α, β) → FrameHom (Opens β) (Opens α)) := fun f g h => ContinuousMap.ext fun a => Inseparable.eq <| inseparable_iff_forall_isOpen.2 fun s hs => have : comap f ⟨s, hs⟩ = comap g ⟨s, hs⟩ := DFunLike.congr_fun h ⟨_, hs⟩ show a ∈ f ⁻¹' s ↔ a ∈ ...
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
comap_injective
null
@[simps -fullyApplied apply] _root_.Homeomorph.opensCongr (f : α ≃ₜ β) : Opens α ≃o Opens β where toFun := Opens.comap (f.symm : C(β, α)) invFun := Opens.comap (f : C(α, β)) left_inv _ := ext <| f.toEquiv.preimage_symm_preimage _ right_inv _ := ext <| f.toEquiv.symm_preimage_preimage _ map_rel_iff' := by ...
def
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
_root_.Homeomorph.opensCongr
A homeomorphism induces an order-preserving equivalence on open sets, by taking comaps.
_root_.Homeomorph.opensCongr_symm (f : α ≃ₜ β) : f.opensCongr.symm = f.symm.opensCongr := rfl
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
_root_.Homeomorph.opensCongr_symm
null
OpenNhdsOf (x : α) extends Opens α where /-- The point `x` belongs to every `U : TopologicalSpace.OpenNhdsOf x`. -/ mem' : x ∈ carrier
structure
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
OpenNhdsOf
The open neighborhoods of a point. See also `Opens` or `nhds`.
toOpens_injective : Injective (toOpens : OpenNhdsOf x → Opens α) | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
toOpens_injective
null
canLiftSet : CanLift (Set α) (OpenNhdsOf x) (↑) fun s => IsOpen s ∧ x ∈ s := ⟨fun s hs => ⟨⟨⟨s, hs.1⟩, hs.2⟩, rfl⟩⟩
instance
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
canLiftSet
null
protected mem (U : OpenNhdsOf x) : x ∈ U := U.mem'
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
mem
null
protected isOpen (U : OpenNhdsOf x) : IsOpen (U : Set α) := U.is_open'
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
isOpen
null
basis_nhds : (𝓝 x).HasBasis (fun _ : OpenNhdsOf x => True) (↑) := (nhds_basis_opens x).to_hasBasis (fun U hU => ⟨⟨⟨U, hU.2⟩, hU.1⟩, trivial, Subset.rfl⟩) fun U _ => ⟨U, ⟨⟨U.mem, U.isOpen⟩, Subset.rfl⟩⟩
theorem
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
basis_nhds
null
comap (f : C(α, β)) (x : α) : LatticeHom (OpenNhdsOf (f x)) (OpenNhdsOf x) where toFun U := ⟨Opens.comap f U.1, U.mem⟩ map_sup' _ _ := rfl map_inf' _ _ := rfl
def
Topology
[ "Mathlib.Order.Hom.CompleteLattice", "Mathlib.Topology.Compactness.Bases", "Mathlib.Topology.ContinuousMap.Basic", "Mathlib.Order.CompactlyGenerated.Basic", "Mathlib.Order.Copy" ]
Mathlib/Topology/Sets/Opens.lean
comap
Preimage of an open neighborhood of `f x` under a continuous map `f` as a `LatticeHom`.
ClopenUpperSet (α : Type*) [TopologicalSpace α] [LE α] extends Clopens α where upper' : IsUpperSet carrier
structure
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
ClopenUpperSet
The type of clopen upper sets of a topological space.
Simps.coe (s : ClopenUpperSet α) : Set α := s initialize_simps_projections ClopenUpperSet (carrier → coe, as_prefix coe)
def
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
Simps.coe
See Note [custom simps projection].
upper (s : ClopenUpperSet α) : IsUpperSet (s : Set α) := s.upper'
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
upper
null
isClopen (s : ClopenUpperSet α) : IsClopen (s : Set α) := s.isClopen'
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
isClopen
null
@[simps] toUpperSet (s : ClopenUpperSet α) : UpperSet α := ⟨s, s.upper⟩ @[ext]
def
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
toUpperSet
Reinterpret an upper clopen as an upper set.
protected ext {s t : ClopenUpperSet α} (h : (s : Set α) = t) : s = t := SetLike.ext' h @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
ext
null
coe_mk (s : Clopens α) (h) : (mk s h : Set α) = s := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
coe_mk
null
@[simp] coe_sup (s t : ClopenUpperSet α) : (↑(s ⊔ t) : Set α) = ↑s ∪ ↑t := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
coe_sup
null
coe_inf (s t : ClopenUpperSet α) : (↑(s ⊓ t) : Set α) = ↑s ∩ ↑t := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
coe_inf
null
coe_top : (↑(⊤ : ClopenUpperSet α) : Set α) = univ := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
coe_top
null
coe_bot : (↑(⊥ : ClopenUpperSet α) : Set α) = ∅ := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds" ]
Mathlib/Topology/Sets/Order.lean
coe_bot
null
principalOpen (x : X) : Opens X := .mk { y | x ≤ y } <| by rw [IsUpperSet.isOpen_iff_isUpperSet] intro y z h1 h2 exact le_trans h2 h1
def
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
principalOpen
Given `x : X`, this is the principal open subset of `X` generated by `x`.
self_mem_principalOpen (x : X) : x ∈ principalOpen x := le_refl _ @[simp]
lemma
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
self_mem_principalOpen
null
principalOpen_le_iff {x : X} (U : Opens X) : principalOpen x ≤ U ↔ x ∈ U := by refine ⟨fun h => h <| self_mem_principalOpen _, fun hx y hy => ?_⟩ · have := U.isOpen rw [IsUpperSet.isOpen_iff_isUpperSet] at this exact this hy hx
lemma
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
principalOpen_le_iff
null
principalOpen_le {x y : X} (h : x ≤ y) : principalOpen y ≤ principalOpen x := fun _ hc => le_trans h hc variable (X) in
lemma
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
principalOpen_le
null
@[simps] principals : X ⥤ (Opens X)ᵒᵖ where obj x := .op <| principalOpen x map {x y} f := .op <| principalOpen_le f.le |>.hom
def
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
principals
The functor sending `x : X` to the principal open associated with `x`.
