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UniformFun.ofFun_prod {β : Type*} [CommMonoid β] {f : ι → α → β} (I : Finset ι) : ofFun (∏ i ∈ I, f i) = ∏ i ∈ I, ofFun (f i) := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.ofFun_prod
null
UniformFun.toFun_prod {β : Type*} [CommMonoid β] {f : ι → α → β} (I : Finset ι) : toFun (∏ i ∈ I, f i) = ∏ i ∈ I, toFun (f i) := rfl
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.toFun_prod
null
UniformFun.uniformContinuousConstSMul : UniformContinuousConstSMul M (α →ᵤ X) where uniformContinuous_const_smul c := UniformFun.postcomp_uniformContinuous <| uniformContinuous_const_smul c
instance
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.uniformContinuousConstSMul
null
UniformFunOn.uniformContinuousConstSMul {𝔖 : Set (Set α)} : UniformContinuousConstSMul M (α →ᵤ[𝔖] X) where uniformContinuous_const_smul c := UniformOnFun.postcomp_uniformContinuous <| uniformContinuous_const_smul c
instance
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFunOn.uniformContinuousConstSMul
null
CompletableTopField : Prop extends T0Space K where nice : ∀ F : Filter K, Cauchy F → 𝓝 0 ⊓ F = ⊥ → Cauchy (map (fun x => x⁻¹) F)
class
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
CompletableTopField
A topological field is completable if it is separated and the image under the mapping x ↦ x⁻¹ of every Cauchy filter (with respect to the additive uniform structure) which does not have a cluster point at 0 is a Cauchy filter (with respect to the additive uniform structure). This ensures the completion is a field.
hatInv : hat K → hat K := isDenseInducing_coe.extend fun x : K => (↑x⁻¹ : hat K) @[fun_prop]
def
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
hatInv
extension of inversion to the completion of a field.
continuous_hatInv [CompletableTopField K] {x : hat K} (h : x ≠ 0) : ContinuousAt hatInv x := by refine isDenseInducing_coe.continuousAt_extend ?_ apply mem_of_superset (compl_singleton_mem_nhds h) intro y y_ne rw [mem_compl_singleton_iff] at y_ne apply CompleteSpace.complete have : (fun (x : K) => (↑x⁻¹ : hat K)) = ((fun (y : K) => (↑y : hat K))∘(fun (x : K) => (x⁻¹ : K))) := by unfold Function.comp simp rw [this, ← Filter.map_map] apply Cauchy.map _ (Completion.uniformContinuous_coe K) apply CompletableTopField.nice · haveI := isDenseInducing_coe.comap_nhds_neBot y apply cauchy_nhds.comap rw [Completion.comap_coe_eq_uniformity] · have eq_bot : 𝓝 (0 : hat K) ⊓ 𝓝 y = ⊥ := by by_contra h exact y_ne (eq_of_nhds_neBot <| neBot_iff.mpr h).symm rw [isDenseInducing_coe.nhds_eq_comap (0 : K), ← Filter.comap_inf] norm_cast rw [eq_bot] exact comap_bot open Classical in
theorem
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
continuous_hatInv
null
instInvCompletion : Inv (hat K) := ⟨fun x => if x = 0 then 0 else hatInv x⟩ variable [IsTopologicalDivisionRing K]
instance
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
instInvCompletion
The value of `hat_inv` at zero is not really specified, although it's probably zero. Here we explicitly enforce the `inv_zero` axiom.
hatInv_extends {x : K} (h : x ≠ 0) : hatInv (x : hat K) = ↑(x⁻¹ : K) := isDenseInducing_coe.extend_eq_at ((continuous_coe K).continuousAt.comp (continuousAt_inv₀ h)) variable [CompletableTopField K] @[norm_cast]
theorem
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
hatInv_extends
null
coe_inv (x : K) : (x : hat K)⁻¹ = ((x⁻¹ : K) : hat K) := by by_cases h : x = 0 · rw [h, inv_zero] dsimp [Inv.inv] norm_cast simp · conv_lhs => dsimp [Inv.inv] rw [if_neg] · exact hatInv_extends h · exact fun H => h (isDenseEmbedding_coe.injective H) variable [IsUniformAddGroup K]
theorem
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
coe_inv
null
mul_hatInv_cancel {x : hat K} (x_ne : x ≠ 0) : x * hatInv x = 1 := by haveI : T1Space (hat K) := T2Space.t1Space let f := fun x : hat K => x * hatInv x let c := (fun (x : K) => (x : hat K)) change f x = 1 have cont : ContinuousAt f x := by fun_prop (disch := assumption) have clo : x ∈ closure (c '' {0}ᶜ) := by have := isDenseInducing_coe.dense x rw [← image_univ, show (univ : Set K) = {0} ∪ {0}ᶜ from (union_compl_self _).symm, image_union] at this apply mem_closure_of_mem_closure_union this rw [image_singleton] exact compl_singleton_mem_nhds x_ne have fxclo : f x ∈ closure (f '' (c '' {0}ᶜ)) := mem_closure_image cont clo have : f '' (c '' {0}ᶜ) ⊆ {1} := by rw [image_image] rintro _ ⟨z, z_ne, rfl⟩ rw [mem_singleton_iff] rw [mem_compl_singleton_iff] at z_ne dsimp [f] rw [hatInv_extends z_ne, ← coe_mul] rw [mul_inv_cancel₀ z_ne, coe_one] replace fxclo := closure_mono this fxclo rwa [closure_singleton, mem_singleton_iff] at fxclo
