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isClosedEmbedding_toCloseds [T2Space α] [CompleteSpace α] : IsClosedEmbedding (toCloseds (α := α))
Compacts.isClosedEmbedding_toCloseds.comp isClosedEmbedding_toCompacts
theorem
TopologicalSpace.NonemptyCompacts.isClosedEmbedding_toCloseds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "CompleteSpace", "T2Space" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformEmbedding_toCompacts : IsUniformEmbedding (toCompacts (α := α))
where injective := toCompacts_injective comap_uniformity := Filter.comap_comap
theorem
TopologicalSpace.NonemptyCompacts.isUniformEmbedding_toCompacts
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "Filter.comap_comap", "IsUniformEmbedding" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_toCompacts : UniformContinuous (toCompacts (α := α))
isUniformEmbedding_toCompacts.uniformContinuous
theorem
TopologicalSpace.NonemptyCompacts.uniformContinuous_toCompacts
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_subsets_of_totallyBounded {t : Set α} (ht : TotallyBounded t) : TotallyBounded {K : NonemptyCompacts α | ↑K ⊆ t}
totallyBounded_preimage isUniformEmbedding_coe.isUniformInducing ht.powerset_hausdorff
theorem
TopologicalSpace.NonemptyCompacts.totallyBounded_subsets_of_totallyBounded
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "Set", "TotallyBounded", "totallyBounded_preimage" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformEmbedding_singleton : IsUniformEmbedding ({·} : α → NonemptyCompacts α)
isUniformEmbedding_coe.of_comp_iff.mp UniformSpace.hausdorff.isUniformEmbedding_singleton
theorem
TopologicalSpace.NonemptyCompacts.isUniformEmbedding_singleton
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "IsUniformEmbedding", "UniformSpace.hausdorff.isUniformEmbedding_singleton" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_singleton : UniformContinuous ({·} : α → NonemptyCompacts α)
isUniformEmbedding_singleton.uniformContinuous
theorem
TopologicalSpace.NonemptyCompacts.uniformContinuous_singleton
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_sup : UniformContinuous (fun x : NonemptyCompacts α × NonemptyCompacts α => x.1 ⊔ x.2)
isUniformEmbedding_coe.uniformContinuous_iff.mpr <| UniformSpace.hausdorff.uniformContinuous_union.comp <| uniformContinuous_coe.prodMap uniformContinuous_coe
theorem
TopologicalSpace.NonemptyCompacts.uniformContinuous_sup
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.UniformContinuous.sup_nonemptyCompacts {f g : α → NonemptyCompacts β} (hf : UniformContinuous f) (hg : UniformContinuous g) : UniformContinuous (fun x => f x ⊔ g x)
uniformContinuous_sup.comp <| hf.prodMk hg
theorem
UniformContinuous.sup_nonemptyCompacts
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_prod : UniformContinuous (fun x : NonemptyCompacts α × NonemptyCompacts β => x.1 ×ˢ x.2)
isUniformEmbedding_coe.uniformContinuous_iff.mpr <| UniformSpace.hausdorff.uniformContinuous_prod.comp <| uniformContinuous_coe.prodMap uniformContinuous_coe
theorem
TopologicalSpace.NonemptyCompacts.uniformContinuous_prod
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.UniformContinuous.prod_nonemptyCompacts {f : α → NonemptyCompacts β} {g : α → NonemptyCompacts γ} (hf : UniformContinuous f) (hg : UniformContinuous g) : UniformContinuous (fun x => f x ×ˢ g x)
uniformContinuous_prod.comp (hf.prodMk hg)
theorem
UniformContinuous.prod_nonemptyCompacts
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.UniformContinuous.nonemptyCompacts_map {f : α → β} (hf : UniformContinuous f) : UniformContinuous (NonemptyCompacts.map f hf.continuous)
isUniformEmbedding_coe.uniformContinuous_iff.mpr <| hf.image_hausdorff.comp uniformContinuous_coe
theorem
UniformContinuous.nonemptyCompacts_map
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.IsUniformInducing.nonemptyCompacts_map {f : α → β} (hf : IsUniformInducing f) : IsUniformInducing (NonemptyCompacts.map f hf.uniformContinuous.continuous)
.of_comp hf.uniformContinuous.nonemptyCompacts_map uniformContinuous_coe <| hf.image_hausdorff.comp isUniformEmbedding_coe.isUniformInducing
theorem
IsUniformInducing.nonemptyCompacts_map
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "IsUniformInducing" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.IsUniformEmbedding.nonemptyCompacts_map {f : α → β} (hf : IsUniformEmbedding f) : IsUniformEmbedding (NonemptyCompacts.map f hf.uniformContinuous.continuous)
where __ := hf.isUniformInducing.nonemptyCompacts_map injective := map_injective hf.uniformContinuous.continuous hf.injective
theorem
IsUniformEmbedding.nonemptyCompacts_map
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "IsUniformEmbedding" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
discreteUniformity_iff : DiscreteUniformity (NonemptyCompacts α) ↔ DiscreteUniformity α
⟨fun _ => isUniformEmbedding_singleton.discreteUniformity, fun _ => inferInstance⟩
theorem
TopologicalSpace.NonemptyCompacts.discreteUniformity_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "DiscreteUniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
completeSpace_iff : CompleteSpace (NonemptyCompacts α) ↔ CompleteSpace α
by refine ⟨fun _ => ⟨fun {f} hf => ?_⟩, fun _ => inferInstance⟩ obtain ⟨K, hK⟩ := CompleteSpace.complete <| hf.map uniformContinuous_singleton obtain ⟨x, hx⟩ := K.nonempty exists x rw [(nhds_basis_opens x).ge_iff] intro U ⟨hxU, hU⟩ filter_upwards [hK <| (isOpen_inter_nonempty_of_isOpen hU).mem_nhds ⟨x, hx...
theorem
TopologicalSpace.NonemptyCompacts.completeSpace_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "CompleteSpace", "nhds_basis_opens" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.TopologicalSpace.Compacts.completeSpace_iff : CompleteSpace (Compacts α) ↔ CompleteSpace α
where mp _ := NonemptyCompacts.completeSpace_iff.mp <| NonemptyCompacts.isUniformEmbedding_toCompacts.completeSpace isClosedEmbedding_toCompacts.isClosed_range.isComplete mpr _ := inferInstance
theorem
TopologicalSpace.Compacts.completeSpace_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Closeds.lean
[ "Mathlib.Topology.UniformSpace.Compact" ]
[ "CompleteSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
lebesgue_number_lemma {ι : Sort*} {U : ι → Set α} (hK : IsCompact K) (hopen : ∀ i, IsOpen (U i)) (hcover : K ⊆ ⋃ i, U i) : ∃ V ∈ 𝓤 α, ∀ x ∈ K, ∃ i, ball x V ⊆ U i
by have : ∀ x ∈ K, ∃ i, ∃ V ∈ 𝓤 α, ball x (V ○ V) ⊆ U i := fun x hx ↦ by obtain ⟨i, hi⟩ := mem_iUnion.1 (hcover hx) rw [← (hopen i).mem_nhds_iff, nhds_eq_comap_uniformity, ← lift'_comp_uniformity] at hi exact ⟨i, (((basis_sets _).lift' <| monotone_id.relComp monotone_id).comap _).mem_iff.1 hi⟩ choose i...