exists_le_of_le_sup {ι : Type v} {x : X} (Us : ι → Opens X) (h : principalOpen x ≤ iSup Us) : ∃ i : ι, principalOpen x ≤ Us i := by grind [principalOpen_le_iff, Opens.mem_iSup]
lemma
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
exists_le_of_le_sup
null
principalsKanExtension : (Opens X)ᵒᵖ ⥤ C := (principals X).pointwiseRightKanExtension F
abbrev
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
principalsKanExtension
The right kan extension of `F` along `X ⥤ (Opens X)ᵒᵖ`.
generator (U : Opens X) : StructuredArrow (.op U) (principals X) ⥤ X := StructuredArrow.proj (.op U) (principals X)
abbrev
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
generator
Given a structured arrow `f` with domain `U : Opens X` over `principals X`, this functor sends `f` to its "generator", an element of `X`.
@[simps] projSup {ι : Type v} (Us : ι → Opens X) : StructuredArrow (.op <| iSup Us) (principals X) ⥤ (ObjectProperty.FullSubcategory fun V => ∃ i, V ≤ Us i)ᵒᵖ where obj f := .op <| .mk (principalOpen f.right) <| exists_le_of_le_sup Us f.hom.unop.le map e := .op <| LE.le.hom <| principalOpen_le <| e.right....
def
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
projSup
Given a structured arrow `f` with domain `iSup Us` over `principals X`, where `Us` is a family of `Opens X`, this functor sends `f` to the principal open associated with it, considered as an object in the full subcategory of all `V : Opens X` such that `V ≤ Us i` for some `i`. This definition is primarily meant to be ...
@[simps] lowerCone {α : Type v} (Us : α → Opens X) (S : Cone ((ObjectProperty.ι fun V => ∃ i, V ≤ Us i).op ⋙ principalsKanExtension F)) : Cone (generator (iSup Us) ⋙ F) where pt := S.pt π := { app := fun f => S.π.app ((projSup Us).obj f) ≫ limit.π (generator (principalOpen f.right) ⋙ F) ...
def
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
lowerCone
This is an auxiliary definition which is only meant to be used in `isLimit` below.
isLimit {X : TopCat.{v}} [Preorder X] [Topology.IsUpperSet X] (F : X ⥤ C) (α : Type v) (Us : α → Opens X) : IsLimit (mapCone (principalsKanExtension F) (opensLeCoverCocone Us).op) where lift S := limit.lift _ (lowerCone Us S) fac := by rintro S ⟨V, i, hV⟩ dsimp [forget, opensLeCoverCocone] e...
def
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
isLimit
This is the main construction in this file showing that the right Kan extension of `F : X ⥤ C` along `principals : X ⥤ (Opens X)ᵒᵖ` is a sheaf, by showing that a certain cone is a limit cone. See `isSheaf_principalsKanExtension` for the main application.
isSheaf_principalsKanExtension {X : TopCat.{v}} [Preorder X] [Topology.IsUpperSet X] (F : X ⥤ C) : Presheaf.IsSheaf (principalsKanExtension F) := by rw [isSheaf_iff_isSheafOpensLeCover] intro ι Us constructor apply isLimit
theorem
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
isSheaf_principalsKanExtension
null
Topology.IsUpperSet.isSheaf_of_isRightKanExtension (P : (Opens X)ᵒᵖ ⥤ C) (η : Alexandrov.principals X ⋙ P ⟶ F) [P.IsRightKanExtension η] : Presheaf.IsSheaf (Opens.grothendieckTopology X) P := by let γ : principals X ⋙ principalsKanExtension F ⟶ F := (principals X).pointwiseRightKanExtensionCounit ...
theorem
Topology
[ "Mathlib.Combinatorics.Quiver.ReflQuiver", "Mathlib.Order.CompletePartialOrder", "Mathlib.Topology.Order.UpperLowerSetTopology", "Mathlib.Topology.Sheaves.SheafCondition.OpensLeCover" ]
Mathlib/Topology/Sheaves/Alexandrov.lean
Topology.IsUpperSet.isSheaf_of_isRightKanExtension
The main theorem of this file. If `X` is a topological space and preorder whose topology is the `UpperSet` topology associated with the preorder, `F : X ⥤ C` is a functor into a complete category from the preorder category, and `P : (Opens X)ᵒᵖ ⥤ C` denotes the right Kan extension of `F` along the functor `X ⥤ (Open X)...
restrictOpenCommRingCat_apply {X : TopCat} {F : Presheaf CommRingCat X} {V : Opens ↑X} (f : CommRingCat.carrier (F.obj (op V))) (U : Opens ↑X) (e : U ≤ V := by restrict_tac) : f |_ U = F.map (homOfLE e).op f := rfl
lemma
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
restrictOpenCommRingCat_apply
Unfold `restrictOpen` in the category of commutative rings (with the correct carrier type). Although unification hints help with applying `TopCat.Presheaf.restrictOpenCommRingCat`, so it can be safely de-specialized, this lemma needs to be kept to ensure rewrites go right.
