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isTerminalPUnit : IsTerminal (CompHaus.of PUnit.{u + 1}) := CompHausLike.isTerminalPUnit
abbrev
Topology
[ "Mathlib.Topology.Category.CompHaus.Basic", "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHaus/Limits.lean
isTerminalPUnit
A one-element space is terminal in `CompHaus`
noncomputable terminalIsoPUnit : ⊤_ CompHaus.{u} ≅ CompHaus.of PUnit := terminalIsTerminal.uniqueUpToIso CompHaus.isTerminalPUnit
def
Topology
[ "Mathlib.Topology.Category.CompHaus.Basic", "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHaus/Limits.lean
terminalIsoPUnit
The isomorphism from an arbitrary terminal object of `CompHaus` to a one-element space.
projective_ultrafilter (X : Type*) : Projective (of <| Ultrafilter X) where factors {Y Z} f g hg := by rw [epi_iff_surjective] at hg obtain ⟨g', hg'⟩ := hg.hasRightInverse let t : X → Y := g' ∘ f ∘ (pure : X → Ultrafilter X) let h : Ultrafilter X → Y := Ultrafilter.extend t have hh : Continuous h := continuous_ultrafilter_extend _ use CompHausLike.ofHom _ ⟨h, hh⟩ apply ConcreteCategory.coe_ext have : g.hom ∘ g' = id := hg'.comp_eq_id convert denseRange_pure.equalizer (g.hom.continuous.comp hh) f.hom.continuous _ rw [comp_assoc, ultrafilter_extend_extends, ← comp_assoc, this, id_comp] rfl
instance
Topology
[ "Mathlib.Topology.Category.CompHaus.Basic", "Mathlib.Topology.Compactification.StoneCech", "Mathlib.CategoryTheory.Preadditive.Projective.Basic", "Mathlib.CategoryTheory.ConcreteCategory.EpiMono" ]
Mathlib/Topology/Category/CompHaus/Projective.lean
projective_ultrafilter
null
projectivePresentation (X : CompHaus) : ProjectivePresentation X where p := of <| Ultrafilter X f := CompHausLike.ofHom _ ⟨_, continuous_ultrafilter_extend id⟩ projective := CompHaus.projective_ultrafilter X epi := ConcreteCategory.epi_of_surjective _ fun x => ⟨(pure x : Ultrafilter X), congr_fun (ultrafilter_extend_extends (𝟙 X)) x⟩
def
Topology
[ "Mathlib.Topology.Category.CompHaus.Basic", "Mathlib.Topology.Compactification.StoneCech", "Mathlib.CategoryTheory.Preadditive.Projective.Basic", "Mathlib.CategoryTheory.ConcreteCategory.EpiMono" ]
Mathlib/Topology/Category/CompHaus/Projective.lean
projectivePresentation
For any compact Hausdorff space `X`, the natural map `Ultrafilter X → X` is a projective presentation.
CompHaus where toTop : TopCat [is_compact : CompactSpace toTop] [is_hausdorff : T2Space toTop] ``` and give it the category structure induced from topological spaces. Then the category of profinite spaces was defined as follows: ```lean
structure
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
CompHaus
null
Profinite where toCompHaus : CompHaus [isTotallyDisconnected : TotallyDisconnectedSpace toCompHaus] ``` The categories `Stonean` consisting of extremally disconnected compact Hausdorff spaces and `LightProfinite` consisting of totally disconnected, second countable compact Hausdorff spaces were defined in a similar way. This resulted in code duplication, and reducing this duplication was part of the motivation for introducing `CompHausLike`. Using `CompHausLike`, we can now define `CompHaus := CompHausLike (fun _ ↦ True)` `Profinite := CompHausLike (fun X ↦ TotallyDisconnectedSpace X)`. `Stonean := CompHausLike (fun X ↦ ExtremallyDisconnected X)`. `LightProfinite := CompHausLike (fun X ↦ TotallyDisconnectedSpace X ∧ SecondCountableTopology X)`. These four categories are important building blocks of condensed objects (see the files `Condensed.Basic` and `Condensed.Light.Basic`). These categories share many properties and often, one wants to argue about several of them simultaneously. This is the other part of the motivation for introducing `CompHausLike`. On paper, one would say "let `C` be on of the categories `CompHaus` or `Profinite`, then the following holds: ...". This was not possible in Lean using the old definitions. Using the new definitions, this becomes a matter of identifying what common property of `CompHaus` and `Profinite` is used in the proof in question, and then proving the theorem for `CompHausLike P` satisfying that property, and it will automatically apply to both `CompHaus` and `Profinite`. -/ universe u open CategoryTheory variable (P : TopCat.{u} → Prop)
structure
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
Profinite
null
CompHausLike where /-- The underlying topological space of an object of `CompHausLike P`. -/ toTop : TopCat /-- The underlying topological space is compact. -/ [is_compact : CompactSpace toTop] /-- The underlying topological space is T2. -/ [is_hausdorff : T2Space toTop] /-- The underlying topological space satisfies P. -/ prop : P toTop
structure
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
CompHausLike
The type of Compact Hausdorff topological spaces satisfying an additional property `P`.
category : Category (CompHausLike P) := InducedCategory.category toTop
instance
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
category
null
concreteCategory : ConcreteCategory (CompHausLike P) (C(·, ·)) := InducedCategory.concreteCategory toTop
instance
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
concreteCategory
null
hasForget₂ : HasForget₂ (CompHausLike P) TopCat := InducedCategory.hasForget₂ _ variable (X : Type u) [TopologicalSpace X] [CompactSpace X] [T2Space X]
instance
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
hasForget₂
null
HasProp : Prop where hasProp : P (TopCat.of X)
class
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
HasProp
This wraps the predicate `P : TopCat → Prop` in a typeclass.