theorem
lebesgue_number_lemma
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "IsOpen", "Set", "comap", "lift'_comp_uniformity", "mem_nhds_iff", "monotone_id", "nhds_eq_comap_uniformity" ]
Let `c : ι → Set α` be an open cover of a compact set `s`. Then there exists an entourage `n` such that for each `x ∈ s` its `n`-neighborhood is contained in some `c i`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
lebesgue_number_lemma_nhds' {U : (x : α) → x ∈ K → Set α} (hK : IsCompact K) (hU : ∀ x hx, U x hx ∈ 𝓝 x) : ∃ V ∈ 𝓤 α, ∀ x ∈ K, ∃ y : K, ball x V ⊆ U y y.2
by rcases lebesgue_number_lemma (U := fun x : K => interior (U x x.2)) hK (fun _ => isOpen_interior) (fun x hx => mem_iUnion.2 ⟨⟨x, hx⟩, mem_interior_iff_mem_nhds.2 (hU x hx)⟩) with ⟨V, V_uni, hV⟩ exact ⟨V, V_uni, fun x hx => (hV x hx).imp fun _ hy => hy.trans interior_subset⟩
theorem
lebesgue_number_lemma_nhds'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "interior", "isOpen_interior", "lebesgue_number_lemma" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
lebesgue_number_lemma_nhds {U : α → Set α} (hK : IsCompact K) (hU : ∀ x ∈ K, U x ∈ 𝓝 x) : ∃ V ∈ 𝓤 α, ∀ x ∈ K, ∃ y, ball x V ⊆ U y
by rcases lebesgue_number_lemma (U := fun x => interior (U x)) hK (fun _ => isOpen_interior) (fun x hx => mem_iUnion.2 ⟨x, mem_interior_iff_mem_nhds.2 (hU x hx)⟩) with ⟨V, V_uni, hV⟩ exact ⟨V, V_uni, fun x hx => (hV x hx).imp fun _ hy => hy.trans interior_subset⟩
theorem
lebesgue_number_lemma_nhds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "interior", "isOpen_interior", "lebesgue_number_lemma" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
lebesgue_number_lemma_nhdsWithin' {U : (x : α) → x ∈ K → Set α} (hK : IsCompact K) (hU : ∀ x hx, U x hx ∈ 𝓝[K] x) : ∃ V ∈ 𝓤 α, ∀ x ∈ K, ∃ y : K, ball x V ∩ K ⊆ U y y.2
(lebesgue_number_lemma_nhds' hK (fun x hx => Filter.mem_inf_principal'.1 (hU x hx))).imp fun _ ⟨V_uni, hV⟩ => ⟨V_uni, fun x hx => (hV x hx).imp fun _ hy => (inter_subset _ _ _).2 hy⟩
theorem
lebesgue_number_lemma_nhdsWithin'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "lebesgue_number_lemma_nhds'" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
lebesgue_number_lemma_nhdsWithin {U : α → Set α} (hK : IsCompact K) (hU : ∀ x ∈ K, U x ∈ 𝓝[K] x) : ∃ V ∈ 𝓤 α, ∀ x ∈ K, ∃ y, ball x V ∩ K ⊆ U y
(lebesgue_number_lemma_nhds hK (fun x hx => Filter.mem_inf_principal'.1 (hU x hx))).imp fun _ ⟨V_uni, hV⟩ => ⟨V_uni, fun x hx => (hV x hx).imp fun _ hy => (inter_subset _ _ _).2 hy⟩
theorem
lebesgue_number_lemma_nhdsWithin
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "lebesgue_number_lemma_nhds" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.lebesgue_number_lemma {ι' ι : Sort*} {p : ι' → Prop} {V : ι' → Set (α × α)} {U : ι → Set α} (hbasis : (𝓤 α).HasBasis p V) (hK : IsCompact K) (hopen : ∀ j, IsOpen (U j)) (hcover : K ⊆ ⋃ j, U j) : ∃ i, p i ∧ ∀ x ∈ K, ∃ j, ball x (V i) ⊆ U j
by refine (hbasis.exists_iff ?_).1 (lebesgue_number_lemma hK hopen hcover) exact fun s t hst ht x hx ↦ (ht x hx).imp fun i hi ↦ Subset.trans (ball_mono hst _) hi
theorem
Filter.HasBasis.lebesgue_number_lemma
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "IsOpen", "Set", "lebesgue_number_lemma" ]
Let `U : ι → Set α` be an open cover of a compact set `K`. Then there exists an entourage `V` such that for each `x ∈ K` its `V`-neighborhood is included in some `U i`. Moreover, one can choose an entourage from a given basis.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.lebesgue_number_lemma_nhds' {ι' : Sort*} {p : ι' → Prop} {V : ι' → Set (α × α)} {U : (x : α) → x ∈ K → Set α} (hbasis : (𝓤 α).HasBasis p V) (hK : IsCompact K) (hU : ∀ x hx, U x hx ∈ 𝓝 x) : ∃ i, p i ∧ ∀ x ∈ K, ∃ y : K, ball x (V i) ⊆ U y y.2
by refine (hbasis.exists_iff ?_).1 (lebesgue_number_lemma_nhds' hK hU) exact fun s t hst ht x hx ↦ (ht x hx).imp fun y hy ↦ Subset.trans (ball_mono hst _) hy
theorem
Filter.HasBasis.lebesgue_number_lemma_nhds'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "lebesgue_number_lemma_nhds'" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.lebesgue_number_lemma_nhds {ι' : Sort*} {p : ι' → Prop} {V : ι' → Set (α × α)} {U : α → Set α} (hbasis : (𝓤 α).HasBasis p V) (hK : IsCompact K) (hU : ∀ x ∈ K, U x ∈ 𝓝 x) : ∃ i, p i ∧ ∀ x ∈ K, ∃ y, ball x (V i) ⊆ U y
by refine (hbasis.exists_iff ?_).1 (lebesgue_number_lemma_nhds hK hU) exact fun s t hst ht x hx ↦ (ht x hx).imp fun y hy ↦ Subset.trans (ball_mono hst _) hy
theorem
Filter.HasBasis.lebesgue_number_lemma_nhds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "lebesgue_number_lemma_nhds" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.lebesgue_number_lemma_nhdsWithin' {ι' : Sort*} {p : ι' → Prop} {V : ι' → Set (α × α)} {U : (x : α) → x ∈ K → Set α} (hbasis : (𝓤 α).HasBasis p V) (hK : IsCompact K) (hU : ∀ x hx, U x hx ∈ 𝓝[K] x) : ∃ i, p i ∧ ∀ x ∈ K, ∃ y : K, ball x (V i) ∩ K ⊆ U y y.2
by refine (hbasis.exists_iff ?_).1 (lebesgue_number_lemma_nhdsWithin' hK hU) exact fun s t hst ht x hx ↦ (ht x hx).imp fun y hy ↦ Subset.trans (Set.inter_subset_inter_left K (ball_mono hst _)) hy
theorem
Filter.HasBasis.lebesgue_number_lemma_nhdsWithin'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "Set.inter_subset_inter_left", "lebesgue_number_lemma_nhdsWithin'" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.lebesgue_number_lemma_nhdsWithin {ι' : Sort*} {p : ι' → Prop} {V : ι' → Set (α × α)} {U : α → Set α} (hbasis : (𝓤 α).HasBasis p V) (hK : IsCompact K) (hU : ∀ x ∈ K, U x ∈ 𝓝[K] x) : ∃ i, p i ∧ ∀ x ∈ K, ∃ y, ball x (V i) ∩ K ⊆ U y
by refine (hbasis.exists_iff ?_).1 (lebesgue_number_lemma_nhdsWithin hK hU) exact fun s t hst ht x hx ↦ (ht x hx).imp fun y hy ↦ Subset.trans (Set.inter_subset_inter_left K (ball_mono hst _)) hy
theorem
Filter.HasBasis.lebesgue_number_lemma_nhdsWithin
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "Set.inter_subset_inter_left", "lebesgue_number_lemma_nhdsWithin" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
lebesgue_number_lemma_sUnion {S : Set (Set α)} (hK : IsCompact K) (hopen : ∀ s ∈ S, IsOpen s) (hcover : K ⊆ ⋃₀ S) : ∃ V ∈ 𝓤 α, ∀ x ∈ K, ∃ s ∈ S, ball x V ⊆ s
by rw [sUnion_eq_iUnion] at hcover simpa using lebesgue_number_lemma hK (by simpa) hcover
theorem
lebesgue_number_lemma_sUnion
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "IsOpen", "Set", "lebesgue_number_lemma" ]
Let `c : Set (Set α)` be an open cover of a compact set `s`. Then there exists an entourage `n` such that for each `x ∈ s` its `n`-neighborhood is contained in some `t ∈ c`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsCompact.nhdsSet_basis_uniformity {p : ι → Prop} {V : ι → Set (α × α)} (hbasis : (𝓤 α).HasBasis p V) (hK : IsCompact K) : (𝓝ˢ K).HasBasis p fun i => ⋃ x ∈ K, ball x (V i)
where mem_iff' U := by constructor · intro H have HKU : K ⊆ ⋃ _ : Unit, interior U := by simpa only [iUnion_const, subset_interior_iff_mem_nhdsSet] using H obtain ⟨i, hpi, hi⟩ : ∃ i, p i ∧ ⋃ x ∈ K, ball x (V i) ⊆ interior U := by simpa using hbasis.lebesgue_number_lemma hK (fun _ ↦...