SubmonoidPresheaf (F : X.Presheaf CommRingCat) where /-- The submonoid structure for each component -/ obj : ∀ U, Submonoid (F.obj U) map : ∀ {U V : (Opens X)ᵒᵖ} (i : U ⟶ V), obj U ≤ (obj V).comap (F.map i).hom variable {F : X.Presheaf CommRingCat.{w}} (G : F.SubmonoidPresheaf)
structure
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
SubmonoidPresheaf
A subpresheaf with a submonoid structure on each of the components.
protected noncomputable SubmonoidPresheaf.localizationPresheaf : X.Presheaf CommRingCat where obj U := CommRingCat.of <| Localization (G.obj U) map {_ _} i := CommRingCat.ofHom <| IsLocalization.map _ (F.map i).hom (G.map i) map_id U := by simp_rw [F.map_id] ext x exact IsLocalization.map_id x map_c...
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
SubmonoidPresheaf.localizationPresheaf
The localization of a presheaf of `CommRing`s with respect to a `SubmonoidPresheaf`.
@[simps app] SubmonoidPresheaf.toLocalizationPresheaf : F ⟶ G.localizationPresheaf where app U := CommRingCat.ofHom <| algebraMap (F.obj U) (Localization <| G.obj U) naturality {_ _} i := CommRingCat.hom_ext <| (IsLocalization.map_comp (G.map i)).symm
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
SubmonoidPresheaf.toLocalizationPresheaf
The map into the localization presheaf.
epi_toLocalizationPresheaf : Epi G.toLocalizationPresheaf := @NatTrans.epi_of_epi_app _ _ _ _ _ _ G.toLocalizationPresheaf fun U => Localization.epi' (G.obj U) variable (F)
instance
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
epi_toLocalizationPresheaf
null
@[simps] noncomputable submonoidPresheafOfStalk (S : ∀ x : X, Submonoid (F.stalk x)) : F.SubmonoidPresheaf where obj U := ⨅ x : U.unop, Submonoid.comap (F.germ U.unop x.1 x.2).hom (S x) map {U V} i := by intro s hs simp only [Submonoid.mem_comap, Submonoid.mem_iInf] at hs ⊢ intro x change (F.map...
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
submonoidPresheafOfStalk
Given a submonoid at each of the stalks, we may define a submonoid presheaf consisting of sections whose restriction onto each stalk falls in the given submonoid.
noncomputable totalQuotientPresheaf : X.Presheaf CommRingCat.{w} := (F.submonoidPresheafOfStalk fun x => (F.stalk x)⁰).localizationPresheaf
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
totalQuotientPresheaf
The localization of a presheaf of `CommRing`s at locally non-zero-divisor sections.
noncomputable toTotalQuotientPresheaf : F ⟶ F.totalQuotientPresheaf := SubmonoidPresheaf.toLocalizationPresheaf _ deriving Epi
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
toTotalQuotientPresheaf
The map into the presheaf of total quotient rings
continuousFunctions (X : TopCat.{v}ᵒᵖ) (R : TopCommRingCat.{v}) : CommRingCat.{v} := CommRingCat.of (X.unop ⟶ (forget₂ TopCommRingCat TopCat).obj R)
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
continuousFunctions
The (bundled) commutative ring of continuous functions from a topological space to a topological commutative ring, with pointwise multiplication.
pullback {X Y : TopCatᵒᵖ} (f : X ⟶ Y) (R : TopCommRingCat) : continuousFunctions X R ⟶ continuousFunctions Y R := CommRingCat.ofHom { toFun g := f.unop ≫ g map_one' := rfl map_zero' := rfl map_add' := by cat_disch map_mul' := by cat_disch }
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
pullback
Pulling back functions into a topological ring along a continuous map is a ring homomorphism.
map (X : TopCat.{u}ᵒᵖ) {R S : TopCommRingCat.{u}} (φ : R ⟶ S) : continuousFunctions X R ⟶ continuousFunctions X S := CommRingCat.ofHom { toFun g := g ≫ (forget₂ TopCommRingCat TopCat).map φ map_one' := by ext; exact φ.1.map_one map_zero' := by ext; exact φ.1.map_zero map_add' _ _ := by ext; exact φ.1....
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
map
A homomorphism of topological rings can be postcomposed with functions from a source space `X`; this is a ring homomorphism (with respect to the pointwise ring operations on functions).
commRingYoneda : TopCommRingCat.{u} ⥤ TopCat.{u}ᵒᵖ ⥤ CommRingCat.{u} where obj R := { obj := fun X => continuousFunctions X R map := fun {_ _} f => continuousFunctions.pullback f R map_id := fun X => by ext rfl map_comp := fun {_ _ _} _ _ => rfl } map {_ _} φ := { app := fu...
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
commRingYoneda
An upgraded version of the Yoneda embedding, observing that the continuous maps from `X : TopCat` to `R : TopCommRingCat` form a commutative ring, functorial in both `X` and `R`.
presheafToTopCommRing (T : TopCommRingCat.{v}) : X.Presheaf CommRingCat.{v} := (Opens.toTopCat X).op ⋙ commRingYoneda.obj T
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
presheafToTopCommRing
The presheaf (of commutative rings), consisting of functions on an open set `U ⊆ X` with values in some topological commutative ring `T`. For example, we could construct the presheaf of continuous complex-valued functions of `X` as ``` presheafToTopCommRing X (TopCommRingCat.of ℂ) ``` (this requires `import Topology.I...
algebra_section_stalk (F : X.Presheaf CommRingCat) {U : Opens X} (x : U) : Algebra (F.obj <| op U) (F.stalk x) := (F.germ U x.1 x.2).hom.toAlgebra @[simp]
instance
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
algebra_section_stalk
null
stalk_open_algebraMap {X : TopCat} (F : X.Presheaf CommRingCat) {U : Opens X} (x : U) : algebraMap (F.obj <| op U) (F.stalk x) = (F.germ U x.1 x.2).hom := rfl
theorem
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
stalk_open_algebraMap
null
objSupIsoProdEqLocus {X : TopCat} (F : X.Sheaf CommRingCat) (U V : Opens X) : F.1.obj (op <| U ⊔ V) ≅ CommRingCat.of <| RingHom.eqLocus (RingHom.comp (F.val.map (homOfLE inf_le_left : U ⊓ V ⟶ U).op).hom (RingHom.fst (F.val.obj <| op U) (F.val.obj <| op V))) (RingHom.comp (F.val.map (homOfLE ...