of : CompHausLike P where toTop := TopCat.of X is_compact := ‹_› is_hausdorff := ‹_› prop := HasProp.hasProp
abbrev
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
of
A constructor for objects of the category `CompHausLike P`, taking a type, and bundling the compact Hausdorff topology found by typeclass inference.
coe_of : (CompHausLike.of P X : Type _) = X := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
coe_of
null
coe_id (X : CompHausLike P) : (𝟙 X : X → X) = id := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
coe_id
null
coe_comp {X Y Z : CompHausLike P} (f : X ⟶ Y) (g : Y ⟶ Z) : (f ≫ g : X → Z) = g ∘ f := rfl
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
coe_comp
null
ofHom (f : C(X, Y)) : of P X ⟶ of P Y := ConcreteCategory.ofHom f @[simp] lemma hom_ofHom (f : C(X, Y)) : ConcreteCategory.hom (ofHom P f) = f := rfl @[simp] lemma ofHom_id : ofHom P (ContinuousMap.id X) = 𝟙 (of _ X) := rfl @[simp] lemma ofHom_comp (f : C(X, Y)) (g : C(Y, Z)) : ofHom P (g.comp f) = ofHom _ f ≫ ofHom _ g := rfl
abbrev
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
ofHom
Typecheck a continuous map as a morphism in the category `CompHausLike P`.
@[simps map] toCompHausLike {P P' : TopCat → Prop} (h : ∀ (X : CompHausLike P), P X.toTop → P' X.toTop) : CompHausLike P ⥤ CompHausLike P' where obj X := have : HasProp P' X := ⟨(h _ X.prop)⟩ CompHausLike.of _ X map f := f
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
toCompHausLike
If `P` implies `P'`, then there is a functor from `CompHausLike P` to `CompHausLike P'`.
fullyFaithfulToCompHausLike : (toCompHausLike h).FullyFaithful := fullyFaithfulInducedFunctor _
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
fullyFaithfulToCompHausLike
If `P` implies `P'`, then the functor from `CompHausLike P` to `CompHausLike P'` is fully faithful.
@[simps! map] compHausLikeToTop : CompHausLike.{u} P ⥤ TopCat.{u} := inducedFunctor _
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
compHausLikeToTop
The fully faithful embedding of `CompHausLike P` in `TopCat`.
fullyFaithfulCompHausLikeToTop : (compHausLikeToTop P).FullyFaithful := fullyFaithfulInducedFunctor _
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
fullyFaithfulCompHausLikeToTop
The functor from `CompHausLike P` to `TopCat` is fully faithful.
epi_of_surjective {X Y : CompHausLike.{u} P} (f : X ⟶ Y) (hf : Function.Surjective f) : Epi f := by rw [← CategoryTheory.epi_iff_surjective] at hf exact (forget (CompHausLike P)).epi_of_epi_map hf
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
epi_of_surjective
null
mono_iff_injective {X Y : CompHausLike.{u} P} (f : X ⟶ Y) : Mono f ↔ Function.Injective f := by constructor · intro hf x₁ x₂ h let g₁ : X ⟶ X := ofHom _ ⟨fun _ => x₁, continuous_const⟩ let g₂ : X ⟶ X := ofHom _ ⟨fun _ => x₂, continuous_const⟩ have : g₁ ≫ f = g₂ ≫ f := by ext; exact h exact CategoryTheory.congr_fun ((cancel_mono _).mp this) x₁ · rw [← CategoryTheory.mono_iff_injective] apply (forget (CompHausLike P)).mono_of_mono_map
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
mono_iff_injective
null
isClosedMap {X Y : CompHausLike.{u} P} (f : X ⟶ Y) : IsClosedMap f := fun _ hC => (hC.isCompact.image f.hom.continuous).isClosed
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
isClosedMap
Any continuous function on compact Hausdorff spaces is a closed map.
isIso_of_bijective {X Y : CompHausLike.{u} P} (f : X ⟶ Y) (bij : Function.Bijective f) : IsIso f := by let E := Equiv.ofBijective _ bij have hE : Continuous E.symm := by rw [continuous_iff_isClosed] intro S hS rw [← E.image_eq_preimage] exact isClosedMap f S hS refine ⟨⟨ofHom _ ⟨E.symm, hE⟩, ?_, ?_⟩⟩ · ext x apply E.symm_apply_apply · ext x apply E.apply_symm_apply
theorem
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
isIso_of_bijective
Any continuous bijection of compact Hausdorff spaces is an isomorphism.
forget_reflectsIsomorphisms : (forget (CompHausLike.{u} P)).ReflectsIsomorphisms := ⟨by intro A B f hf; rw [isIso_iff_bijective] at hf; exact isIso_of_bijective _ hf⟩
instance
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
forget_reflectsIsomorphisms
null
noncomputable isoOfBijective {X Y : CompHausLike.{u} P} (f : X ⟶ Y) (bij : Function.Bijective f) : X ≅ Y := letI := isIso_of_bijective _ bij asIso f
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
isoOfBijective
Any continuous bijection of compact Hausdorff spaces induces an isomorphism.
@[simps!] isoOfHomeo {X Y : CompHausLike.{u} P} (f : X ≃ₜ Y) : X ≅ Y := (fullyFaithfulCompHausLikeToTop P).preimageIso (TopCat.isoOfHomeo f)
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
isoOfHomeo
Construct an isomorphism from a homeomorphism.