theorem
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
mul_hatInv_cancel
null
instField : Field (hat K) where mul_inv_cancel := fun x x_ne => by simp only [Inv.inv, if_neg x_ne, mul_hatInv_cancel x_ne] inv_zero := by simp only [Inv.inv, ite_true] nnqsmul := _ nnqsmul_def := fun _ _ => rfl qsmul := _ qsmul_def := fun _ _ => rfl
instance
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
instField
null
Subfield.completableTopField (K : Subfield L) : CompletableTopField K where nice F F_cau inf_F := by let i : K →+* L := K.subtype have hi : IsUniformInducing i := isUniformEmbedding_subtype_val.isUniformInducing rw [← hi.cauchy_map_iff] at F_cau ⊢ rw [map_comm (show (i ∘ fun x => x⁻¹) = (fun x => x⁻¹) ∘ i by ext; rfl)] apply CompletableTopField.nice _ F_cau rw [← Filter.push_pull', ← map_zero i, ← hi.isInducing.nhds_eq_comap, inf_F, Filter.map_bot]
instance
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
Subfield.completableTopField
null
IsUniformInducing.completableTopField [UniformSpace α] [T0Space α] {f : α →+* β} (hf : IsUniformInducing f) : CompletableTopField α := by refine CompletableTopField.mk (fun F F_cau inf_F => ?_) rw [← IsUniformInducing.cauchy_map_iff hf] at F_cau ⊢ have h_comm : (f ∘ fun x => x⁻¹) = (fun x => x⁻¹) ∘ f := by ext; simp only [Function.comp_apply, map_inv₀] rw [Filter.map_comm h_comm] apply CompletableTopField.nice _ F_cau rw [← Filter.push_pull', ← map_zero f, ← hf.isInducing.nhds_eq_comap, inf_F, Filter.map_bot]
theorem
Topology
[ "Mathlib.RingTheory.SimpleRing.Basic", "Mathlib.Topology.Algebra.Field", "Mathlib.Topology.Algebra.UniformRing" ]
Mathlib/Topology/Algebra/UniformField.lean
IsUniformInducing.completableTopField
The pullback of a completable topological field along a uniform inducing ring homomorphism is a completable topological field.
protected uniformSpace : UniformSpace G := @IsTopologicalAddGroup.toUniformSpace G _ B.topology B.isTopologicalAddGroup
def
Topology
[ "Mathlib.Topology.Algebra.FilterBasis", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformFilterBasis.lean
uniformSpace
The uniform space structure associated to an abelian group filter basis via the associated topological abelian group structure.
protected isUniformAddGroup : @IsUniformAddGroup G B.uniformSpace _ := @isUniformAddGroup_of_addCommGroup G _ B.topology B.isTopologicalAddGroup @[deprecated (since := "2025-03-27")] alias uniformAddGroup := AddGroupFilterBasis.isUniformAddGroup
theorem
Topology
[ "Mathlib.Topology.Algebra.FilterBasis", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformFilterBasis.lean
isUniformAddGroup
The uniform space structure associated to an abelian group filter basis via the associated topological abelian group structure is compatible with its group structure.
cauchy_iff {F : Filter G} : @Cauchy G B.uniformSpace F ↔ F.NeBot ∧ ∀ U ∈ B, ∃ M ∈ F, ∀ᵉ (x ∈ M) (y ∈ M), y - x ∈ U := by letI := B.uniformSpace haveI := B.isUniformAddGroup suffices F ×ˢ F ≤ uniformity G ↔ ∀ U ∈ B, ∃ M ∈ F, ∀ᵉ (x ∈ M) (y ∈ M), y - x ∈ U by constructor <;> rintro ⟨h', h⟩ <;> refine ⟨h', ?_⟩ <;> [rwa [← this]; rwa [this]] rw [uniformity_eq_comap_nhds_zero G, ← map_le_iff_le_comap] change Tendsto _ _ _ ↔ _ simp [(basis_sets F).prod_self.tendsto_iff B.nhds_zero_hasBasis, @forall_swap (_ ∈ _) G]
theorem
Topology
[ "Mathlib.Topology.Algebra.FilterBasis", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformFilterBasis.lean
cauchy_iff
null
UniformContinuousConstVAdd [VAdd M X] : Prop where uniformContinuous_const_vadd : ∀ c : M, UniformContinuous (c +ᵥ · : X → X)
class
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
UniformContinuousConstVAdd
An additive action such that for all `c`, the map `fun x ↦ c +ᵥ x` is uniformly continuous.
@[to_additive] UniformContinuousConstSMul [SMul M X] : Prop where uniformContinuous_const_smul : ∀ c : M, UniformContinuous (c • · : X → X) export UniformContinuousConstVAdd (uniformContinuous_const_vadd) export UniformContinuousConstSMul (uniformContinuous_const_smul)
class
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
UniformContinuousConstSMul
A multiplicative action such that for all `c`, the map `fun x ↦ c • x` is uniformly continuous.