def
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
objSupIsoProdEqLocus
`F(U ⊔ V)` is isomorphic to the `eq_locus` of the two maps `F(U) × F(V) ⟶ F(U ⊓ V)`.
objSupIsoProdEqLocus_hom_fst {X : TopCat} (F : X.Sheaf CommRingCat) (U V : Opens X) (x) : ((F.objSupIsoProdEqLocus U V).hom x).1.fst = F.1.map (homOfLE le_sup_left).op x := ConcreteCategory.congr_hom ((F.isLimitPullbackCone U V).conePointUniqueUpToIso_hom_comp (CommRingCat.pullbackConeIsLimit _ _) Walki...
theorem
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
objSupIsoProdEqLocus_hom_fst
null
objSupIsoProdEqLocus_hom_snd {X : TopCat} (F : X.Sheaf CommRingCat) (U V : Opens X) (x) : ((F.objSupIsoProdEqLocus U V).hom x).1.snd = F.1.map (homOfLE le_sup_right).op x := ConcreteCategory.congr_hom ((F.isLimitPullbackCone U V).conePointUniqueUpToIso_hom_comp (CommRingCat.pullbackConeIsLimit _ _) Walk...
theorem
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
objSupIsoProdEqLocus_hom_snd
null
objSupIsoProdEqLocus_inv_fst {X : TopCat} (F : X.Sheaf CommRingCat) (U V : Opens X) (x) : F.1.map (homOfLE le_sup_left).op ((F.objSupIsoProdEqLocus U V).inv x) = x.1.1 := ConcreteCategory.congr_hom ((F.isLimitPullbackCone U V).conePointUniqueUpToIso_inv_comp (CommRingCat.pullbackConeIsLimit _ _) Walking...
theorem
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
objSupIsoProdEqLocus_inv_fst
null
objSupIsoProdEqLocus_inv_snd {X : TopCat} (F : X.Sheaf CommRingCat) (U V : Opens X) (x) : F.1.map (homOfLE le_sup_right).op ((F.objSupIsoProdEqLocus U V).inv x) = x.1.2 := ConcreteCategory.congr_hom ((F.isLimitPullbackCone U V).conePointUniqueUpToIso_inv_comp (CommRingCat.pullbackConeIsLimit _ _) Walkin...
theorem
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
objSupIsoProdEqLocus_inv_snd
null
objSupIsoProdEqLocus_inv_eq_iff {X : TopCat.{u}} (F : X.Sheaf CommRingCat.{u}) {U V W UW VW : Opens X} (e : W ≤ U ⊔ V) (x) (y : F.1.obj (op W)) (h₁ : UW = U ⊓ W) (h₂ : VW = V ⊓ W) : F.1.map (homOfLE e).op ((F.objSupIsoProdEqLocus U V).inv x) = y ↔ F.1.map (homOfLE (h₁ ▸ inf_le_left : UW ≤ U)).op x.1.1 =...
theorem
Topology
[ "Mathlib.Algebra.Category.Ring.Colimits", "Mathlib.Algebra.Category.Ring.Constructions", "Mathlib.Algebra.Category.Ring.FilteredColimits", "Mathlib.Topology.Category.TopCommRingCat", "Mathlib.Topology.ContinuousMap.Algebra", "Mathlib.Topology.Sheaves.Stalks" ]
Mathlib/Topology/Sheaves/CommRingCat.lean
objSupIsoProdEqLocus_inv_eq_iff
null
@[stacks 0073 "In fact we prove a stronger version with arbitrary target category."] isSheaf_iff_isSheaf_comp' {C : Type u₁} [Category.{v₁} C] {D : Type u₂} [Category.{v₂} D] (G : C ⥤ D) [G.ReflectsIsomorphisms] [HasLimitsOfSize.{v, v} C] [PreservesLimitsOfSize.{v, v} G] {X : TopCat.{v}} (F : Presheaf C X) : Pr...
theorem
Topology
[ "Mathlib.Topology.Sheaves.Sheaf" ]
Mathlib/Topology/Sheaves/Forget.lean
isSheaf_iff_isSheaf_comp'
If `G : C ⥤ D` is a functor which reflects isomorphisms and preserves limits (we assume all limits exist in `C`), then checking the sheaf condition for a presheaf `F : Presheaf C X` is equivalent to checking the sheaf condition for `F ⋙ G`. The important special case is when `C` is a concrete category with a forgetful...
isSheaf_iff_isSheaf_comp {C : Type u₁} [Category.{v} C] {D : Type u₂} [Category.{v} D] (G : C ⥤ D) [G.ReflectsIsomorphisms] [HasLimits C] [PreservesLimits G] {X : TopCat.{v}} (F : Presheaf C X) : Presheaf.IsSheaf F ↔ Presheaf.IsSheaf (F ⋙ G) := isSheaf_iff_isSheaf_comp' G F
theorem
Topology
[ "Mathlib.Topology.Sheaves.Sheaf" ]
Mathlib/Topology/Sheaves/Forget.lean
isSheaf_iff_isSheaf_comp
null
pushforward_sheaf_of_sheaf {F : X.Presheaf C} (h : F.IsSheaf) : (f _* F).IsSheaf := (Opens.map f).op_comp_isSheaf _ _ ⟨_, h⟩ variable (C)
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafCondition.Sites", "Mathlib.CategoryTheory.Sites.Pullback" ]
Mathlib/Topology/Sheaves/Functors.lean
pushforward_sheaf_of_sheaf
The pushforward of a sheaf (by a continuous map) is a sheaf.