@[simps!] homeoOfIso {X Y : CompHausLike.{u} P} (f : X ≅ Y) : X ≃ₜ Y := TopCat.homeoOfIso <| (compHausLikeToTop P).mapIso f
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
homeoOfIso
Construct a homeomorphism from an isomorphism.
@[simps] isoEquivHomeo {X Y : CompHausLike.{u} P} : (X ≅ Y) ≃ (X ≃ₜ Y) where toFun := homeoOfIso invFun := isoOfHomeo
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
isoEquivHomeo
The equivalence between isomorphisms in `CompHaus` and homeomorphisms of topological spaces.
const {P : TopCat.{u} → Prop} (T : CompHausLike.{u} P) {S : CompHausLike.{u} P} (s : S) : T ⟶ S := ofHom _ (ContinuousMap.const _ s)
def
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
const
A constant map as a morphism in `CompHausLike`
const_comp {P : TopCat.{u} → Prop} {S T U : CompHausLike.{u} P} (s : S) (g : S ⟶ U) : T.const s ≫ g = T.const (g s) := rfl
lemma
Topology
[ "Mathlib.Topology.Category.TopCat.Basic", "Mathlib.CategoryTheory.Functor.EpiMono", "Mathlib.CategoryTheory.Functor.ReflectsIso.Basic" ]
Mathlib/Topology/Category/CompHausLike/Basic.lean
const_comp
null
noncomputable effectiveEpiStruct {B X : CompHausLike P} (π : X ⟶ B) (hπ : Function.Surjective π) : EffectiveEpiStruct π where desc e h := ofHom _ ((IsQuotientMap.of_surjective_continuous hπ π.hom.continuous).lift e.hom fun a b hab ↦ CategoryTheory.congr_fun (h (ofHom _ ⟨fun _ ↦ a, continuous_const⟩) (ofHom _ ⟨fun _ ↦ b, continuous_const⟩) (by ext; exact hab)) a) fac e h := TopCat.hom_ext ((IsQuotientMap.of_surjective_continuous hπ π.hom.continuous).lift_comp e.hom fun a b hab ↦ CategoryTheory.congr_fun (h (ofHom _ ⟨fun _ ↦ a, continuous_const⟩) (ofHom _ ⟨fun _ ↦ b, continuous_const⟩) (by ext; exact hab)) a) uniq e h g hm := by suffices g = ofHom _ ((IsQuotientMap.of_surjective_continuous hπ π.hom.continuous).liftEquiv ⟨e.hom, fun a b hab ↦ CategoryTheory.congr_fun (h (ofHom _ ⟨fun _ ↦ a, continuous_const⟩) (ofHom _ ⟨fun _ ↦ b, continuous_const⟩) (by ext; exact hab)) a⟩) by assumption apply ConcreteCategory.ext rw [hom_ofHom, ← Equiv.symm_apply_eq (IsQuotientMap.of_surjective_continuous hπ π.hom.continuous).liftEquiv] ext simp only [IsQuotientMap.liftEquiv_symm_apply_coe, ContinuousMap.comp_apply, ← hm] rfl
def
Topology
[ "Mathlib.CategoryTheory.Sites.Coherent.Comparison", "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHausLike/EffectiveEpi.lean
effectiveEpiStruct
If `π` is a surjective morphism in `CompHausLike P`, then it is an effective epi.
preregular [HasExplicitPullbacks P] (hs : ∀ ⦃X Y : CompHausLike P⦄ (f : X ⟶ Y), EffectiveEpi f → Function.Surjective f) : Preregular (CompHausLike P) where exists_fac := by intro X Y Z f π hπ refine ⟨pullback f π, pullback.fst f π, ⟨⟨effectiveEpiStruct _ ?_⟩⟩, pullback.snd f π, (pullback.condition _ _).symm⟩ intro y obtain ⟨z, hz⟩ := hs π hπ (f y) exact ⟨⟨(y, z), hz.symm⟩, rfl⟩
theorem
Topology
[ "Mathlib.CategoryTheory.Sites.Coherent.Comparison", "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHausLike/EffectiveEpi.lean
preregular
null
precoherent [HasExplicitPullbacks P] [HasExplicitFiniteCoproducts.{0} P] (hs : ∀ ⦃X Y : CompHausLike P⦄ (f : X ⟶ Y), EffectiveEpi f → Function.Surjective f) : Precoherent (CompHausLike P) := by have : Preregular (CompHausLike P) := preregular hs infer_instance
theorem
Topology
[ "Mathlib.CategoryTheory.Sites.Coherent.Comparison", "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHausLike/EffectiveEpi.lean
precoherent
null
HasExplicitFiniteCoproduct := HasProp P (Σ (a : α), X a) variable [HasExplicitFiniteCoproduct X]
abbrev
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
HasExplicitFiniteCoproduct
A typeclass describing the property that forming the disjoint union is stable under the property `P`.
finiteCoproduct : CompHausLike P := CompHausLike.of P (Σ (a : α), X a)
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct
The coproduct of a finite family of objects in `CompHaus`, constructed as the disjoint union with its usual topology.
finiteCoproduct.ι (a : α) : X a ⟶ finiteCoproduct X := ofHom _ { toFun := fun x ↦ ⟨a, x⟩ continuous_toFun := continuous_sigmaMk (σ := fun a ↦ X a) }
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.ι
The inclusion of one of the factors into the explicit finite coproduct.