AddMonoid.uniformContinuousConstSMul_nat [AddGroup X] [IsUniformAddGroup X] : UniformContinuousConstSMul ℕ X := ⟨uniformContinuous_const_nsmul⟩
instance
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
AddMonoid.uniformContinuousConstSMul_nat
null
AddGroup.uniformContinuousConstSMul_int [AddGroup X] [IsUniformAddGroup X] : UniformContinuousConstSMul ℤ X := ⟨uniformContinuous_const_zsmul⟩
instance
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
AddGroup.uniformContinuousConstSMul_int
null
uniformContinuousConstSMul_of_continuousConstSMul [Monoid R] [AddGroup M] [DistribMulAction R M] [UniformSpace M] [IsUniformAddGroup M] [ContinuousConstSMul R M] : UniformContinuousConstSMul R M := ⟨fun r => uniformContinuous_of_continuousAt_zero (DistribMulAction.toAddMonoidHom M r) (Continuous.continuousAt (continuous_const_smul r))⟩
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
uniformContinuousConstSMul_of_continuousConstSMul
A `DistribMulAction` that is continuous on a uniform group is uniformly continuous. This can't be an instance due to it forming a loop with `UniformContinuousConstSMul.to_continuousConstSMul`
Ring.uniformContinuousConstSMul [Ring R] [UniformSpace R] [IsUniformAddGroup R] [ContinuousMul R] : UniformContinuousConstSMul R R := uniformContinuousConstSMul_of_continuousConstSMul _ _
instance
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
Ring.uniformContinuousConstSMul
The action of `Semiring.toModule` is uniformly continuous.
Ring.uniformContinuousConstSMul_op [Ring R] [UniformSpace R] [IsUniformAddGroup R] [ContinuousMul R] : UniformContinuousConstSMul Rᵐᵒᵖ R := uniformContinuousConstSMul_of_continuousConstSMul _ _
instance
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
Ring.uniformContinuousConstSMul_op
The action of `Semiring.toOppositeModule` is uniformly continuous.
@[to_additive] UniformContinuous.const_smul [UniformContinuousConstSMul M X] {f : Y → X} (hf : UniformContinuous f) (c : M) : UniformContinuous (c • f) := (uniformContinuous_const_smul c).comp hf @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
UniformContinuous.const_smul
null
IsUniformInducing.uniformContinuousConstSMul [SMul M Y] [UniformContinuousConstSMul M Y] {f : X → Y} (hf : IsUniformInducing f) (hsmul : ∀ (c : M) x, f (c • x) = c • f x) : UniformContinuousConstSMul M X where uniformContinuous_const_smul c := by simpa only [hf.uniformContinuous_iff, Function.comp_def, hsmul] using hf.uniformContinuous.const_smul c
lemma
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
IsUniformInducing.uniformContinuousConstSMul
null
@[to_additive] MulOpposite.uniformContinuousConstSMul [UniformContinuousConstSMul M X] : UniformContinuousConstSMul M Xᵐᵒᵖ := ⟨fun c => MulOpposite.uniformContinuous_op.comp <| MulOpposite.uniformContinuous_unop.const_smul c⟩
instance
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
MulOpposite.uniformContinuousConstSMul
null
@[to_additive] IsUniformGroup.to_uniformContinuousConstSMul {G : Type u} [Group G] [UniformSpace G] [IsUniformGroup G] : UniformContinuousConstSMul G G := ⟨fun _ => uniformContinuous_const.mul uniformContinuous_id⟩
instance
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
IsUniformGroup.to_uniformContinuousConstSMul
null
UniformContinuous.const_mul' [UniformContinuousConstSMul R R] {f : β → R} (hf : UniformContinuous f) (a : R) : UniformContinuous fun x ↦ a * f x := hf.const_smul a
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
UniformContinuous.const_mul'
null
UniformContinuous.mul_const' [UniformContinuousConstSMul Rᵐᵒᵖ R] {f : β → R} (hf : UniformContinuous f) (a : R) : UniformContinuous fun x ↦ f x * a := hf.const_smul (MulOpposite.op a)
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
UniformContinuous.mul_const'
null
uniformContinuous_mul_left' [UniformContinuousConstSMul R R] (a : R) : UniformContinuous fun b : R => a * b := uniformContinuous_id.const_mul' _
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
uniformContinuous_mul_left'
null
uniformContinuous_mul_right' [UniformContinuousConstSMul Rᵐᵒᵖ R] (a : R) : UniformContinuous fun b : R => b * a := uniformContinuous_id.mul_const' _
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
uniformContinuous_mul_right'
null
UniformContinuous.div_const' {R β : Type*} [DivisionRing R] [UniformSpace R] [UniformContinuousConstSMul Rᵐᵒᵖ R] [UniformSpace β] {f : β → R} (hf : UniformContinuous f) (a : R) : UniformContinuous fun x ↦ f x / a := by simpa [div_eq_mul_inv] using hf.mul_const' a⁻¹
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
UniformContinuous.div_const'
null
uniformContinuous_div_const' {R : Type*} [DivisionRing R] [UniformSpace R] [UniformContinuousConstSMul Rᵐᵒᵖ R] (a : R) : UniformContinuous fun b : R => b / a := uniformContinuous_id.div_const' _
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
uniformContinuous_div_const'
null