pushforward (f : X ⟶ Y) : X.Sheaf C ⥤ Y.Sheaf C := (Opens.map f).sheafPushforwardContinuous _ _ _
def
Topology
[ "Mathlib.Topology.Sheaves.SheafCondition.Sites", "Mathlib.CategoryTheory.Sites.Pullback" ]
Mathlib/Topology/Sheaves/Functors.lean
pushforward
The pushforward functor.
pushforward_forget (f : X ⟶ Y) : pushforward C f ⋙ forget C Y = forget C X ⋙ Presheaf.pushforward C f := rfl
lemma
Topology
[ "Mathlib.Topology.Sheaves.SheafCondition.Sites", "Mathlib.CategoryTheory.Sites.Pullback" ]
Mathlib/Topology/Sheaves/Functors.lean
pushforward_forget
null
pushforwardForgetIso (f : X ⟶ Y) : pushforward C f ⋙ forget C Y ≅ forget C X ⋙ Presheaf.pushforward C f := Iso.refl _ variable {C} @[simp] lemma pushforward_obj_val (f : X ⟶ Y) (F : X.Sheaf C) : ((pushforward C f).obj F).1 = f _* F.1 := rfl @[simp] lemma pushforward_map (f : X ⟶ Y) {F F' : X.Sheaf C} (α : F ⟶ F...
def
Topology
[ "Mathlib.Topology.Sheaves.SheafCondition.Sites", "Mathlib.CategoryTheory.Sites.Pullback" ]
Mathlib/Topology/Sheaves/Functors.lean
pushforwardForgetIso
Pushforward of sheaves is isomorphic (actually definitionally equal) to pushforward of presheaves.
pullback (f : X ⟶ Y) : Y.Sheaf A ⥤ X.Sheaf A := (Opens.map f).sheafPullback _ _ _
def
Topology
[ "Mathlib.Topology.Sheaves.SheafCondition.Sites", "Mathlib.CategoryTheory.Sites.Pullback" ]
Mathlib/Topology/Sheaves/Functors.lean
pullback
The pullback functor.
pullbackIso (f : X ⟶ Y) : pullback A f ≅ forget A Y ⋙ Presheaf.pullback A f ⋙ presheafToSheaf _ _ := Functor.sheafPullbackConstruction.sheafPullbackIso _ _ _ _
def
Topology
[ "Mathlib.Topology.Sheaves.SheafCondition.Sites", "Mathlib.CategoryTheory.Sites.Pullback" ]
Mathlib/Topology/Sheaves/Functors.lean
pullbackIso
The pullback of a sheaf is isomorphic (actually definitionally equal) to the sheafification of the pullback as a presheaf.
pullbackPushforwardAdjunction (f : X ⟶ Y) : pullback A f ⊣ pushforward A f := (Opens.map f).sheafAdjunctionContinuous _ _ _
def
Topology
[ "Mathlib.Topology.Sheaves.SheafCondition.Sites", "Mathlib.CategoryTheory.Sites.Pullback" ]
Mathlib/Topology/Sheaves/Functors.lean
pullbackPushforwardAdjunction
The adjunction between pullback and pushforward for sheaves on topological spaces.
isSheaf_of_isLimit [HasLimitsOfShape J C] {X : TopCat} (F : J ⥤ Presheaf.{v} C X) (H : ∀ j, (F.obj j).IsSheaf) {c : Cone F} (hc : IsLimit c) : c.pt.IsSheaf := by let F' : J ⥤ Sheaf C X := { obj := fun j => ⟨F.obj j, H j⟩ map := fun f => ⟨F.map f⟩ } let e : F' ⋙ Sheaf.forget C X ≅ F := NatIso.ofCompone...
theorem
Topology
[ "Mathlib.Topology.Sheaves.Sheaf", "Mathlib.CategoryTheory.Sites.Limits", "Mathlib.CategoryTheory.Limits.FunctorCategory.Basic" ]
Mathlib/Topology/Sheaves/Limits.lean
isSheaf_of_isLimit
null
limit_isSheaf [HasLimitsOfShape J C] {X : TopCat} (F : J ⥤ Presheaf.{v} C X) (H : ∀ j, (F.obj j).IsSheaf) : (limit F).IsSheaf := isSheaf_of_isLimit F H (limit.isLimit F)
theorem
Topology
[ "Mathlib.Topology.Sheaves.Sheaf", "Mathlib.CategoryTheory.Sites.Limits", "Mathlib.CategoryTheory.Limits.FunctorCategory.Basic" ]
Mathlib/Topology/Sheaves/Limits.lean
limit_isSheaf
null
IsLocallySurjective (T : ℱ ⟶ 𝒢) := CategoryTheory.Presheaf.IsLocallySurjective (Opens.grothendieckTopology X) T
def
Topology
[ "Mathlib.Topology.Sheaves.Presheaf", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.CategoryTheory.Limits.Preserves.Filtered", "Mathlib.CategoryTheory.Sites.LocallySurjective" ]
Mathlib/Topology/Sheaves/LocallySurjective.lean
IsLocallySurjective
A map of presheaves `T : ℱ ⟶ 𝒢` is **locally surjective** if for any open set `U`, section `t` over `U`, and `x ∈ U`, there exists an open set `x ∈ V ⊆ U` and a section `s` over `V` such that `$T_*(s_V) = t|_V$`. See `TopCat.Presheaf.isLocallySurjective_iff` below.