finiteCoproduct.desc {B : CompHausLike P} (e : (a : α) → (X a ⟶ B)) : finiteCoproduct X ⟶ B := ofHom _ { toFun := fun ⟨a, x⟩ ↦ e a x continuous_toFun := by apply continuous_sigma intro a; exact (e a).hom.continuous } @[reassoc (attr := simp)]
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.desc
To construct a morphism from the explicit finite coproduct, it suffices to specify a morphism from each of its factors. This is essentially the universal property of the coproduct.
finiteCoproduct.ι_desc {B : CompHausLike P} (e : (a : α) → (X a ⟶ B)) (a : α) : finiteCoproduct.ι X a ≫ finiteCoproduct.desc X e = e a := rfl
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.ι_desc
null
finiteCoproduct.hom_ext {B : CompHausLike P} (f g : finiteCoproduct X ⟶ B) (h : ∀ a : α, finiteCoproduct.ι X a ≫ f = finiteCoproduct.ι X a ≫ g) : f = g := by ext ⟨a, x⟩ specialize h a apply_fun (fun q ↦ q x) at h exact h
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.hom_ext
null
finiteCoproduct.cofan : Limits.Cofan X := Cofan.mk (finiteCoproduct X) (finiteCoproduct.ι X)
abbrev
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.cofan
The coproduct cocone associated to the explicit finite coproduct.
finiteCoproduct.isColimit : Limits.IsColimit (finiteCoproduct.cofan X) := mkCofanColimit _ (fun s ↦ desc _ fun a ↦ s.inj a) (fun _ _ ↦ ι_desc _ _ _) fun _ _ hm ↦ finiteCoproduct.hom_ext _ _ _ fun a ↦ (ConcreteCategory.hom_ext _ _ fun t ↦ congrFun (congrArg _ (hm a)) t)
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.isColimit
The explicit finite coproduct cocone is a colimit cocone.
finiteCoproduct.ι_injective (a : α) : Function.Injective (finiteCoproduct.ι X a) := by intro x y hxy exact eq_of_heq (Sigma.ext_iff.mp hxy).2
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.ι_injective
null
finiteCoproduct.ι_jointly_surjective (R : finiteCoproduct X) : ∃ (a : α) (r : X a), R = finiteCoproduct.ι X a r := ⟨R.fst, R.snd, rfl⟩
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.ι_jointly_surjective
null
finiteCoproduct.ι_desc_apply {B : CompHausLike P} {π : (a : α) → X a ⟶ B} (a : α) : ∀ x, finiteCoproduct.desc X π (finiteCoproduct.ι X a x) = π a x := by intro x change (ι X a ≫ desc X π) _ = _ simp only [ι_desc]
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.ι_desc_apply
null
HasExplicitFiniteCoproducts : Prop where hasProp {α : Type w} [Finite α] (X : α → CompHausLike.{max u w} P) : HasExplicitFiniteCoproduct X /- This linter complains that the universes `u` and `w` only occur together, but `w` appears by itself in the indexing type of the coproduct. In almost all cases, `w` will be either `0` or `u`, but we want to allow both possibilities. -/ attribute [nolint checkUnivs] HasExplicitFiniteCoproducts attribute [instance] HasExplicitFiniteCoproducts.hasProp
class
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
HasExplicitFiniteCoproducts
A typeclass describing the property that forming all finite disjoint unions is stable under the property `P`.
finiteCoproduct.isOpenEmbedding_ι (a : α) : IsOpenEmbedding (finiteCoproduct.ι X a) := .sigmaMk (σ := fun a ↦ X a)
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
finiteCoproduct.isOpenEmbedding_ι
The inclusion maps into the explicit finite coproduct are open embeddings.
Sigma.isOpenEmbedding_ι (a : α) : IsOpenEmbedding (Sigma.ι X a) := by refine IsOpenEmbedding.of_comp _ (homeoOfIso ((colimit.isColimit _).coconePointUniqueUpToIso (finiteCoproduct.isColimit X))).isOpenEmbedding ?_ convert finiteCoproduct.isOpenEmbedding_ι X a ext x change (Sigma.ι X a ≫ _) x = _ simp
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
Sigma.isOpenEmbedding_ι
The inclusion maps into the abstract finite coproduct are open embeddings.
HasExplicitPullback := HasProp P { xy : X × Y | f xy.fst = g xy.snd } variable [HasExplicitPullback f g] -- (hP : P (TopCat.of { xy : X × Y | f xy.fst = g xy.snd }))
abbrev
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
HasExplicitPullback
The functor to `TopCat` preserves finite coproducts if they exist. -/ instance (P) [HasExplicitFiniteCoproducts.{0} P] : PreservesFiniteCoproducts (compHausLikeToTop P) := by refine ⟨fun _ ↦ ⟨fun {F} ↦ ?_⟩⟩ suffices PreservesColimit (Discrete.functor (F.obj ∘ Discrete.mk)) (compHausLikeToTop P) from preservesColimit_of_iso_diagram _ Discrete.natIsoFunctor.symm apply preservesColimit_of_preserves_colimit_cocone (CompHausLike.finiteCoproduct.isColimit _) exact TopCat.sigmaCofanIsColimit _ /-- The functor to another `CompHausLike` preserves finite coproducts if they exist. -/ noncomputable instance {P' : TopCat.{u} → Prop} (h : ∀ (X : CompHausLike P), P X.toTop → P' X.toTop) : PreservesFiniteCoproducts (toCompHausLike h) := by have : PreservesFiniteCoproducts (toCompHausLike h ⋙ compHausLikeToTop P') := inferInstanceAs (PreservesFiniteCoproducts (compHausLikeToTop _)) exact preservesFiniteCoproducts_of_reflects_of_preserves (toCompHausLike h) (compHausLikeToTop P') end FiniteCoproducts section Pullbacks variable {P : TopCat.{u} → Prop} {X Y B : CompHausLike P} (f : X ⟶ B) (g : Y ⟶ B) /-- A typeclass describing the property that an explicit pullback is stable under the property `P`.