theorem
IsCompact.nhdsSet_basis_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "Set", "bUnion_mem_nhdsSet", "interior", "isOpen_interior", "subset_interior_iff_mem_nhdsSet" ]
If `K` is a compact set in a uniform space and `{V i | p i}` is a basis of entourages, then `{⋃ x ∈ K, UniformSpace.ball x (V i) | p i}` is a basis of `𝓝ˢ K`. Here "`{s i | p i}` is a basis of a filter `l`" means `Filter.HasBasis l p s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Disjoint.exists_uniform_thickening {A B : Set α} (hA : IsCompact A) (hB : IsClosed B) (h : Disjoint A B) : ∃ V ∈ 𝓤 α, Disjoint (⋃ x ∈ A, ball x V) (⋃ x ∈ B, ball x V)
by have : Bᶜ ∈ 𝓝ˢ A := hB.isOpen_compl.mem_nhdsSet.mpr h.le_compl_right rw [(hA.nhdsSet_basis_uniformity (Filter.basis_sets _)).mem_iff] at this rcases this with ⟨U, hU, hUAB⟩ rcases comp_symm_mem_uniformity_sets hU with ⟨V, hV, hVsymm, hVU⟩ refine ⟨V, hV, Set.disjoint_left.mpr fun x => ?_⟩ simp only [mem_...
theorem
Disjoint.exists_uniform_thickening
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "Disjoint", "Filter.basis_sets", "IsClosed", "IsCompact", "Set", "comp_symm_mem_uniformity_sets" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Disjoint.exists_uniform_thickening_of_basis {p : ι → Prop} {s : ι → Set (α × α)} (hU : (𝓤 α).HasBasis p s) {A B : Set α} (hA : IsCompact A) (hB : IsClosed B) (h : Disjoint A B) : ∃ i, p i ∧ Disjoint (⋃ x ∈ A, ball x (s i)) (⋃ x ∈ B, ball x (s i))
by rcases h.exists_uniform_thickening hA hB with ⟨V, hV, hVAB⟩ rcases hU.mem_iff.1 hV with ⟨i, hi, hiV⟩ exact ⟨i, hi, hVAB.mono (iUnion₂_mono fun a _ => ball_mono hiV a) (iUnion₂_mono fun b _ => ball_mono hiV b)⟩
theorem
Disjoint.exists_uniform_thickening_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "Disjoint", "IsClosed", "IsCompact", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
lebesgue_number_of_compact_open {K U : Set α} (hK : IsCompact K) (hU : IsOpen U) (hKU : K ⊆ U) : ∃ V ∈ 𝓤 α, IsOpen V ∧ ∀ x ∈ K, UniformSpace.ball x V ⊆ U
let ⟨V, ⟨hV, hVo⟩, hVU⟩ := (hK.nhdsSet_basis_uniformity uniformity_hasBasis_open).mem_iff.1 (hU.mem_nhdsSet.2 hKU) ⟨V, hV, hVo, iUnion₂_subset_iff.1 hVU⟩
theorem
lebesgue_number_of_compact_open
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsCompact", "IsOpen", "Set", "UniformSpace.ball", "uniformity_hasBasis_open" ]
A useful consequence of the Lebesgue number lemma: given any compact set `K` contained in an open set `U`, we can find an (open) entourage `V` such that the ball of size `V` about any point of `K` is contained in `U`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
nhdsSet_diagonal_eq_uniformity [CompactSpace α] : 𝓝ˢ (diagonal α) = 𝓤 α
by refine nhdsSet_diagonal_le_uniformity.antisymm ?_ have : (𝓤 (α × α)).HasBasis (fun U => U ∈ 𝓤 α) fun U => (fun p : (α × α) × α × α => ((p.1.1, p.2.1), p.1.2, p.2.2)) ⁻¹' U ×ˢ U := by rw [uniformity_prod_eq_comap_prod] exact (𝓤 α).basis_sets.prod_self.comap _ refine (isCompact_diagonal.nhds...
theorem
nhdsSet_diagonal_eq_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "CompactSpace", "refl_mem_uniformity", "uniformity_prod_eq_comap_prod" ]
On a compact uniform space, the topology determines the uniform structure, entourages are exactly the neighborhoods of the diagonal.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
compactSpace_uniformity [CompactSpace α] : 𝓤 α = ⨆ x, 𝓝 (x, x)
nhdsSet_diagonal_eq_uniformity.symm.trans (nhdsSet_diagonal _)
theorem
compactSpace_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "CompactSpace", "nhdsSet_diagonal" ]
On a compact uniform space, the topology determines the uniform structure, entourages are exactly the neighborhoods of the diagonal.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
unique_uniformity_of_compact [t : TopologicalSpace γ] [CompactSpace γ] {u u' : UniformSpace γ} (h : u.toTopologicalSpace = t) (h' : u'.toTopologicalSpace = t) : u = u'
by refine UniformSpace.ext ?_ have : @CompactSpace γ u.toTopologicalSpace := by rwa [h] have : @CompactSpace γ u'.toTopologicalSpace := by rwa [h'] rw [@compactSpace_uniformity _ u, compactSpace_uniformity, h, h']
theorem
unique_uniformity_of_compact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "CompactSpace", "TopologicalSpace", "UniformSpace", "UniformSpace.ext", "compactSpace_uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.relPreimage_of_isCompact [TopologicalSpace α] [TopologicalSpace β] {s : SetRel α β} (hs : IsClosed s) {t : Set β} (ht : IsCompact t) : IsClosed (s.preimage t)
by rw [← isOpen_compl_iff, isOpen_iff_eventually] at hs ⊢ simp_rw [Set.mem_compl_iff, SetRel.mem_preimage, not_exists, not_and] exact fun y hy => ht.eventually_forall_of_forall_eventually fun x hx => hs _ <| hy _ hx
theorem
IsClosed.relPreimage_of_isCompact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsClosed", "IsCompact", "Set", "Set.mem_compl_iff", "SetRel", "SetRel.mem_preimage", "TopologicalSpace", "isOpen_compl_iff", "isOpen_iff_eventually" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.relImage_of_isCompact [TopologicalSpace α] [TopologicalSpace β] {s : SetRel α β} (hs : IsClosed s) {t : Set α} (ht : IsCompact t) : IsClosed (s.image t)
hs.relInv.relPreimage_of_isCompact ht
theorem
IsClosed.relImage_of_isCompact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Compact.lean
[]
[ "IsClosed", "IsCompact", "Set", "SetRel", "TopologicalSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendsto_iff_forall_isCompact_tendstoUniformlyOn {ι : Type u₃} {p : Filter ι} {F : ι → C(α, β)} {f} : Tendsto F p (𝓝 f) ↔ ∀ K, IsCompact K → TendstoUniformlyOn (fun i a => F i a) f p K
by rw [tendsto_nhds_compactOpen] constructor · -- Let us prove that convergence in the compact-open topology -- implies uniform convergence on compacts. -- Consider a compact set `K` intro h K hK -- Since `K` is compact, it suffices to prove locally uniform convergence rw [← tendstoLocallyUnif...