isLocallySurjective_iff (T : ℱ ⟶ 𝒢) : IsLocallySurjective T ↔ ∀ (U t), ∀ x ∈ U, ∃ (V : _) (ι : V ⟶ U), (∃ s, (T.app _) s = t |_ₕ ι) ∧ x ∈ V := ⟨fun h _ => h.imageSieve_mem, fun h => ⟨h _⟩⟩
theorem
Topology
[ "Mathlib.Topology.Sheaves.Presheaf", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.CategoryTheory.Limits.Preserves.Filtered", "Mathlib.CategoryTheory.Sites.LocallySurjective" ]
Mathlib/Topology/Sheaves/LocallySurjective.lean
isLocallySurjective_iff
null
locally_surjective_iff_surjective_on_stalks (T : ℱ ⟶ 𝒢) : IsLocallySurjective T ↔ ∀ x : X, Function.Surjective ((stalkFunctor C x).map T) := by constructor <;> intro hT · /- human proof: Let g ∈ Γₛₜ 𝒢 x be a germ. Represent it on an open set U ⊆ X as ⟨t, U⟩. By local surjectivity, pass to a sm...
theorem
Topology
[ "Mathlib.Topology.Sheaves.Presheaf", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.CategoryTheory.Limits.Preserves.Filtered", "Mathlib.CategoryTheory.Sites.LocallySurjective" ]
Mathlib/Topology/Sheaves/LocallySurjective.lean
locally_surjective_iff_surjective_on_stalks
An equivalent condition for a map of presheaves to be locally surjective is for all the induced maps on stalks to be surjective.
PrelocalPredicate where /-- The underlying predicate of a prelocal predicate -/ pred : ∀ {U : Opens X}, (∀ x : U, T x) → Prop /-- The underlying predicate should be invariant under restriction -/ res : ∀ {U V : Opens X} (i : U ⟶ V) (f : ∀ x : V, T x) (_ : pred f), pred fun x : U ↦ f (i x) variable (X)
structure
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
PrelocalPredicate
Given a topological space `X : TopCat` and a type family `T : X → Type`, a `P : PrelocalPredicate T` consists of: * a family of predicates `P.pred`, one for each `U : Opens X`, of the form `(Π x : U, T x) → Prop` * a proof that if `f : Π x : V, T x` satisfies the predicate on `V : Opens X`, then the restriction of `f...
@[simps!] continuousPrelocal (T) [TopologicalSpace T] : PrelocalPredicate fun _ : X ↦ T where pred {_} f := Continuous f res {_ _} i _ h := Continuous.comp h (Opens.isOpenEmbedding_of_le i.le).continuous
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
continuousPrelocal
Continuity is a "prelocal" predicate on functions to a fixed topological space `T`.
inhabitedPrelocalPredicate (T) [TopologicalSpace T] : Inhabited (PrelocalPredicate fun _ : X ↦ T) := ⟨continuousPrelocal X T⟩ variable {X} in
instance
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
inhabitedPrelocalPredicate
Satisfying the inhabited linter.
LocalPredicate extends PrelocalPredicate T where /-- A local predicate must be local --- provided that it is locally satisfied, it is also globally satisfied -/ locality : ∀ {U : Opens X} (f : ∀ x : U, T x) (_ : ∀ x : U, ∃ (V : Opens X) (_ : x.1 ∈ V) (i : V ⟶ U), pred fun x : V ↦ f (i x : U)), p...
structure
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
LocalPredicate
Given a topological space `X : TopCat` and a type family `T : X → Type`, a `P : LocalPredicate T` consists of: * a family of predicates `P.pred`, one for each `U : Opens X`, of the form `(Π x : U, T x) → Prop` * a proof that if `f : Π x : V, T x` satisfies the predicate on `V : Opens X`, then the restriction of `f` t...
continuousLocal (T) [TopologicalSpace T] : LocalPredicate fun _ : X ↦ T := { continuousPrelocal X T with locality := fun {U} f w ↦ by apply continuous_iff_continuousAt.2 intro x specialize w x rcases w with ⟨V, m, i, w⟩ dsimp at w rw [continuous_iff_continuousAt] at w spe...
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
continuousLocal
Continuity is a "local" predicate on functions to a fixed topological space `T`.
inhabitedLocalPredicate (T) [TopologicalSpace T] : Inhabited (LocalPredicate fun _ : X ↦ T) := ⟨continuousLocal X T⟩ variable {X T}
instance
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
inhabitedLocalPredicate
Satisfying the inhabited linter.
PrelocalPredicate.and (P Q : PrelocalPredicate T) : PrelocalPredicate T where pred f := P.pred f ∧ Q.pred f res i f h := ⟨P.res i f h.1, Q.res i f h.2⟩
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
PrelocalPredicate.and
The conjunction of two prelocal predicates is prelocal.
LocalPredicate.and (P Q : LocalPredicate T) : LocalPredicate T where __ := P.1.and Q.1 locality f w := by refine ⟨P.locality f ?_, Q.locality f ?_⟩ <;> (intro x; have ⟨V, hV, i, h⟩ := w x; use V, hV, i) exacts [h.1, h.2]
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
LocalPredicate.and
The conjunction of two prelocal predicates is prelocal.
isSection {T} (p : T → X) : LocalPredicate fun _ : X ↦ T where pred f := p ∘ f = (↑) res _ _ h := funext fun _ ↦ congr_fun h _ locality _ w := funext fun x ↦ have ⟨_, hV, _, h⟩ := w x; congr_fun h ⟨x, hV⟩
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
isSection
The local predicate of being a partial section of a function.
PrelocalPredicate.sheafify {T : X → Type*} (P : PrelocalPredicate T) : LocalPredicate T where pred {U} f := ∀ x : U, ∃ (V : Opens X) (_ : x.1 ∈ V) (i : V ⟶ U), P.pred fun x : V ↦ f (i x : U) res {V U} i f w x := by specialize w (i x) rcases w with ⟨V', m', i', p⟩ exact ⟨V ⊓ V', ⟨x.2, m'⟩, V.infLELeft _,...