pullback : CompHausLike P := letI set := { xy : X × Y | f xy.fst = g xy.snd } haveI : CompactSpace set := isCompact_iff_compactSpace.mp (isClosed_eq (f.hom.continuous.comp continuous_fst) (g.hom.continuous.comp continuous_snd)).isCompact CompHausLike.of P set
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback
The pullback of two morphisms `f,g` in `CompHaus`, constructed explicitly as the set of pairs `(x,y)` such that `f x = g y`, with the topology induced by the product.
pullback.fst : pullback f g ⟶ X := TopCat.ofHom { toFun := fun ⟨⟨x, _⟩, _⟩ ↦ x continuous_toFun := Continuous.comp continuous_fst continuous_subtype_val }
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.fst
The projection from the pullback to the first component.
pullback.snd : pullback f g ⟶ Y := TopCat.ofHom { toFun := fun ⟨⟨_,y⟩,_⟩ ↦ y continuous_toFun := Continuous.comp continuous_snd continuous_subtype_val } @[reassoc]
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.snd
The projection from the pullback to the second component.
pullback.condition : pullback.fst f g ≫ f = pullback.snd f g ≫ g := by ext ⟨_,h⟩; exact h
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.condition
null
pullback.lift {Z : CompHausLike P} (a : Z ⟶ X) (b : Z ⟶ Y) (w : a ≫ f = b ≫ g) : Z ⟶ pullback f g := TopCat.ofHom { toFun := fun z ↦ ⟨⟨a z, b z⟩, by apply_fun (fun q ↦ q z) at w; exact w⟩ continuous_toFun := by fun_prop } @[reassoc (attr := simp)]
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.lift
Construct a morphism to the explicit pullback given morphisms to the factors which are compatible with the maps to the base. This is essentially the universal property of the pullback.
pullback.lift_fst {Z : CompHausLike P} (a : Z ⟶ X) (b : Z ⟶ Y) (w : a ≫ f = b ≫ g) : pullback.lift f g a b w ≫ pullback.fst f g = a := rfl @[reassoc (attr := simp)]
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.lift_fst
null
pullback.lift_snd {Z : CompHausLike P} (a : Z ⟶ X) (b : Z ⟶ Y) (w : a ≫ f = b ≫ g) : pullback.lift f g a b w ≫ pullback.snd f g = b := rfl
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.lift_snd
null
pullback.hom_ext {Z : CompHausLike P} (a b : Z ⟶ pullback f g) (hfst : a ≫ pullback.fst f g = b ≫ pullback.fst f g) (hsnd : a ≫ pullback.snd f g = b ≫ pullback.snd f g) : a = b := by ext z apply_fun (fun q ↦ q z) at hfst hsnd apply Subtype.ext apply Prod.ext · exact hfst · exact hsnd
lemma
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.hom_ext
null
@[simps! pt π] pullback.cone : Limits.PullbackCone f g := Limits.PullbackCone.mk (pullback.fst f g) (pullback.snd f g) (pullback.condition f g)
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.cone
The pullback cone whose cone point is the explicit pullback.
@[simps! lift] pullback.isLimit : Limits.IsLimit (pullback.cone f g) := Limits.PullbackCone.isLimitAux _ (fun s ↦ pullback.lift f g s.fst s.snd s.condition) (fun _ ↦ pullback.lift_fst _ _ _ _ _) (fun _ ↦ pullback.lift_snd _ _ _ _ _) (fun _ _ hm ↦ pullback.hom_ext _ _ _ _ (hm .left) (hm .right))
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
pullback.isLimit
The explicit pullback cone is a limit cone.
HasExplicitPullbacks : Prop where hasProp {X Y B : CompHausLike P} (f : X ⟶ B) (g : Y ⟶ B) : HasExplicitPullback f g attribute [instance] HasExplicitPullbacks.hasProp
class
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
HasExplicitPullbacks
The functor to `TopCat` creates pullbacks if they exist. -/ noncomputable instance : CreatesLimit (cospan f g) (compHausLikeToTop P) := by refine createsLimitOfFullyFaithfulOfIso (pullback f g) (((TopCat.pullbackConeIsLimit f g).conePointUniqueUpToIso (limit.isLimit _)) ≪≫ Limits.lim.mapIso (?_ ≪≫ (diagramIsoCospan _).symm)) exact Iso.refl _ /-- The functor to `TopCat` preserves pullbacks. -/ noncomputable instance : PreservesLimit (cospan f g) (compHausLikeToTop P) := preservesLimit_of_createsLimit_and_hasLimit _ _ /-- The functor to another `CompHausLike` preserves pullbacks. -/ noncomputable instance {P' : TopCat → Prop} (h : ∀ (X : CompHausLike P), P X.toTop → P' X.toTop) : PreservesLimit (cospan f g) (toCompHausLike h) := by have : PreservesLimit (cospan f g) (toCompHausLike h ⋙ compHausLikeToTop P') := inferInstanceAs (PreservesLimit _ (compHausLikeToTop _)) exact preservesLimit_of_reflects_of_preserves (toCompHausLike h) (compHausLikeToTop P') variable (P) in /-- A typeclass describing the property that forming all explicit pullbacks is stable under the property `P`.