theorem
ContinuousMap.tendsto_iff_forall_isCompact_tendstoUniformlyOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "Filter", "IsCompact", "SetRel.symm", "TendstoUniformlyOn", "comp_open_symm_mem_uniformity_sets", "inter_mem_nhdsWithin", "lebesgue_number_of_compact_open", "mem_uniformity_isClosed", "tendstoLocallyUniformlyOn_iff_tendstoUniformlyOn_of_compact" ]
Compact-open topology on `C(α, β)` agrees with the topology of uniform convergence on compacts: a family of continuous functions `F i` tends to `f` in the compact-open topology if and only if the `F i` tends to `f` uniformly on all compact sets.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
toUniformOnFunIsCompact (f : C(α, β)) : α →ᵤ[{K | IsCompact K}] β
UniformOnFun.ofFun {K | IsCompact K} f
def
ContinuousMap.toUniformOnFunIsCompact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "IsCompact", "UniformOnFun.ofFun" ]
Interpret a bundled continuous map as an element of `α →ᵤ[{K | IsCompact K}] β`. We use this map to induce the `UniformSpace` structure on `C(α, β)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
toUniformOnFun_toFun (f : C(α, β)) : UniformOnFun.toFun _ f.toUniformOnFunIsCompact = f
rfl
theorem
ContinuousMap.toUniformOnFun_toFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "UniformOnFun.toFun" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
range_toUniformOnFunIsCompact : range (toUniformOnFunIsCompact) = {f : UniformOnFun α β {K | IsCompact K} | Continuous f}
Set.ext fun f ↦ ⟨fun g ↦ g.choose_spec ▸ g.choose.2, fun hf ↦ ⟨⟨f, hf⟩, rfl⟩⟩
theorem
ContinuousMap.range_toUniformOnFunIsCompact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "Continuous", "IsCompact", "Set.ext", "UniformOnFun" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
compactConvergenceUniformSpace : UniformSpace C(α, β)
.replaceTopology (.comap toUniformOnFunIsCompact inferInstance) <| by refine TopologicalSpace.ext_nhds fun f ↦ eq_of_forall_le_iff fun l ↦ ?_ simp_rw [← tendsto_id', tendsto_iff_forall_isCompact_tendstoUniformlyOn, nhds_induced, tendsto_comap_iff, UniformOnFun.tendsto_iff_tendstoUniformlyOn] rfl
instance
ContinuousMap.compactConvergenceUniformSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "UniformOnFun.tendsto_iff_tendstoUniformlyOn", "UniformSpace", "comap", "eq_of_forall_le_iff", "nhds_induced" ]
Uniform space structure on `C(α, β)`. The uniformity comes from `α →ᵤ[{K | IsCompact K}] β` (i.e., `UniformOnFun α β {K | IsCompact K}`) which defines topology of uniform convergence on compact sets. We use `ContinuousMap.tendsto_iff_forall_isCompact_tendstoUniformlyOn` to show that the induced topology agrees with th...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformEmbedding_toUniformOnFunIsCompact : IsUniformEmbedding (toUniformOnFunIsCompact : C(α, β) → α →ᵤ[{K | IsCompact K}] β)
where comap_uniformity := rfl injective := DFunLike.coe_injective
theorem
ContinuousMap.isUniformEmbedding_toUniformOnFunIsCompact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "DFunLike.coe_injective", "IsCompact", "IsUniformEmbedding" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
continuous_iff_continuous_uniformOnFun {X : Type*} [TopologicalSpace X] (f : X → C(α, β)) : Continuous f ↔ Continuous (fun x ↦ ofFun {K | IsCompact K} (f x))
isUniformEmbedding_toUniformOnFunIsCompact.isInducing.continuous_iff
theorem
ContinuousMap.continuous_iff_continuous_uniformOnFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "Continuous", "IsCompact", "TopologicalSpace" ]
`f : X → C(α, β)` is continuous if any only if it is continuous when reinterpreted as a map `f : X → α →ᵤ[{K | IsCompact K}] β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.Filter.HasBasis.compactConvergenceUniformity {ι : Type*} {pi : ι → Prop} {s : ι → Set (β × β)} (h : (𝓤 β).HasBasis pi s) : HasBasis (𝓤 C(α, β)) (fun p : Set α × ι => IsCompact p.1 ∧ pi p.2) fun p => { fg : C(α, β) × C(α, β) | ∀ x ∈ p.1, (fg.1 x, fg.2 x) ∈ s p.2 }
by rw [← isUniformEmbedding_toUniformOnFunIsCompact.comap_uniformity] exact .comap _ <| UniformOnFun.hasBasis_uniformity_of_basis _ _ {K | IsCompact K} ⟨∅, isCompact_empty⟩ (directedOn_of_sup_mem fun _ _ ↦ IsCompact.union) h
theorem
Filter.HasBasis.compactConvergenceUniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "IsCompact", "IsCompact.union", "Set", "UniformOnFun.hasBasis_uniformity_of_basis", "comap", "directedOn_of_sup_mem" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_compactConvergenceUniformity : HasBasis (𝓤 C(α, β)) (fun p : Set α × Set (β × β) => IsCompact p.1 ∧ p.2 ∈ 𝓤 β) fun p => { fg : C(α, β) × C(α, β) | ∀ x ∈ p.1, (fg.1 x, fg.2 x) ∈ p.2 }
(basis_sets _).compactConvergenceUniformity
theorem
ContinuousMap.hasBasis_compactConvergenceUniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "IsCompact", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
mem_compactConvergence_entourage_iff (X : Set (C(α, β) × C(α, β))) : X ∈ 𝓤 C(α, β) ↔ ∃ (K : Set α) (V : Set (β × β)), IsCompact K ∧ V ∈ 𝓤 β ∧ { fg : C(α, β) × C(α, β) | ∀ x ∈ K, (fg.1 x, fg.2 x) ∈ V } ⊆ X
by simp [hasBasis_compactConvergenceUniformity.mem_iff, and_assoc]
theorem
ContinuousMap.mem_compactConvergence_entourage_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "IsCompact", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.CompactExhaustion.hasBasis_compactConvergenceUniformity {ι : Type*} {p : ι → Prop} {V : ι → Set (β × β)} (K : CompactExhaustion α) (hb : (𝓤 β).HasBasis p V) : HasBasis (𝓤 C(α, β)) (fun i : ℕ × ι ↦ p i.2) fun i ↦ {fg | ∀ x ∈ K i.1, (fg.1 x, fg.2 x) ∈ V i.2}
(UniformOnFun.hasBasis_uniformity_of_covering_of_basis {K | IsCompact K} K.isCompact (Monotone.directed_le K.subset) (fun _ ↦ K.exists_superset_of_isCompact) hb).comap _
theorem
CompactExhaustion.hasBasis_compactConvergenceUniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "CompactExhaustion", "IsCompact", "Monotone.directed_le", "Set", "UniformOnFun.hasBasis_uniformity_of_covering_of_basis", "comap" ]
If `K` is a compact exhaustion of `α` and `V i` bounded by `p i` is a basis of entourages of `β`, then `fun (n, i) ↦ {(f, g) | ∀ x ∈ K n, (f x, g x) ∈ V i}` bounded by `p i` is a basis of entourages of `C(α, β)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.CompactExhaustion.hasAntitoneBasis_compactConvergenceUniformity {V : ℕ → Set (β × β)} (K : CompactExhaustion α) (hb : (𝓤 β).HasAntitoneBasis V) : HasAntitoneBasis (𝓤 C(α, β)) fun n ↦ {fg | ∀ x ∈ K n, (fg.1 x, fg.2 x) ∈ V n}
(UniformOnFun.hasAntitoneBasis_uniformity {K | IsCompact K} K.isCompact K.subset (fun _ ↦ K.exists_superset_of_isCompact) hb).comap _
theorem
CompactExhaustion.hasAntitoneBasis_compactConvergenceUniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "CompactExhaustion", "IsCompact", "Set", "UniformOnFun.hasAntitoneBasis_uniformity", "comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendsto_of_tendstoLocallyUniformly (h : TendstoLocallyUniformly (fun i a => F i a) f p) : Tendsto F p (𝓝 f)