@[to_additive] IsUnit.smul_uniformity [Monoid M] [MulAction M X] [UniformContinuousConstSMul M X] {c : M} (hc : IsUnit c) : c • 𝓤 X = 𝓤 X := let ⟨d, hcd⟩ := hc.exists_right_inv have cU : c • 𝓤 X ≤ 𝓤 X := uniformContinuous_const_smul c have dU : d • 𝓤 X ≤ 𝓤 X := uniformContinuous_const_smul d le_antisymm cU <| by simpa [smul_smul, hcd] using Filter.smul_filter_le_smul_filter (a := c) dU @[to_additive (attr := simp)]
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
IsUnit.smul_uniformity
null
smul_uniformity [Group M] [MulAction M X] [UniformContinuousConstSMul M X] (c : M) : c • 𝓤 X = 𝓤 X := Group.isUnit _ |>.smul_uniformity
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
smul_uniformity
null
smul_uniformity₀ [GroupWithZero M] [MulAction M X] [UniformContinuousConstSMul M X] {c : M} (hc : c ≠ 0) : c • 𝓤 X = 𝓤 X := hc.isUnit.smul_uniformity
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
smul_uniformity₀
null
@[to_additive] smul_def (c : M) (x : Completion X) : c • x = Completion.map (c • ·) x := rfl @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
smul_def
null
@[to_additive] instIsScalarTower [SMul N X] [SMul M N] [UniformContinuousConstSMul M X] [UniformContinuousConstSMul N X] [IsScalarTower M N X] : IsScalarTower M N (Completion X) := ⟨fun m n x => by have : _ = (_ : Completion X → Completion X) := map_comp (uniformContinuous_const_smul m) (uniformContinuous_const_smul n) refine Eq.trans ?_ (congr_fun this.symm x) exact congr_arg (fun f => Completion.map f x) (funext (smul_assoc _ _))⟩ @[to_additive]
instance
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
instIsScalarTower
null
@[to_additive (attr := simp, norm_cast)] coe_smul (c : M) (x : X) : (↑(c • x) : Completion X) = c • (x : Completion X) := (map_coe (uniformContinuous_const_smul c) x).symm
theorem
Topology
[ "Mathlib.Algebra.Module.Opposite", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.IsUniformGroup.Defs" ]
Mathlib/Topology/Algebra/UniformMulAction.lean
coe_smul
null
one : One (Completion α) := ⟨(1 : α)⟩
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
one
null
mul : Mul (Completion α) := ⟨curry <| (isDenseInducing_coe.prodMap isDenseInducing_coe).extend ((↑) ∘ uncurry (· * ·))⟩ @[norm_cast]
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
mul
null
coe_one : ((1 : α) : Completion α) = 1 := rfl @[simp] lemma coe_eq_one_iff [T0Space α] {x : α} : (x : Completion α) = 1 ↔ x = 1 := Completion.coe_inj
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
coe_one
null
@[norm_cast] coe_mul (a b : α) : ((a * b : α) : Completion α) = a * b := ((isDenseInducing_coe.prodMap isDenseInducing_coe).extend_eq ((continuous_coe α).comp (@continuous_mul α _ _ _)) (a, b)).symm variable [IsUniformAddGroup α]
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
coe_mul
null
ring : Ring (Completion α) := { AddMonoidWithOne.unary, (inferInstanceAs (AddCommGroup (Completion α))), (inferInstanceAs (Mul (Completion α))), (inferInstanceAs (One (Completion α))) with zero_mul := fun a => Completion.induction_on a (isClosed_eq (continuous_const.mul continuous_id) continuous_const) fun a => by rw [← coe_zero, ← coe_mul, zero_mul] mul_zero := fun a => Completion.induction_on a (isClosed_eq (continuous_id.mul continuous_const) continuous_const) fun a => by rw [← coe_zero, ← coe_mul, mul_zero] one_mul := fun a => Completion.induction_on a (isClosed_eq (continuous_const.mul continuous_id) continuous_id) fun a => by rw [← coe_one, ← coe_mul, one_mul] mul_one := fun a => Completion.induction_on a (isClosed_eq (continuous_id.mul continuous_const) continuous_id) fun a => by rw [← coe_one, ← coe_mul, mul_one] mul_assoc := fun a b c => Completion.induction_on₃ a b c (isClosed_eq ((continuous_fst.mul (continuous_fst.comp continuous_snd)).mul (continuous_snd.comp continuous_snd)) (continuous_fst.mul ((continuous_fst.comp continuous_snd).mul (continuous_snd.comp continuous_snd)))) fun a b c => by rw [← coe_mul, ← coe_mul, ← coe_mul, ← coe_mul, mul_assoc] left_distrib := fun a b c => Completion.induction_on₃ a b c (isClosed_eq (continuous_fst.mul (Continuous.add (continuous_fst.comp continuous_snd) (continuous_snd.comp continuous_snd))) (Continuous.add (continuous_fst.mul (continuous_fst.comp continuous_snd)) (continuous_fst.mul (continuous_snd.comp continuous_snd)))) fun a b c => by rw [← coe_add, ← coe_mul, ← coe_mul, ← coe_mul, ← coe_add, mul_add] right_distrib := fun a b c => Completion.induction_on₃ a b c (isClosed_eq ((Continuous.add continuous_fst (continuous_fst.comp continuous_snd)).mul (continuous_snd.comp continuous_snd)) (Continuous.add (continuous_fst.mul (continuous_snd.comp continuous_snd)) ((continuous_fst.comp continuous_snd).mul (continuous_snd.comp continuous_snd)))) fun a b c => by rw [← coe_add, ← coe_mul, ← coe_mul, ← coe_mul, ← coe_add, add_mul] }
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
ring
null
coeRingHom : α →+* Completion α where toFun := (↑) map_one' := coe_one α map_zero' := coe_zero map_add' := coe_add map_mul' := coe_mul
def
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
coeRingHom
The map from a uniform ring to its completion, as a ring homomorphism.