HasExplicitPullbacksOfInclusions [HasExplicitFiniteCoproducts.{0} P] : Prop where hasProp : ∀ {X Y Z : CompHausLike P} (f : Z ⟶ X ⨿ Y), HasExplicitPullback coprod.inl f attribute [instance] HasExplicitPullbacksOfInclusions.hasProp
class
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
HasExplicitPullbacksOfInclusions
A typeclass describing the property that explicit pullbacks along inclusion maps into disjoint unions is stable under the property `P`.
hasPullbacksOfInclusions (hP' : ∀ ⦃X Y B : CompHausLike.{u} P⦄ (f : X ⟶ B) (g : Y ⟶ B) (_ : IsOpenEmbedding f), HasExplicitPullback f g) : HasExplicitPullbacksOfInclusions P := { hasProp := by intro _ _ _ f apply hP' exact Sigma.isOpenEmbedding_ι _ _ }
theorem
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
hasPullbacksOfInclusions
null
isTerminalPUnit [HasProp P PUnit.{u + 1}] : IsTerminal (CompHausLike.of P PUnit.{u + 1}) := haveI : ∀ X, Unique (X ⟶ CompHausLike.of P PUnit.{u + 1}) := fun _ ↦ ⟨⟨ofHom _ ⟨fun _ ↦ PUnit.unit, continuous_const⟩⟩, fun _ ↦ rfl⟩ Limits.IsTerminal.ofUnique _
def
Topology
[ "Mathlib.CategoryTheory.Extensive", "Mathlib.CategoryTheory.Limits.Preserves.Finite", "Mathlib.Topology.Category.CompHausLike.Basic" ]
Mathlib/Topology/Category/CompHausLike/Limits.lean
isTerminalPUnit
The functor to `TopCat` preserves pullbacks of inclusions if they exist. -/ noncomputable instance [HasExplicitPullbacksOfInclusions P] : PreservesPullbacksOfInclusions (compHausLikeToTop P) := { preservesPullbackInl := by intro X Y Z f infer_instance } instance [HasExplicitPullbacksOfInclusions P] : FinitaryExtensive (CompHausLike P) := finitaryExtensive_of_preserves_and_reflects (compHausLikeToTop P) theorem finitaryExtensive (hP' : ∀ ⦃X Y B : CompHausLike.{u} P⦄ (f : X ⟶ B) (g : Y ⟶ B) (_ : IsOpenEmbedding f), HasExplicitPullback f g) : FinitaryExtensive (CompHausLike P) := have := hasPullbacksOfInclusions hP' finitaryExtensive_of_preserves_and_reflects (compHausLikeToTop P) end FiniteCoproducts section Terminal variable {P : TopCat.{u} → Prop} /-- A one-element space is terminal in `CompHaus`
sigmaComparison : X.obj ⟨(of P ((a : α) × σ a))⟩ ⟶ ((a : α) → X.obj ⟨of P (σ a)⟩) := fun x a ↦ X.map (ofHom _ ⟨Sigma.mk a, continuous_sigmaMk⟩).op x
def
Topology
[ "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHausLike/SigmaComparison.lean
sigmaComparison
The comparison map from the value of a condensed set on a finite coproduct to the product of the values on the components.
sigmaComparison_eq_comp_isos : sigmaComparison X σ = (X.mapIso (opCoproductIsoProduct' (finiteCoproduct.isColimit.{u, u} (fun a ↦ of P (σ a))) (productIsProduct fun x ↦ Opposite.op (of P (σ x))))).hom ≫ (PreservesProduct.iso X fun a ↦ ⟨of P (σ a)⟩).hom ≫ (Types.productIso.{u, max u w} fun a ↦ X.obj ⟨of P (σ a)⟩).hom := by ext x a simp only [Cofan.mk_pt, Fan.mk_pt, Functor.mapIso_hom, PreservesProduct.iso_hom, types_comp_apply, Types.productIso_hom_comp_eval_apply] have := congrFun (piComparison_comp_π X (fun a ↦ ⟨of P (σ a)⟩) a) simp only [types_comp_apply] at this rw [this, ← FunctorToTypes.map_comp_apply] simp only [sigmaComparison] apply congrFun congr 2 rw [← opCoproductIsoProduct_inv_comp_ι] simp only [Opposite.unop_op, unop_comp, Quiver.Hom.unop_op, Category.assoc] simp only [opCoproductIsoProduct, ← unop_comp, opCoproductIsoProduct'_comp_self] erw [IsColimit.fac] rfl
theorem
Topology
[ "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHausLike/SigmaComparison.lean
sigmaComparison_eq_comp_isos
null
isIsoSigmaComparison : IsIso <| sigmaComparison X σ := by rw [sigmaComparison_eq_comp_isos] infer_instance
instance
Topology
[ "Mathlib.Topology.Category.CompHausLike.Limits" ]
Mathlib/Topology/Category/CompHausLike/SigmaComparison.lean
isIsoSigmaComparison
null
fintypeDiagram : ℕᵒᵖ ⥤ FintypeCat := S.toLightDiagram.diagram
abbrev
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
fintypeDiagram
The functor `ℕᵒᵖ ⥤ FintypeCat` whose limit is isomorphic to `S`.
diagram : ℕᵒᵖ ⥤ LightProfinite := S.fintypeDiagram ⋙ FintypeCat.toLightProfinite
abbrev
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
diagram
An abbreviation for `S.fintypeDiagram ⋙ FintypeCat.toProfinite`.