by rw [tendsto_iff_forall_isCompact_tendstoUniformlyOn] intro K hK rw [← tendstoLocallyUniformlyOn_iff_tendstoUniformlyOn_of_compact hK] exact h.tendstoLocallyUniformlyOn
theorem
ContinuousMap.tendsto_of_tendstoLocallyUniformly
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "TendstoLocallyUniformly", "tendstoLocallyUniformlyOn_iff_tendstoUniformlyOn_of_compact" ]
Locally uniform convergence implies convergence in the compact-open topology.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendsto_iff_tendstoLocallyUniformly [WeaklyLocallyCompactSpace α] : Tendsto F p (𝓝 f) ↔ TendstoLocallyUniformly (fun i a => F i a) f p
by refine ⟨fun h V hV x ↦ ?_, tendsto_of_tendstoLocallyUniformly⟩ rw [tendsto_iff_forall_isCompact_tendstoUniformlyOn] at h obtain ⟨n, hn₁, hn₂⟩ := exists_compact_mem_nhds x exact ⟨n, hn₂, h n hn₁ V hV⟩
theorem
ContinuousMap.tendsto_iff_tendstoLocallyUniformly
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "TendstoLocallyUniformly", "WeaklyLocallyCompactSpace" ]
In a weakly locally compact space, convergence in the compact-open topology is the same as locally uniform convergence. The right-to-left implication holds in any topological space, see `ContinuousMap.tendsto_of_tendstoLocallyUniformly`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_comp (g : C(β, δ)) (hg : UniformContinuous g) : UniformContinuous (ContinuousMap.comp g : C(α, β) → C(α, δ))
isUniformEmbedding_toUniformOnFunIsCompact.uniformContinuous_iff.mpr <| UniformOnFun.postcomp_uniformContinuous hg |>.comp isUniformEmbedding_toUniformOnFunIsCompact.uniformContinuous
theorem
ContinuousMap.uniformContinuous_comp
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "ContinuousMap.comp", "UniformContinuous", "UniformOnFun.postcomp_uniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformInducing_comp (g : C(β, δ)) (hg : IsUniformInducing g) : IsUniformInducing (ContinuousMap.comp g : C(α, β) → C(α, δ))
isUniformEmbedding_toUniformOnFunIsCompact.isUniformInducing.of_comp_iff.mp <| UniformOnFun.postcomp_isUniformInducing hg |>.comp isUniformEmbedding_toUniformOnFunIsCompact.isUniformInducing
theorem
ContinuousMap.isUniformInducing_comp
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "ContinuousMap.comp", "IsUniformInducing", "UniformOnFun.postcomp_isUniformInducing" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformEmbedding_comp (g : C(β, δ)) (hg : IsUniformEmbedding g) : IsUniformEmbedding (ContinuousMap.comp g : C(α, β) → C(α, δ))
isUniformEmbedding_toUniformOnFunIsCompact.of_comp_iff.mp <| UniformOnFun.postcomp_isUniformEmbedding hg |>.comp isUniformEmbedding_toUniformOnFunIsCompact
theorem
ContinuousMap.isUniformEmbedding_comp
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "ContinuousMap.comp", "IsUniformEmbedding", "UniformOnFun.postcomp_isUniformEmbedding" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_comp_left (g : C(α, γ)) : UniformContinuous (fun f ↦ f.comp g : C(γ, β) → C(α, β))
isUniformEmbedding_toUniformOnFunIsCompact.uniformContinuous_iff.mpr <| UniformOnFun.precomp_uniformContinuous (fun _ hK ↦ hK.image g.continuous) |>.comp isUniformEmbedding_toUniformOnFunIsCompact.uniformContinuous
theorem
ContinuousMap.uniformContinuous_comp_left
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "UniformContinuous", "UniformOnFun.precomp_uniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.UniformEquiv.arrowCongr (φ : α ≃ₜ γ) (ψ : β ≃ᵤ δ) : C(α, β) ≃ᵤ C(γ, δ)
where toFun f := .comp ψ.toHomeomorph <| f.comp φ.symm invFun f := .comp ψ.symm.toHomeomorph <| f.comp φ left_inv f := ext fun _ ↦ ψ.left_inv (f _) |>.trans <| congrArg f <| φ.left_inv _ right_inv f := ext fun _ ↦ ψ.right_inv (f _) |>.trans <| congrArg f <| φ.right_inv _ uniformContinuous_toFun := uniformCont...
def
UniformEquiv.arrowCongr
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "trans" ]
Any pair of a homeomorphism `X ≃ₜ Z` and an isomorphism `Y ≃ᵤ T` of uniform spaces gives rise to an isomorphism `C(X, Y) ≃ᵤ C(Z, T)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_compactConvergenceUniformity_of_compact : HasBasis (𝓤 C(α, β)) (fun V : Set (β × β) => V ∈ 𝓤 β) fun V ↦ {fg : C(α, β) × C(α, β) | ∀ x, (fg.1 x, fg.2 x) ∈ V}
hasBasis_compactConvergenceUniformity.to_hasBasis (fun p hp => ⟨p.2, hp.2, fun _fg hfg x _hx => hfg x⟩) fun V hV ↦ ⟨⟨univ, V⟩, ⟨isCompact_univ, hV⟩, fun _fg hfg x => hfg x (mem_univ x)⟩
theorem
ContinuousMap.hasBasis_compactConvergenceUniformity_of_compact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.Filter.HasBasis.compactConvergenceUniformity_of_compact {ι : Sort*} {p : ι → Prop} {V : ι → Set (β × β)} (h : (𝓤 β).HasBasis p V) : HasBasis (𝓤 C(α, β)) p fun i ↦ {fg : C(α, β) × C(α, β) | ∀ x, (fg.1 x, fg.2 x) ∈ V i}
hasBasis_compactConvergenceUniformity_of_compact.to_hasBasis (fun _U hU ↦ (h.mem_iff.mp hU).imp fun _i ⟨hpi, hi⟩ ↦ ⟨hpi, fun _ h a ↦ hi <| h a⟩) fun i hi ↦ ⟨V i, h.mem_of_mem hi, .rfl⟩
theorem
Filter.HasBasis.compactConvergenceUniformity_of_compact
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformEmbedding_uniformFunOfFun : IsUniformEmbedding ((ofFun ·) : C(α, β) → α →ᵤ β)
where comap_uniformity := UniformOnFun.uniformEquivUniformFun β _ isCompact_univ |>.isUniformEmbedding.comp isUniformEmbedding_toUniformOnFunIsCompact |>.comap_uniformity injective := DFunLike.coe_injective
theorem
ContinuousMap.isUniformEmbedding_uniformFunOfFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "DFunLike.coe_injective", "IsUniformEmbedding", "UniformOnFun.uniformEquivUniformFun", "isCompact_univ" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendsto_iff_tendstoUniformly : Tendsto F p (𝓝 f) ↔ TendstoUniformly (fun i a => F i a) f p
by simp [isUniformEmbedding_uniformFunOfFun.isInducing.tendsto_nhds_iff, UniformFun.tendsto_iff_tendstoUniformly, Function.comp_def]
theorem
ContinuousMap.tendsto_iff_tendstoUniformly
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "TendstoUniformly", "UniformFun.tendsto_iff_tendstoUniformly" ]
Convergence in the compact-open topology is the same as uniform convergence for sequences of continuous functions on a compact space.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
continuous_iff_continuous_uniformFun {X : Type*} [TopologicalSpace X] (f : X → C(α, β)) : Continuous f ↔ Continuous (fun x ↦ ofFun (f x))
isUniformEmbedding_uniformFunOfFun.isInducing.continuous_iff
theorem
ContinuousMap.continuous_iff_continuous_uniformFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "Continuous", "TopologicalSpace" ]
When `α` is compact, `f : X → C(α, β)` is continuous if any only if it is continuous when reinterpreted as a map `f : X → α →ᵤ β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.ContinuousOn.tendsto_restrict_iff_tendstoUniformlyOn {s : Set α} [CompactSpace s] {f : α → β} (hf : ContinuousOn f s) {ι : Type*} {p : Filter ι} {F : ι → α → β} (hF : ∀ i, ContinuousOn (F i) s) : Tendsto (fun i ↦ ⟨_, (hF i).restrict⟩ : ι → C(s, β)) p (𝓝 ⟨_, hf.restrict⟩) ↔ TendstoUniformlyOn F...