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
PrelocalPredicate.sheafify
Given a `P : PrelocalPredicate`, we can always construct a `LocalPredicate` by asking that the condition from `P` holds locally near every point.
sheafifyOf {T : X → Type*} {P : PrelocalPredicate T} {U : Opens X} {f : ∀ x : U, T x} (h : P.pred f) : P.sheafify.pred f := fun x ↦ ⟨U, x.2, 𝟙 _, by convert h⟩
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
sheafifyOf
null
sheafify_inductionOn {X : TopCat} {T : X → Type*} (P : PrelocalPredicate T) (op : {x : X} → T x → T x) (hop : ∀ {U : Opens X} {a : (x : U) → T x}, P.pred a → ∀ (p : U), ∃ (W : Opens X) (i : W ⟶ U), p.1 ∈ W ∧ P.pred fun x : W ↦ op (a (i x))) {U : Opens X} {a : (x : U) → T x} (ha : P.sheafify.pred a) : ...
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
sheafify_inductionOn
For a unary operation (e.g. `x ↦ -x`) defined at each stalk, if a prelocal predicate is closed under the operation on each open set (possibly by refinement), then the sheafified predicate is also closed under the operation. See `sheafify_inductionOn'` for the version without refinement.
sheafify_inductionOn' {X : TopCat} {T : X → Type*} (P : PrelocalPredicate T) (op : {x : X} → T x → T x) (hop : ∀ {U : Opens X} {a : (x : U) → T x}, P.pred a → P.pred fun x : U ↦ op (a x)) {U : Opens X} {a : (x : U) → T x} (ha : P.sheafify.pred a) : P.sheafify.pred (fun x : U ↦ op (a x)) := P.sheafify_...
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
sheafify_inductionOn'
For a unary operation (e.g. `x ↦ -x`) defined at each stalk, if a prelocal predicate is closed under the operation on each open set, then the sheafified predicate is also closed under the operation. See `sheafify_inductionOn` for the version with refinement.
sheafify_inductionOn₂ {X : TopCat} {T₁ T₂ T₃ : X → Type*} (P₁ : PrelocalPredicate T₁) (P₂ : PrelocalPredicate T₂) (P₃ : PrelocalPredicate T₃) (op : {x : X} → T₁ x → T₂ x → T₃ x) (hop : ∀ {U V : Opens X} {a : (x : U) → T₁ x} {b : (x : V) → T₂ x}, P₁.pred a → P₂.pred b → ∀ (p : (U ⊓ V : Opens X)), ∃ (W ...
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
sheafify_inductionOn₂
For a binary operation (e.g. `x ↦ y ↦ x + y`) defined at each stalk, if a prelocal predicate is closed under the operation on each open set (possibly by refinement), then the sheafified predicate is also closed under the operation. See `sheafify_inductionOn₂'` for the version without refinement.
sheafify_inductionOn₂' {X : TopCat} {T₁ T₂ T₃ : X → Type*} (P₁ : PrelocalPredicate T₁) (P₂ : PrelocalPredicate T₂) (P₃ : PrelocalPredicate T₃) (op : {x : X} → T₁ x → T₂ x → T₃ x) (hop : ∀ {U V : Opens X} {a : (x : U) → T₁ x} {b : (x : V) → T₂ x}, P₁.pred a → P₂.pred b → P₃.pred fun x : (U ⊓ V : Opens ...
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
sheafify_inductionOn₂'
For a binary operation (e.g. `x ↦ y ↦ x + y`) defined at each stalk, if a prelocal predicate is closed under the operation on each open set, then the sheafified predicate is also closed under the operation. See `sheafify_inductionOn₂` for the version with refinement.
@[simps!] subpresheafToTypes (P : PrelocalPredicate T) : Presheaf (Type _) X where obj U := { f : ∀ x : U.unop, T x // P.pred f } map {_ _} i f := ⟨fun x ↦ f.1 (i.unop x), P.res i.unop f.1 f.2⟩
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
subpresheafToTypes
The subpresheaf of dependent functions on `X` satisfying the "pre-local" predicate `P`.
subtype : subpresheafToTypes P ⟶ presheafToTypes X T where app _ f := f.1 open TopCat.Presheaf attribute [local instance] Types.instFunLike Types.instConcreteCategory in
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
subtype
The natural transformation including the subpresheaf of functions satisfying a local predicate into the presheaf of all functions.
isSheaf (P : LocalPredicate T) : (subpresheafToTypes P.toPrelocalPredicate).IsSheaf := Presheaf.isSheaf_of_isSheafUniqueGluing_types _ fun ι U sf sf_comp ↦ by let sf' (i : ι) : (presheafToTypes X T).obj (op (U i)) := (sf i).val have sf'_comp : (presheafToTypes X T).IsCompatible U sf' := fun i j ↦ congr_...
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
isSheaf
The functions satisfying a local predicate satisfy the sheaf condition.
@[simps] subsheafToTypes (P : LocalPredicate T) : Sheaf (Type _) X := ⟨subpresheafToTypes P.toPrelocalPredicate, subpresheafToTypes.isSheaf P⟩
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
subsheafToTypes
The subsheaf of the sheaf of all dependently typed functions satisfying the local predicate `P`.
stalkToFiber (P : LocalPredicate T) (x : X) : (subsheafToTypes P).presheaf.stalk x ⟶ T x := by refine colimit.desc _ { pt := T x ι := { app := fun U f ↦ ?_ naturality := ?_ } } · exact f.1 ⟨x, (unop U).2⟩ · aesop
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
stalkToFiber
There is a canonical map from the stalk to the original fiber, given by evaluating sections.
stalkToFiber_germ (P : LocalPredicate T) (U : Opens X) (x : X) (hx : x ∈ U) (f) : stalkToFiber P x ((subsheafToTypes P).presheaf.germ U x hx f) = f.1 ⟨x, hx⟩ := by simp [Presheaf.germ, stalkToFiber]
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
stalkToFiber_germ
null
stalkToFiber_surjective (P : LocalPredicate T) (x : X) (w : ∀ t : T x, ∃ (U : OpenNhds x) (f : ∀ y : U.1, T y) (_ : P.pred f), f ⟨x, U.2⟩ = t) : Function.Surjective (stalkToFiber P x) := fun t ↦ by rcases w t with ⟨U, f, h, rfl⟩ fconstructor · exact (subsheafToTypes P).presheaf.germ _ x U.2 ⟨f, h⟩ · exa...