asLimitConeAux : Cone S.diagram := let c : Cone (S.diagram ⋙ lightToProfinite) := S.toLightDiagram.cone let hc : IsLimit c := S.toLightDiagram.isLimit liftLimit hc
def
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
asLimitConeAux
A cone over `S.diagram` whose cone point is isomorphic to `S`. (Auxiliary definition, use `S.asLimitCone` instead.)
isoMapCone : lightToProfinite.mapCone S.asLimitConeAux ≅ S.toLightDiagram.cone := let c : Cone (S.diagram ⋙ lightToProfinite) := S.toLightDiagram.cone let hc : IsLimit c := S.toLightDiagram.isLimit liftedLimitMapsToOriginal hc
def
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
isoMapCone
An auxiliary isomorphism of cones used to prove that `S.asLimitConeAux` is a limit cone.
asLimitAux : IsLimit S.asLimitConeAux := let hc : IsLimit (lightToProfinite.mapCone S.asLimitConeAux) := S.toLightDiagram.isLimit.ofIsoLimit S.isoMapCone.symm isLimitOfReflects lightToProfinite hc
def
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
asLimitAux
`S.asLimitConeAux` is indeed a limit cone. (Auxiliary definition, use `S.asLimit` instead.)
asLimitCone : Cone S.diagram where pt := S π := { app := fun n ↦ (lightToProfiniteFullyFaithful.preimageIso <| (Cones.forget _).mapIso S.isoMapCone).inv ≫ S.asLimitConeAux.π.app n naturality := fun _ _ _ ↦ by simp only [Category.assoc, S.asLimitConeAux.w]; rfl }
def
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
asLimitCone
A cone over `S.diagram` whose cone point is `S`.
asLimit : IsLimit S.asLimitCone := S.asLimitAux.ofIsoLimit <| Cones.ext (lightToProfiniteFullyFaithful.preimageIso <| (Cones.forget _).mapIso S.isoMapCone) (fun _ ↦ by rw [← @Iso.inv_comp_eq]; rfl)
def
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
asLimit
`S.asLimitCone` is indeed a limit cone.
lim : Limits.LimitCone S.diagram := ⟨S.asLimitCone, S.asLimit⟩
def
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
lim
A bundled version of `S.asLimitCone` and `S.asLimit`.
proj (n : ℕ) : S ⟶ S.diagram.obj ⟨n⟩ := S.asLimitCone.π.app ⟨n⟩
abbrev
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
proj
The projection from `S` to the `n`th component of `S.diagram`.
lightToProfinite_map_proj_eq (n : ℕ) : lightToProfinite.map (S.proj n) = (lightToProfinite.obj S).asLimitCone.π.app _ := by simp only [Functor.comp_obj, toCompHausLike_map] let c : Cone (S.diagram ⋙ lightToProfinite) := S.toLightDiagram.cone let hc : IsLimit c := S.toLightDiagram.isLimit exact liftedLimitMapsToOriginal_inv_map_π hc _
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
lightToProfinite_map_proj_eq
null
proj_surjective (n : ℕ) : Function.Surjective (S.proj n) := by change Function.Surjective (lightToProfinite.map (S.proj n)) rw [lightToProfinite_map_proj_eq] exact DiscreteQuotient.proj_surjective _
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
proj_surjective
null
component (n : ℕ) : LightProfinite := S.diagram.obj ⟨n⟩
abbrev
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
component
An abbreviation for the `n`th component of `S.diagram`.
transitionMap (n : ℕ) : S.component (n + 1) ⟶ S.component n := S.diagram.map ⟨homOfLE (Nat.le_succ _)⟩
abbrev
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
transitionMap
The transition map from `S_{n+1}` to `S_n` in `S.diagram`.
transitionMapLE {n m : ℕ} (h : n ≤ m) : S.component m ⟶ S.component n := S.diagram.map ⟨homOfLE h⟩
abbrev
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
transitionMapLE
The transition map from `S_m` to `S_n` in `S.diagram`, when `m ≤ n`.
proj_comp_transitionMap (n : ℕ) : S.proj (n + 1) ≫ S.diagram.map ⟨homOfLE (Nat.le_succ _)⟩ = S.proj n := S.asLimitCone.w (homOfLE (Nat.le_succ n)).op
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
proj_comp_transitionMap
null
proj_comp_transitionMap' (n : ℕ) : S.transitionMap n ∘ S.proj (n + 1) = S.proj n := by rw [← S.proj_comp_transitionMap n] rfl
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
proj_comp_transitionMap'
null
proj_comp_transitionMapLE {n m : ℕ} (h : n ≤ m) : S.proj m ≫ S.diagram.map ⟨homOfLE h⟩ = S.proj n := S.asLimitCone.w (homOfLE h).op
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
proj_comp_transitionMapLE
null
proj_comp_transitionMapLE' {n m : ℕ} (h : n ≤ m) : S.transitionMapLE h ∘ S.proj m = S.proj n := by rw [← S.proj_comp_transitionMapLE h] rfl
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
proj_comp_transitionMapLE'
null
surjective_transitionMap (n : ℕ) : Function.Surjective (S.transitionMap n) := by apply Function.Surjective.of_comp (g := S.proj (n + 1)) simpa only [proj_comp_transitionMap'] using S.proj_surjective n
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
surjective_transitionMap
null
surjective_transitionMapLE {n m : ℕ} (h : n ≤ m) : Function.Surjective (S.transitionMapLE h) := by apply Function.Surjective.of_comp (g := S.proj m) simpa only [proj_comp_transitionMapLE'] using S.proj_surjective n
lemma
Topology
[ "Mathlib.Topology.Category.LightProfinite.Basic" ]
Mathlib/Topology/Category/LightProfinite/AsLimit.lean
surjective_transitionMapLE
null
LightProfinite := CompHausLike (fun X ↦ TotallyDisconnectedSpace X ∧ SecondCountableTopology X)
abbrev
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
LightProfinite
`LightProfinite` is the category of second countable profinite spaces.