by rw [ContinuousMap.tendsto_iff_tendstoUniformly, tendstoUniformlyOn_iff_tendstoUniformly_comp_coe] congr!
theorem
ContinuousOn.tendsto_restrict_iff_tendstoUniformlyOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "CompactSpace", "ContinuousMap.tendsto_iff_tendstoUniformly", "ContinuousOn", "Filter", "Set", "TendstoUniformlyOn", "tendstoUniformlyOn_iff_tendstoUniformly_comp_coe" ]
Given functions `F i, f` which are continuous on a compact set `s`, `F` tends to `f` uniformly on `s` if and only if the restrictions (as elements of `C(s, β)`) converge.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
_root_.ContinuousOn.continuous_restrict_iff_continuous_uniformOnFun {X : Type*} [TopologicalSpace X] {f : X → α → β} {s : Set α} (hf : ∀ x, ContinuousOn (f x) s) [CompactSpace s] : Continuous (fun x ↦ ⟨_, (hf x).restrict⟩ : X → C(s, β)) ↔ Continuous (fun x ↦ ofFun {s} (f x))
by rw [ContinuousMap.continuous_iff_continuous_uniformFun, UniformOnFun.continuous_rng_iff] simp [Function.comp_def]
theorem
ContinuousOn.continuous_restrict_iff_continuous_uniformOnFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "CompactSpace", "Continuous", "ContinuousMap.continuous_iff_continuous_uniformFun", "ContinuousOn", "Set", "TopologicalSpace", "UniformOnFun.continuous_rng_iff" ]
A family `f : X → α → β`, each of which is continuous on a compact set `s : Set α` is continuous in the topology `X → α →ᵤ[{s}] β` if and only if the family of continuous restrictions `X → C(s, β)` is continuous.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformSpace_eq_inf_precomp_of_cover {δ₁ δ₂ : Type*} [TopologicalSpace δ₁] [TopologicalSpace δ₂] (φ₁ : C(δ₁, α)) (φ₂ : C(δ₂, α)) (h_proper₁ : IsProperMap φ₁) (h_proper₂ : IsProperMap φ₂) (h_cover : range φ₁ ∪ range φ₂ = univ) : ((inferInstance : UniformSpace C(α, β))) = .comap (comp · φ₁) inferInstanc...
by -- We check the analogous result for `UniformOnFun` using -- `UniformOnFun.uniformSpace_eq_inf_precomp_of_cover`... set 𝔖 : Set (Set α) := {K | IsCompact K} set 𝔗₁ : Set (Set δ₁) := {K | IsCompact K} set 𝔗₂ : Set (Set δ₂) := {K | IsCompact K} have h_image₁ : MapsTo (φ₁ '' ·) 𝔗₁ 𝔖 := fun K hK ↦ hK.im...
theorem
ContinuousMap.uniformSpace_eq_inf_precomp_of_cover
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "IsCompact", "IsProperMap", "Set", "TopologicalSpace", "UniformOnFun.uniformSpace_eq_inf_precomp_of_cover", "UniformSpace", "UniformSpace.comap_comap", "UniformSpace.comap_inf", "comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformSpace_eq_iInf_precomp_of_cover {δ : ι → Type*} [∀ i, TopologicalSpace (δ i)] (φ : Π i, C(δ i, α)) (h_proper : ∀ i, IsProperMap (φ i)) (h_lf : LocallyFinite fun i ↦ range (φ i)) (h_cover : ⋃ i, range (φ i) = univ) : ((inferInstance : UniformSpace C(α, β))) = ⨅ i, .comap (comp · (φ i)) inferInstance
by -- We check the analogous result for `UniformOnFun` using -- `UniformOnFun.uniformSpace_eq_iInf_precomp_of_cover`... set 𝔖 : Set (Set α) := {K | IsCompact K} set 𝔗 : Π i, Set (Set (δ i)) := fun i ↦ {K | IsCompact K} have h_image : ∀ i, MapsTo (φ i '' ·) (𝔗 i) 𝔖 := fun i K hK ↦ hK.image (φ i).continuous...
theorem
ContinuousMap.uniformSpace_eq_iInf_precomp_of_cover
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "IsCompact", "IsProperMap", "LocallyFinite", "Set", "TopologicalSpace", "UniformOnFun.uniformSpace_eq_iInf_precomp_of_cover", "UniformSpace", "UniformSpace.comap_comap", "UniformSpace.comap_iInf", "comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
instCompleteSpaceOfCompactlyCoherentSpace [CompactlyCoherentSpace α] : CompleteSpace C(α, β)
by rw [completeSpace_iff_isComplete_range isUniformEmbedding_toUniformOnFunIsCompact.isUniformInducing, range_toUniformOnFunIsCompact, ← completeSpace_coe_iff_isComplete] exact (UniformOnFun.isClosed_setOf_continuous CompactlyCoherentSpace.isCoherentWith).completeSpace_coe
instance
ContinuousMap.instCompleteSpaceOfCompactlyCoherentSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "CompactlyCoherentSpace", "CompleteSpace", "UniformOnFun.isClosed_setOf_continuous", "completeSpace_coe_iff_isComplete", "completeSpace_iff_isComplete_range" ]
If the topology on `α` is generated by its restrictions to compact sets, then the space of continuous maps `C(α, β)` is complete (w.r.t. the compact convergence uniformity). Sufficient conditions on `α` to satisfy this condition are (weak) local compactness and sequential compactness.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isComplete_setOf_eqOn [CompleteSpace C(α, β)] (f : α → β) (s : Set α) : IsComplete {g : C(α, β) | EqOn g f s}
by classical intro l hlc hlf rcases CompleteSpace.complete hlc with ⟨f', hf'⟩ have := hlc.1 have H₁ : ∀ x ∈ s, Inseparable (f x) (f' x) := fun x hx ↦ by refine tendsto_nhds_unique_inseparable ?_ ((continuous_eval_const x).continuousAt.mono_left hf') refine tendsto_const_nhds.congr' <| .filter_mono ?_ ...