continuous_coeRingHom : Continuous (coeRingHom : α → Completion α) := continuous_coe α variable {β : Type u} [UniformSpace β] [Ring β] [IsUniformAddGroup β] [IsTopologicalRing β] (f : α →+* β) (hf : Continuous f)
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
continuous_coeRingHom
null
extensionHom [CompleteSpace β] [T0Space β] : Completion α →+* β := have hf' : Continuous (f : α →+ β) := hf have hf : UniformContinuous f := uniformContinuous_addMonoidHom_of_continuous hf' { toFun := Completion.extension f map_zero' := by simp_rw [← coe_zero, extension_coe hf, f.map_zero] map_add' := fun a b => Completion.induction_on₂ a b (isClosed_eq (continuous_extension.comp continuous_add) ((continuous_extension.comp continuous_fst).add (continuous_extension.comp continuous_snd))) fun a b => by simp_rw [← coe_add, extension_coe hf, f.map_add] map_one' := by rw [← coe_one, extension_coe hf, f.map_one] map_mul' := fun a b => Completion.induction_on₂ a b (isClosed_eq (continuous_extension.comp continuous_mul) ((continuous_extension.comp continuous_fst).mul (continuous_extension.comp continuous_snd))) fun a b => by simp_rw [← coe_mul, extension_coe hf, f.map_mul] }
def
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
extensionHom
The completion extension as a ring morphism.
extensionHom_coe [CompleteSpace β] [T0Space β] (a : α) : Completion.extensionHom f hf a = f a := by simp only [Completion.extensionHom, RingHom.coe_mk, MonoidHom.coe_mk, OneHom.coe_mk, UniformSpace.Completion.extension_coe <| uniformContinuous_addMonoidHom_of_continuous hf]
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
extensionHom_coe
null
topologicalRing : IsTopologicalRing (Completion α) where continuous_add := continuous_add continuous_mul := continuous_mul
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
topologicalRing
null
mapRingHom (hf : Continuous f) : Completion α →+* Completion β := extensionHom (coeRingHom.comp f) (continuous_coeRingHom.comp hf)
def
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
mapRingHom
The completion map as a ring morphism.
mapRingHom_apply {x : UniformSpace.Completion α} : UniformSpace.Completion.mapRingHom f hf x = UniformSpace.Completion.map f x := rfl variable {f}
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
mapRingHom_apply
null
mapRingHom_coe (hf : UniformContinuous f) (a : α) : mapRingHom f hf.continuous a = f a := by rw [mapRingHom_apply, map_coe hf]
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
mapRingHom_coe
null
@[simp] map_smul_eq_mul_coe (r : R) : Completion.map (r • ·) = ((algebraMap R A r : Completion A) * ·) := by ext x refine Completion.induction_on x ?_ fun a => ?_ · exact isClosed_eq Completion.continuous_map (continuous_mul_left _) · simp_rw [map_coe (uniformContinuous_const_smul r) a, Algebra.smul_def, coe_mul]
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
map_smul_eq_mul_coe
null
algebra : Algebra R (Completion A) where algebraMap := (UniformSpace.Completion.coeRingHom : A →+* Completion A).comp (algebraMap R A) commutes' := fun r x => Completion.induction_on x (isClosed_eq (continuous_mul_left _) (continuous_mul_right _)) fun a => by simpa only [coe_mul] using congr_arg ((↑) : A → Completion A) (Algebra.commutes r a) smul_def' := fun r x => congr_fun (map_smul_eq_mul_coe A R r) x
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
algebra
null
algebraMap_def (r : R) : algebraMap R (Completion A) r = (algebraMap R A r : Completion A) := rfl
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
algebraMap_def
null
commRing : CommRing (Completion R) := { Completion.ring with mul_comm := fun a b => Completion.induction_on₂ a b (isClosed_eq (continuous_fst.mul continuous_snd) (continuous_snd.mul continuous_fst)) fun a b => by rw [← coe_mul, ← coe_mul, mul_comm] }
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
commRing
null
algebra' : Algebra R (Completion R) := by infer_instance
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
algebra'
A shortcut instance for the common case
inseparableSetoid_ring (α) [Ring α] [TopologicalSpace α] [IsTopologicalRing α] : inseparableSetoid α = Submodule.quotientRel (Ideal.closure ⊥) := Setoid.ext fun x y => addGroup_inseparable_iff.trans <| .trans (by rfl) (Submodule.quotientRel_def _).symm
theorem
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
inseparableSetoid_ring
null
sepQuotHomeomorphRingQuot (α) [CommRing α] [TopologicalSpace α] [IsTopologicalRing α] : SeparationQuotient α ≃ₜ α ⧸ (⊥ : Ideal α).closure where toEquiv := Quotient.congrRight fun x y => by rw [inseparableSetoid_ring] continuous_toFun := continuous_id.quotient_map' <| by rw [inseparableSetoid_ring]; exact fun _ _ ↦ id continuous_invFun := continuous_id.quotient_map' <| by rw [inseparableSetoid_ring]; exact fun _ _ ↦ id
def
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
sepQuotHomeomorphRingQuot
Given a topological ring `α` equipped with a uniform structure that makes subtraction uniformly continuous, get an homeomorphism between the separated quotient of `α` and the quotient ring corresponding to the closure of zero.