of (X : Type*) [TopologicalSpace X] [CompactSpace X] [T2Space X] [TotallyDisconnectedSpace X] [SecondCountableTopology X] : LightProfinite := CompHausLike.of _ X
abbrev
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
of
Construct a term of `LightProfinite` from a type endowed with the structure of a compact, Hausdorff, totally disconnected and second countable topological space.
lightToProfinite : LightProfinite ⥤ Profinite := CompHausLike.toCompHausLike (fun _ ↦ inferInstance)
abbrev
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
lightToProfinite
The fully faithful embedding of `LightProfinite` in `Profinite`.
lightToProfiniteFullyFaithful : lightToProfinite.FullyFaithful := fullyFaithfulToCompHausLike _
abbrev
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
lightToProfiniteFullyFaithful
`lightToProfinite` is fully faithful.
lightProfiniteToCompHaus : LightProfinite ⥤ CompHaus := compHausLikeToCompHaus _
abbrev
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
lightProfiniteToCompHaus
The fully faithful embedding of `LightProfinite` in `CompHaus`.
LightProfinite.toTopCat : LightProfinite ⥤ TopCat := CompHausLike.compHausLikeToTop _
abbrev
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
LightProfinite.toTopCat
The fully faithful embedding of `LightProfinite` in `TopCat`. This is definitionally the same as the obvious composite.
@[simps! -isSimp map_hom_apply] FintypeCat.toLightProfinite : FintypeCat ⥤ LightProfinite where obj A := LightProfinite.of A map f := CompHausLike.ofHom _ ⟨f, by continuity⟩
def
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
FintypeCat.toLightProfinite
The natural functor from `Fintype` to `LightProfinite`, endowing a finite type with the discrete topology.
FintypeCat.toLightProfiniteFullyFaithful : toLightProfinite.FullyFaithful where preimage f := (f : _ → _) map_preimage _ := rfl preimage_map _ := rfl
def
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
FintypeCat.toLightProfiniteFullyFaithful
`FintypeCat.toLightProfinite` is fully faithful.
limitCone {J : Type v} [SmallCategory J] [CountableCategory J] (F : J ⥤ LightProfinite.{max u v}) : Limits.Cone F where pt := { toTop := (CompHaus.limitCone.{v, u} (F ⋙ lightProfiniteToCompHaus)).pt.toTop prop := by constructor · infer_instance · change SecondCountableTopology ({ u : ∀ j : J, F.obj j | _ } : Type _) apply IsInducing.subtypeVal.secondCountableTopology } π := { app := (CompHaus.limitCone.{v, u} (F ⋙ lightProfiniteToCompHaus)).π.app naturality := by intro j k f ext ⟨g, p⟩ exact (p f).symm }
def
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
limitCone
An explicit limit cone for a functor `F : J ⥤ LightProfinite`, for a countable category `J` defined in terms of `CompHaus.limitCone`, which is defined in terms of `TopCat.limitCone`.
limitConeIsLimit {J : Type v} [SmallCategory J] [CountableCategory J] (F : J ⥤ LightProfinite.{max u v}) : Limits.IsLimit (limitCone F) where lift S := (CompHaus.limitConeIsLimit.{v, u} (F ⋙ lightProfiniteToCompHaus)).lift (lightProfiniteToCompHaus.mapCone S) uniq S _ h := (CompHaus.limitConeIsLimit.{v, u} _).uniq (lightProfiniteToCompHaus.mapCone S) _ h
def
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
limitConeIsLimit
The limit cone `LightProfinite.limitCone F` is indeed a limit cone.
noncomputable createsCountableLimits {J : Type v} [SmallCategory J] [CountableCategory J] : CreatesLimitsOfShape J lightToProfinite.{max v u} where CreatesLimit {F} := createsLimitOfFullyFaithfulOfIso (limitCone.{v, u} F).pt <| (Profinite.limitConeIsLimit.{v, u} (F ⋙ lightToProfinite)).conePointUniqueUpToIso (limit.isLimit _)
instance
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
createsCountableLimits
null
isClosedMap : IsClosedMap f := CompHausLike.isClosedMap _
theorem
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
isClosedMap
Any morphism of light profinite spaces is a closed map.
isIso_of_bijective (bij : Function.Bijective f) : IsIso f := haveI := CompHausLike.isIso_of_bijective (lightProfiniteToCompHaus.map f) bij isIso_of_fully_faithful lightProfiniteToCompHaus _
theorem
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
isIso_of_bijective
Any continuous bijection of light profinite spaces induces an isomorphism.
noncomputable isoOfBijective (bij : Function.Bijective f) : X ≅ Y := letI := LightProfinite.isIso_of_bijective f bij asIso f
def
Topology
[ "Mathlib.CategoryTheory.Limits.Shapes.Countable", "Mathlib.Topology.Category.Profinite.AsLimit", "Mathlib.Topology.Category.Profinite.CofilteredLimit", "Mathlib.Topology.ClopenBox" ]
Mathlib/Topology/Category/LightProfinite/Basic.lean
isoOfBijective
Any continuous bijection of light profinite spaces induces an isomorphism.