theorem
ContinuousMap.isComplete_setOf_eqOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompactConvergence.lean
[]
[ "CompleteSpace", "Inseparable", "Inseparable.refl", "IsComplete", "Set", "Set.piecewise_eqOn", "by_cases", "continuous_congr_of_inseparable", "inseparable_pi", "symm", "tendsto_nhds_unique_inseparable" ]
If `C(α, β)` is a complete space, then for any (possibly, discontinuous) function `f` and any set `s`, the set of functions `g : C(α, β)` that are equal to `f` on `s` is a complete set. Note that this set does not have to be a closed set when `β` is not T0. This lemma is useful to prove that, e.g., the space of paths ...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Rat.uniformSpace_eq : (AbsoluteValue.abs : AbsoluteValue ℚ ℚ).uniformSpace = PseudoMetricSpace.toUniformSpace
by ext s rw [(AbsoluteValue.hasBasis_uniformity _).mem_iff, Metric.uniformity_basis_dist_rat.mem_iff] simp only [Rat.dist_eq, AbsoluteValue.abs_apply, ← Rat.cast_sub, ← Rat.cast_abs, Rat.cast_lt, _root_.abs_sub_comm]
theorem
Rat.uniformSpace_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "AbsoluteValue", "AbsoluteValue.abs", "AbsoluteValue.hasBasis_uniformity", "Rat.cast_abs", "Rat.cast_lt", "Rat.cast_sub", "Rat.dist_eq" ]
The metric space uniform structure on ℚ (which presupposes the existence of real numbers) agrees with the one coming directly from (abs : ℚ → ℚ).
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
rationalCauSeqPkg : @AbstractCompletion ℚ <| (@AbsoluteValue.abs ℚ _).uniformSpace
@AbstractCompletion.mk (space := ℝ) (coe := ((↑) : ℚ → ℝ)) (uniformStruct := by infer_instance) (complete := by infer_instance) (separation := by infer_instance) (isUniformInducing := by rw [Rat.uniformSpace_eq] exact Rat.isUniformEmbedding_coe_real.isUniformInducing) (dense := R...
def
rationalCauSeqPkg
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "AbsoluteValue.abs", "Rat.uniformSpace_eq" ]
Cauchy reals packaged as a completion of ℚ using the absolute value route.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Q
ℚ deriving CommRing, Inhabited
def
CompareReals.Q
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "CommRing" ]
Type wrapper around ℚ to make sure the absolute value uniform space instance is picked up instead of the metric space one. We proved in `Rat.uniformSpace_eq` that they are equal, but they are not definitionaly equal, so it would confuse the type class system (and probably also human readers).
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformSpace : UniformSpace Q
fast_instance% (@AbsoluteValue.abs ℚ _).uniformSpace
instance
CompareReals.uniformSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "AbsoluteValue.abs", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Bourbakiℝ : Type
Completion Q deriving Inhabited
def
CompareReals.Bourbakiℝ
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[]
Real numbers constructed as in Bourbaki.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Bourbaki.uniformSpace : UniformSpace Bourbakiℝ
fast_instance% Completion.uniformSpace Q
instance
CompareReals.Bourbaki.uniformSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
bourbakiPkg : AbstractCompletion Q
Completion.cPkg
def
CompareReals.bourbakiPkg
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[]
Bourbaki reals packaged as a completion of Q using the general theory.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
compareEquiv : Bourbakiℝ ≃ᵤ ℝ
bourbakiPkg.compareEquiv rationalCauSeqPkg
def
CompareReals.compareEquiv
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "rationalCauSeqPkg" ]
The uniform bijection between Bourbaki and Cauchy reals.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
compare_uc : UniformContinuous compareEquiv
bourbakiPkg.uniformContinuous_compareEquiv rationalCauSeqPkg
theorem
CompareReals.compare_uc
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "UniformContinuous", "rationalCauSeqPkg" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
compare_uc_symm : UniformContinuous compareEquiv.symm
bourbakiPkg.uniformContinuous_compareEquiv_symm rationalCauSeqPkg
theorem
CompareReals.compare_uc_symm
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompareReals.lean
[]
[ "UniformContinuous", "rationalCauSeqPkg" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsComplete.isClosed [UniformSpace α] [T0Space α] {s : Set α} (h : IsComplete s) : IsClosed s
isClosed_iff_clusterPt.2 fun a ha => by let f := 𝓝[s] a have : Cauchy f := cauchy_nhds.mono' ha inf_le_left rcases h f this inf_le_right with ⟨y, ys, fy⟩ rwa [(tendsto_nhds_unique' ha inf_le_left fy : a = y)]
theorem
IsComplete.isClosed
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompleteSeparated.lean
[]
[ "Cauchy", "IsClosed", "IsComplete", "Set", "T0Space", "UniformSpace", "tendsto_nhds_unique'" ]
In a separated space, a complete set is closed.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsUniformEmbedding.isClosedEmbedding [UniformSpace α] [UniformSpace β] [CompleteSpace α] [T0Space β] {f : α → β} (hf : IsUniformEmbedding f) : IsClosedEmbedding f
⟨hf.isEmbedding, hf.isUniformInducing.isComplete_range.isClosed⟩
theorem
IsUniformEmbedding.isClosedEmbedding
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompleteSeparated.lean
[]
[ "CompleteSpace", "IsUniformEmbedding", "T0Space", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
continuous_extend_of_cauchy {e : α → β} {f : α → γ} (de : IsDenseInducing e) (h : ∀ b : β, Cauchy (map f (comap e <| 𝓝 b))) : Continuous (de.extend f)
de.continuous_extend fun b => CompleteSpace.complete (h b)
theorem
IsDenseInducing.continuous_extend_of_cauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/CompleteSeparated.lean
[]
[ "Cauchy", "Continuous", "IsDenseInducing", "comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchyFilter (α : Type u) [UniformSpace α] : Type u
{ f : Filter α // Cauchy f }
def
CauchyFilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "Cauchy", "Filter", "UniformSpace" ]
Space of Cauchy filters This is essentially the completion of a uniform space. The embeddings are the neighbourhood filters. This space is not minimal, the separated uniform space (i.e. quotiented on the intersection of all entourages) is necessary for this.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gen (s : SetRel α α) : SetRel (CauchyFilter α) (CauchyFilter α)
{ p | s ∈ p.1.val ×ˢ p.2.val }
def
CauchyFilter.gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "SetRel" ]
The pairs of Cauchy filters generated by a set.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
monotone_gen : Monotone (gen : SetRel α α → _)
monotone_setOf fun p => @Filter.monotone_mem _ (p.1.val ×ˢ p.2.val)
theorem
CauchyFilter.monotone_gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "Filter.monotone_mem", "Monotone", "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
symm_gen : map Prod.swap ((𝓤 α).lift' gen) ≤ (𝓤 α).lift' gen
by let f := fun s : SetRel α α => { p : CauchyFilter α × CauchyFilter α | s ∈ (p.2.val ×ˢ p.1.val : Filter (α × α)) } have h₁ : map Prod.swap ((𝓤 α).lift' gen) = (𝓤 α).lift' f := by delta gen simp [f, map_lift'_eq, monotone_setOf, Filter.monotone_mem, Function.comp_def, image_swap_eq_preimag...
theorem
CauchyFilter.symm_gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "Filter", "Filter.monotone_mem", "Filter.prod_comm", "SetRel", "le_rfl", "uniformity_lift_le_swap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
subset_gen_relComp {s t : SetRel α α} : gen s ○ gen t ⊆ gen (s ○ t)
fun ⟨f, g⟩ ⟨h, h₁, h₂⟩ => let ⟨t₁, (ht₁ : t₁ ∈ f.val), t₂, (ht₂ : t₂ ∈ h.val), (h₁ : t₁ ×ˢ t₂ ⊆ s)⟩ := mem_prod_iff.mp h₁ let ⟨t₃, (ht₃ : t₃ ∈ h.val), t₄, (ht₄ : t₄ ∈ g.val), (h₂ : t₃ ×ˢ t₄ ⊆ t)⟩ := mem_prod_iff.mp h₂ have : t₂ ∩ t₃ ∈ h.val := inter_mem ht₂ ht₃ let ⟨x, xt₂, xt₃⟩ := h.property.left.nonempty_of_m...