commRing [CommRing α] [TopologicalSpace α] [IsTopologicalRing α] : CommRing (SeparationQuotient α) := (sepQuotHomeomorphRingQuot _).commRing
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
commRing
null
sepQuotRingEquivRingQuot (α) [CommRing α] [TopologicalSpace α] [IsTopologicalRing α] : SeparationQuotient α ≃+* α ⧸ (⊥ : Ideal α).closure := (sepQuotHomeomorphRingQuot _).ringEquiv
def
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
sepQuotRingEquivRingQuot
Given a topological ring `α` equipped with a uniform structure that makes subtraction uniformly continuous, get an equivalence between the separated quotient of `α` and the quotient ring corresponding to the closure of zero.
topologicalRing [CommRing α] [TopologicalSpace α] [IsTopologicalRing α] : IsTopologicalRing (SeparationQuotient α) where toContinuousAdd := (sepQuotHomeomorphRingQuot α).isInducing.continuousAdd (sepQuotRingEquivRingQuot α) toContinuousMul := (sepQuotHomeomorphRingQuot α).isInducing.continuousMul (sepQuotRingEquivRingQuot α) toContinuousNeg := (sepQuotHomeomorphRingQuot α).isInducing.continuousNeg <| map_neg (sepQuotRingEquivRingQuot α)
instance
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
topologicalRing
null
noncomputable IsDenseInducing.extendRingHom {i : α →+* β} {f : α →+* γ} (ue : IsUniformInducing i) (dr : DenseRange i) (hf : UniformContinuous f) : β →+* γ where toFun := (ue.isDenseInducing dr).extend f map_one' := by convert IsDenseInducing.extend_eq (ue.isDenseInducing dr) hf.continuous 1 exacts [i.map_one.symm, f.map_one.symm] map_zero' := by convert IsDenseInducing.extend_eq (ue.isDenseInducing dr) hf.continuous 0 <;> simp only [map_zero] map_add' := by have h := (uniformContinuous_uniformly_extend ue dr hf).continuous refine fun x y => DenseRange.induction_on₂ dr ?_ (fun a b => ?_) x y · exact isClosed_eq (Continuous.comp h continuous_add) ((h.comp continuous_fst).add (h.comp continuous_snd)) · simp_rw [← i.map_add, IsDenseInducing.extend_eq (ue.isDenseInducing dr) hf.continuous _, ← f.map_add] map_mul' := by have h := (uniformContinuous_uniformly_extend ue dr hf).continuous refine fun x y => DenseRange.induction_on₂ dr ?_ (fun a b => ?_) x y · exact isClosed_eq (Continuous.comp h continuous_mul) ((h.comp continuous_fst).mul (h.comp continuous_snd)) · simp_rw [← i.map_mul, IsDenseInducing.extend_eq (ue.isDenseInducing dr) hf.continuous _, ← f.map_mul]
def
Topology
[ "Mathlib.Algebra.Algebra.Defs", "Mathlib.Algebra.Module.Submodule.Lattice", "Mathlib.Algebra.Ring.TransferInstance", "Mathlib.Topology.Algebra.GroupCompletion", "Mathlib.Topology.Algebra.Ring.Ideal", "Mathlib.Topology.Algebra.IsUniformGroup.Basic" ]
Mathlib/Topology/Algebra/UniformRing.lean
IsDenseInducing.extendRingHom
The dense inducing extension as a ring homomorphism.
nhds_zero : 𝓝 (0 : Γ₀) = ⨅ γ ≠ 0, 𝓟 (Iio γ) := by rw [nhds_eq_update, update_self]
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
nhds_zero
The topology on a linearly ordered commutative group with a zero element adjoined. A subset U is open if 0 ∉ U or if there is an invertible element γ₀ such that {γ | γ < γ₀} ⊆ U. -/ scoped instance (priority := 100) topologicalSpace : TopologicalSpace Γ₀ := nhdsAdjoint 0 <| ⨅ γ ≠ 0, 𝓟 (Iio γ) theorem nhds_eq_update : (𝓝 : Γ₀ → Filter Γ₀) = update pure 0 (⨅ γ ≠ 0, 𝓟 (Iio γ)) := by rw [nhds_nhdsAdjoint, sup_of_le_right] exact le_iInf₂ fun γ hγ ↦ le_principal_iff.2 <| zero_lt_iff.2 hγ /-! ### Neighbourhoods of zero
hasBasis_nhds_zero : (𝓝 (0 : Γ₀)).HasBasis (fun γ : Γ₀ => γ ≠ 0) Iio := by rw [nhds_zero] refine hasBasis_biInf_principal ?_ ⟨1, one_ne_zero⟩ exact directedOn_iff_directed.2 (Monotone.directed_ge fun a b hab => Iio_subset_Iio hab)
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
hasBasis_nhds_zero
In a linearly ordered group with zero element adjoined, `U` is a neighbourhood of `0` if and only if there exists a nonzero element `γ₀` such that `Iio γ₀ ⊆ U`.
Iio_mem_nhds_zero (hγ : γ ≠ 0) : Iio γ ∈ 𝓝 (0 : Γ₀) := hasBasis_nhds_zero.mem_of_mem hγ
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
Iio_mem_nhds_zero
null
nhds_zero_of_units (γ : Γ₀ˣ) : Iio ↑γ ∈ 𝓝 (0 : Γ₀) := Iio_mem_nhds_zero γ.ne_zero
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
nhds_zero_of_units
If `γ` is an invertible element of a linearly ordered group with zero element adjoined, then `Iio (γ : Γ₀)` is a neighbourhood of `0`.
tendsto_zero : Tendsto f l (𝓝 (0 : Γ₀)) ↔ ∀ (γ₀) (_ : γ₀ ≠ 0), ∀ᶠ x in l, f x < γ₀ := by simp [nhds_zero] /-!