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
stalkToFiber_surjective
The `stalkToFiber` map is surjective at `x` if every point in the fiber `T x` has an allowed section passing through it.
stalkToFiber_injective (P : LocalPredicate T) (x : X) (w : ∀ (U V : OpenNhds x) (fU : ∀ y : U.1, T y) (_ : P.pred fU) (fV : ∀ y : V.1, T y) (_ : P.pred fV) (_ : fU ⟨x, U.2⟩ = fV ⟨x, V.2⟩), ∃ (W : OpenNhds x) (iU : W ⟶ U) (iV : W ⟶ V), ∀ w : W.1, fU (iU w : U.1) = fV (iV w : V.1)) : ...
theorem
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
stalkToFiber_injective
The `stalkToFiber` map is injective at `x` if any two allowed sections which agree at `x` agree on some neighborhood of `x`.
subpresheafContinuousPrelocalIsoPresheafToTop {X : TopCat.{u}} (T : TopCat.{u}) : subpresheafToTypes (continuousPrelocal X T) ≅ presheafToTop X T := NatIso.ofComponents fun X ↦ { hom := by rintro ⟨f, c⟩; exact ofHom ⟨f, c⟩ inv := by rintro ⟨f, c⟩; exact ⟨f, c⟩ }
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
subpresheafContinuousPrelocalIsoPresheafToTop
Some repackaging: the presheaf of functions satisfying `continuousPrelocal` is just the same thing as the presheaf of continuous functions.
sheafToTop (T : TopCat) : Sheaf (Type _) X := ⟨presheafToTop X T, Presheaf.isSheaf_of_iso (subpresheafContinuousPrelocalIsoPresheafToTop T) (subpresheafToTypes.isSheaf (continuousLocal X T))⟩
def
Topology
[ "Mathlib.Topology.Sheaves.SheafOfFunctions", "Mathlib.Topology.Sheaves.Stalks", "Mathlib.Topology.Sheaves.SheafCondition.UniqueGluing" ]
Mathlib/Topology/Sheaves/LocalPredicate.lean
sheafToTop
The sheaf of continuous functions on `X` with values in a space `T`.
@[simps! toSquare] noncomputable mayerVietorisSquare' (sq : Square (Opens T)) (h₄ : sq.X₄ = sq.X₂ ⊔ sq.X₃) (h₁ : sq.X₁ = sq.X₂ ⊓ sq.X₃) : (Opens.grothendieckTopology T).MayerVietorisSquare := GrothendieckTopology.MayerVietorisSquare.mk_of_isPullback (J := (Opens.grothendieckTopology T)) sq (Square.IsP...
def
Topology
[ "Mathlib.CategoryTheory.Sites.MayerVietorisSquare", "Mathlib.CategoryTheory.Sites.Spaces", "Mathlib.CategoryTheory.Functor.ReflectsIso.Balanced" ]
Mathlib/Topology/Sheaves/MayerVietoris.lean
mayerVietorisSquare'
A square consisting of opens `X₂ ⊓ X₃`, `X₂`, `X₃` and `X₂ ⊔ X₃` is a Mayer-Vietoris square.
@[simps!] noncomputable mayerVietorisSquare (U V : Opens T) : (Opens.grothendieckTopology T).MayerVietorisSquare := mayerVietorisSquare' { X₁ := U ⊓ V X₂ := U X₃ := V X₄ := U ⊔ V f₁₂ := homOfLE inf_le_left f₁₃ := homOfLE inf_le_right f₂₄ := homOfLE le_sup_left f₃₄ := ...
def
Topology
[ "Mathlib.CategoryTheory.Sites.MayerVietorisSquare", "Mathlib.CategoryTheory.Sites.Spaces", "Mathlib.CategoryTheory.Functor.ReflectsIso.Balanced" ]
Mathlib/Topology/Sheaves/MayerVietoris.lean
mayerVietorisSquare
The Mayer-Vietoris square attached to two open subsets of a topological space.
Presheaf (X : TopCat.{w}) : Type max u v w := (Opens X)ᵒᵖ ⥤ C
def
Topology
[ "Mathlib.Topology.Category.TopCat.Opens", "Mathlib.CategoryTheory.Adjunction.Unique", "Mathlib.CategoryTheory.Functor.KanExtension.Adjunction", "Mathlib.Topology.Sheaves.Init", "Mathlib.Data.Set.Subsingleton" ]
Mathlib/Topology/Sheaves/Presheaf.lean
Presheaf
The category of `C`-valued presheaves on a (bundled) topological space `X`.
@[simp] comp_app {X : TopCat} {U : (Opens X)ᵒᵖ} {P Q R : Presheaf C X} (f : P ⟶ Q) (g : Q ⟶ R) : (f ≫ g).app U = f.app U ≫ g.app U := rfl @[ext]
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Opens", "Mathlib.CategoryTheory.Adjunction.Unique", "Mathlib.CategoryTheory.Functor.KanExtension.Adjunction", "Mathlib.Topology.Sheaves.Init", "Mathlib.Data.Set.Subsingleton" ]
Mathlib/Topology/Sheaves/Presheaf.lean
comp_app
null