theorem
CauchyFilter.subset_gen_relComp
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
comp_gen : ((𝓤 α).lift' gen).lift' (fun s ↦ s ○ s) ≤ (𝓤 α).lift' gen
calc ((𝓤 α).lift' gen).lift' (fun s ↦ s ○ s) _ = (𝓤 α).lift' fun s ↦ gen s ○ gen s := by rw [lift'_lift'_assoc] · exact monotone_gen · exact monotone_id.relComp monotone_id _ ≤ (𝓤 α).lift' fun s ↦ gen <| s ○ s := lift'_mono' fun _ _hs => subset_gen_relComp _ = ((𝓤 α).lift' fun ...
theorem
CauchyFilter.comp_gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "SetRel", "comp_le_uniformity", "le_rfl", "monotone_id" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
mem_uniformity {s : Set (CauchyFilter α × CauchyFilter α)} : s ∈ 𝓤 (CauchyFilter α) ↔ ∃ t ∈ 𝓤 α, gen t ⊆ s
mem_lift'_sets monotone_gen
theorem
CauchyFilter.mem_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
basis_uniformity {ι : Sort*} {p : ι → Prop} {s : ι → SetRel α α} (h : (𝓤 α).HasBasis p s) : (𝓤 (CauchyFilter α)).HasBasis p (gen ∘ s)
h.lift' monotone_gen
theorem
CauchyFilter.basis_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
mem_uniformity' {s : Set (CauchyFilter α × CauchyFilter α)} : s ∈ 𝓤 (CauchyFilter α) ↔ ∃ t ∈ 𝓤 α, ∀ f g : CauchyFilter α, t ∈ f.1 ×ˢ g.1 → (f, g) ∈ s
by refine mem_uniformity.trans (exists_congr (fun t => and_congr_right_iff.mpr (fun _h => ?_))) exact ⟨fun h _f _g ht => h ht, fun h _p hp => h _ _ hp⟩
theorem
CauchyFilter.mem_uniformity'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
pureCauchy (a : α) : CauchyFilter α
⟨pure a, cauchy_pure⟩
def
CauchyFilter.pureCauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter" ]
Embedding of `α` into its completion `CauchyFilter α`
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformInducing_pureCauchy : IsUniformInducing (pureCauchy : α → CauchyFilter α)
⟨have : (preimage fun x : α × α => (pureCauchy x.fst, pureCauchy x.snd)) ∘ gen = id := funext fun s => Set.ext fun ⟨a₁, a₂⟩ => by simp [preimage, gen, pureCauchy] calc comap (fun x : α × α => (pureCauchy x.fst, pureCauchy x.snd)) ((𝓤 α).lift' gen) = (𝓤 α).lift' ((preimage fun x : α ×...
theorem
CauchyFilter.isUniformInducing_pureCauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "IsUniformInducing", "Set.ext", "comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformEmbedding_pureCauchy : IsUniformEmbedding (pureCauchy : α → CauchyFilter α)
where __ := isUniformInducing_pureCauchy injective _a₁ _a₂ h := pure_injective <| Subtype.ext_iff.1 h
theorem
CauchyFilter.isUniformEmbedding_pureCauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "IsUniformEmbedding" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
denseRange_pureCauchy : DenseRange (pureCauchy : α → CauchyFilter α)
fun f => by have h_ex : ∀ s ∈ 𝓤 (CauchyFilter α), ∃ y : α, (f, pureCauchy y) ∈ s := fun s hs => let ⟨t'', ht''₁, (ht''₂ : gen t'' ⊆ s)⟩ := (mem_lift'_sets monotone_gen).mp hs let ⟨t', ht'₁, ht'₂⟩ := comp_mem_uniformity_sets ht''₁ have : t' ∈ f.val ×ˢ f.val := f.property.right ht'₁ let ⟨t, ht, (h : t ...
theorem
CauchyFilter.denseRange_pureCauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "ClusterPt", "DenseRange", "Set.inter_comm", "SetRel.prodMk_mem_comp", "closure_eq_cluster_pts", "comp_mem_uniformity_sets", "nhds_eq_uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isDenseInducing_pureCauchy : IsDenseInducing (pureCauchy : α → CauchyFilter α)
isUniformInducing_pureCauchy.isDenseInducing denseRange_pureCauchy
theorem
CauchyFilter.isDenseInducing_pureCauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "IsDenseInducing" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isDenseEmbedding_pureCauchy : IsDenseEmbedding (pureCauchy : α → CauchyFilter α)
isUniformEmbedding_pureCauchy.isDenseEmbedding denseRange_pureCauchy
theorem
CauchyFilter.isDenseEmbedding_pureCauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "IsDenseEmbedding" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
nonempty_cauchyFilter_iff : Nonempty (CauchyFilter α) ↔ Nonempty α
by constructor <;> rintro ⟨c⟩ · have := eq_univ_iff_forall.1 isDenseEmbedding_pureCauchy.isDenseInducing.closure_range c obtain ⟨_, ⟨_, a, _⟩⟩ := mem_closure_iff.1 this _ isOpen_univ trivial exact ⟨a⟩ · exact ⟨pureCauchy c⟩
theorem
CauchyFilter.nonempty_cauchyFilter_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "isOpen_univ" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
extend (f : α → β) : CauchyFilter α → β
if UniformContinuous f then isDenseInducing_pureCauchy.extend f else fun x => f (nonempty_cauchyFilter_iff.1 ⟨x⟩).some
def
CauchyFilter.extend
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "UniformContinuous" ]
Extend a uniformly continuous function `α → β` to a function `CauchyFilter α → β`. Outputs junk when `f` is not uniformly continuous.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
extend_pureCauchy {f : α → β} (hf : UniformContinuous f) (a : α) : extend f (pureCauchy a) = f a
by rw [extend, if_pos hf] exact uniformly_extend_of_ind isUniformInducing_pureCauchy denseRange_pureCauchy hf _
theorem
CauchyFilter.extend_pureCauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "UniformContinuous", "uniformly_extend_of_ind" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_extend {f : α → β} : UniformContinuous (extend f)
by by_cases hf : UniformContinuous f · rw [extend, if_pos hf] exact uniformContinuous_uniformly_extend isUniformInducing_pureCauchy denseRange_pureCauchy hf · rw [extend, if_neg hf] exact uniformContinuous_of_const fun a _b => by congr
theorem
CauchyFilter.uniformContinuous_extend
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "UniformContinuous", "by_cases", "uniformContinuous_of_const", "uniformContinuous_uniformly_extend" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
inseparable_iff {f g : CauchyFilter α} : Inseparable f g ↔ f.1 ×ˢ g.1 ≤ 𝓤 α
(basis_uniformity (basis_sets _)).inseparable_iff_uniformity
theorem
CauchyFilter.inseparable_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "Inseparable" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
inseparable_iff_of_le_nhds {f g : CauchyFilter α} {a b : α} (ha : f.1 ≤ 𝓝 a) (hb : g.1 ≤ 𝓝 b) : Inseparable a b ↔ Inseparable f g
by rw [← tendsto_id'] at ha hb rw [inseparable_iff, (ha.comp tendsto_fst).inseparable_iff_uniformity (hb.comp tendsto_snd)] simp only [Function.comp_apply, id_eq, Prod.mk.eta, ← Function.id_def, tendsto_id']
theorem
CauchyFilter.inseparable_iff_of_le_nhds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Completion.lean
[]
[ "CauchyFilter", "Inseparable", "Prod.mk.eta" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319