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
tendsto_zero
null
@[simp] nhds_of_ne_zero {γ : Γ₀} (h₀ : γ ≠ 0) : 𝓝 γ = pure γ := nhds_nhdsAdjoint_of_ne _ h₀
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
nhds_of_ne_zero
The neighbourhood filter of a nonzero element consists of all sets containing that element.
nhds_coe_units (γ : Γ₀ˣ) : 𝓝 (γ : Γ₀) = pure (γ : Γ₀) := nhds_of_ne_zero γ.ne_zero
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
nhds_coe_units
The neighbourhood filter of an invertible element consists of all sets containing that element.
singleton_mem_nhds_of_units (γ : Γ₀ˣ) : ({↑γ} : Set Γ₀) ∈ 𝓝 (γ : Γ₀) := by simp
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
singleton_mem_nhds_of_units
If `γ` is an invertible element of a linearly ordered group with zero element adjoined, then `{γ}` is a neighbourhood of `γ`.
singleton_mem_nhds_of_ne_zero (h : γ ≠ 0) : ({γ} : Set Γ₀) ∈ 𝓝 (γ : Γ₀) := by simp [h]
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
singleton_mem_nhds_of_ne_zero
If `γ` is a nonzero element of a linearly ordered group with zero element adjoined, then `{γ}` is a neighbourhood of `γ`.
hasBasis_nhds_of_ne_zero {x : Γ₀} (h : x ≠ 0) : HasBasis (𝓝 x) (fun _ : Unit => True) fun _ => {x} := by rw [nhds_of_ne_zero h] exact hasBasis_pure _
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
hasBasis_nhds_of_ne_zero
null
hasBasis_nhds_units (γ : Γ₀ˣ) : HasBasis (𝓝 (γ : Γ₀)) (fun _ : Unit => True) fun _ => {↑γ} := hasBasis_nhds_of_ne_zero γ.ne_zero
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
hasBasis_nhds_units
null
tendsto_of_ne_zero {γ : Γ₀} (h : γ ≠ 0) : Tendsto f l (𝓝 γ) ↔ ∀ᶠ x in l, f x = γ := by rw [nhds_of_ne_zero h, tendsto_pure]
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
tendsto_of_ne_zero
null
tendsto_units {γ₀ : Γ₀ˣ} : Tendsto f l (𝓝 (γ₀ : Γ₀)) ↔ ∀ᶠ x in l, f x = γ₀ := tendsto_of_ne_zero γ₀.ne_zero
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
tendsto_units
null
Iio_mem_nhds (h : γ₁ < γ₂) : Iio γ₂ ∈ 𝓝 γ₁ := by rcases eq_or_ne γ₁ 0 with (rfl | h₀) <;> simp [*, h.ne', Iio_mem_nhds_zero] /-!
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
Iio_mem_nhds
null
isOpen_iff {s : Set Γ₀} : IsOpen s ↔ (0 : Γ₀) ∉ s ∨ ∃ γ, γ ≠ 0 ∧ Iio γ ⊆ s := by rw [isOpen_iff_mem_nhds, ← and_forall_ne (0 : Γ₀)] simp +contextual [nhds_of_ne_zero, imp_iff_not_or, hasBasis_nhds_zero.mem_iff]
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
isOpen_iff
null
isClosed_iff {s : Set Γ₀} : IsClosed s ↔ (0 : Γ₀) ∈ s ∨ ∃ γ, γ ≠ 0 ∧ s ⊆ Ici γ := by simp only [← isOpen_compl_iff, isOpen_iff, mem_compl_iff, not_not, ← compl_Ici, compl_subset_compl]
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
isClosed_iff
null
isOpen_Iio {a : Γ₀} : IsOpen (Iio a) := isOpen_iff.mpr <| imp_iff_not_or.mp fun ha => ⟨a, ne_of_gt ha, Subset.rfl⟩ /-!
theorem
Topology
[ "Mathlib.Algebra.Order.GroupWithZero.Canonical", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Order.OrderClosed", "Mathlib.Topology.Separation.Regular" ]
Mathlib/Topology/Algebra/WithZeroTopology.lean
isOpen_Iio
null
BaireMeasurableSet (s : Set α) : Prop := @MeasurableSet _ (eventuallyMeasurableSpace (borel _) (residual _)) s variable {s t : Set α}
def
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
BaireMeasurableSet
Notation for `=ᶠ[residual _]`. That is, eventual equality with respect to the filter of residual sets. -/ scoped[Topology] notation:50 f " =ᵇ " g:50 => Filter.EventuallyEq (residual _) f g /-- Notation to say that a property of points in a topological space holds almost everywhere in the sense of Baire category. That is, on a residual set. -/ scoped[Topology] notation3 "∀ᵇ " (...) ", " r:(scoped p => Filter.Eventually p <| residual _) => r /-- Notation to say that a property of points in a topological space holds on a nonmeager set. -/ scoped[Topology] notation3 "∃ᵇ " (...) ", " r:(scoped p => Filter.Frequently p <| residual _) => r variable {α} theorem coborder_mem_residual {s : Set α} (hs : IsLocallyClosed s) : coborder s ∈ residual α := residual_of_dense_open hs.isOpen_coborder dense_coborder theorem closure_residualEq {s : Set α} (hs : IsLocallyClosed s) : closure s =ᵇ s := by rw [Filter.eventuallyEq_set] filter_upwards [coborder_mem_residual hs] with x hx nth_rewrite 2 [← closure_inter_coborder (s := s)] simp [hx] /-- We say a set is a `BaireMeasurableSet` if it differs from some Borel set by a meager set. This forms a σ-algebra. It is equivalent, and a more standard definition, to say that the set differs from some *open* set by a meager set. See `BaireMeasurableSet.iff_residualEq_isOpen`
of_mem_residual (h : s ∈ residual _) : BaireMeasurableSet s := eventuallyMeasurableSet_of_mem_filter (α := α) h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
of_mem_residual
null
_root_.MeasurableSet.baireMeasurableSet [MeasurableSpace α] [BorelSpace α] (h : MeasurableSet s) : BaireMeasurableSet s := by borelize α exact h.eventuallyMeasurableSet
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
_root_.MeasurableSet.baireMeasurableSet
null
_root_.IsOpen.baireMeasurableSet (h : IsOpen s) : BaireMeasurableSet s := by borelize α exact h.measurableSet.baireMeasurableSet
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
_root_.IsOpen.baireMeasurableSet
null
compl (h : BaireMeasurableSet s) : BaireMeasurableSet sᶜ := MeasurableSet.compl h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
compl
null
of_compl (h : BaireMeasurableSet sᶜ) : BaireMeasurableSet s := MeasurableSet.of_compl h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
of_compl
null
_root_.IsMeagre.baireMeasurableSet (h : IsMeagre s) : BaireMeasurableSet s := (of_mem_residual h).of_compl
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
_root_.IsMeagre.baireMeasurableSet
null
iUnion {ι : Sort*} [Countable ι] {s : ι → Set α} (h : ∀ i, BaireMeasurableSet (s i)) : BaireMeasurableSet (⋃ i, s i) := MeasurableSet.iUnion h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
iUnion
null
biUnion {ι : Type*} {s : ι → Set α} {t : Set ι} (ht : t.Countable) (h : ∀ i ∈ t, BaireMeasurableSet (s i)) : BaireMeasurableSet (⋃ i ∈ t, s i) := MeasurableSet.biUnion ht h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
biUnion
null
sUnion {s : Set (Set α)} (hs : s.Countable) (h : ∀ t ∈ s, BaireMeasurableSet t) : BaireMeasurableSet (⋃₀ s) := MeasurableSet.sUnion hs h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
sUnion
null
iInter {ι : Sort*} [Countable ι] {s : ι → Set α} (h : ∀ i, BaireMeasurableSet (s i)) : BaireMeasurableSet (⋂ i, s i) := MeasurableSet.iInter h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
iInter
null
biInter {ι : Type*} {s : ι → Set α} {t : Set ι} (ht : t.Countable) (h : ∀ i ∈ t, BaireMeasurableSet (s i)) : BaireMeasurableSet (⋂ i ∈ t, s i) := MeasurableSet.biInter ht h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
biInter
null
sInter {s : Set (Set α)} (hs : s.Countable) (h : ∀ t ∈ s, BaireMeasurableSet t) : BaireMeasurableSet (⋂₀ s) := MeasurableSet.sInter hs h
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
sInter
null
union (hs : BaireMeasurableSet s) (ht : BaireMeasurableSet t) : BaireMeasurableSet (s ∪ t) := MeasurableSet.union hs ht
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
union
null
inter (hs : BaireMeasurableSet s) (ht : BaireMeasurableSet t) : BaireMeasurableSet (s ∩ t) := MeasurableSet.inter hs ht
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
inter
null
diff (hs : BaireMeasurableSet s) (ht : BaireMeasurableSet t) : BaireMeasurableSet (s \ t) := MeasurableSet.diff hs ht
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
diff
null
congr (hs : BaireMeasurableSet s) (h : s =ᵇ t) : BaireMeasurableSet t := EventuallyMeasurableSet.congr (α := α) hs h.symm
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
congr
null
MeasurableSet.residualEq_isOpen [MeasurableSpace α] [BorelSpace α] (h : MeasurableSet s) : ∃ u : Set α, IsOpen u ∧ s =ᵇ u := by induction s, h using MeasurableSet.induction_on_open with | isOpen U hU => exact ⟨U, hU, .rfl⟩ | compl s _ ihs => obtain ⟨U, Uo, hsU⟩ := ihs use (closure U)ᶜ, isClosed_closure.isOpen_compl exact .compl <| hsU.trans <| .symm <| closure_residualEq Uo.isLocallyClosed | iUnion f _ _ ihf => choose u uo su using ihf exact ⟨⋃ i, u i, isOpen_iUnion uo, EventuallyEq.countable_iUnion su⟩
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
MeasurableSet.residualEq_isOpen
Any Borel set differs from some open set by a meager set.
BaireMeasurableSet.residualEq_isOpen (h : BaireMeasurableSet s) : ∃ u : Set α, (IsOpen u) ∧ s =ᵇ u := by borelize α rcases h with ⟨t, ht, hst⟩ rcases ht.residualEq_isOpen with ⟨u, hu, htu⟩ exact ⟨u, hu, hst.trans htu⟩
theorem
Topology
[ "Mathlib.Topology.LocallyClosed", "Mathlib.MeasureTheory.MeasurableSpace.EventuallyMeasurable", "Mathlib.MeasureTheory.Constructions.BorelSpace.Basic" ]
Mathlib/Topology/Baire/BaireMeasurable.lean
BaireMeasurableSet.residualEq_isOpen
Any `BaireMeasurableSet` differs from some open set by a meager set.