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CauchySeq.tendsto_uniformity [Preorder β] {u : β → α} (h : CauchySeq u) : Tendsto (Prod.map u u) atTop (𝓤 α)
by simpa only [Tendsto, prod_map_map_eq', prod_atTop_atTop_eq] using h.right
theorem
CauchySeq.tendsto_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Preorder" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.nonempty [Preorder β] {u : β → α} (hu : CauchySeq u) : Nonempty β
@nonempty_of_neBot _ _ <| (map_neBot_iff _).1 hu.1
theorem
CauchySeq.nonempty
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Preorder" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.mem_entourage {β : Type*} [SemilatticeSup β] {u : β → α} (h : CauchySeq u) {V : SetRel α α} (hV : V ∈ 𝓤 α) : ∃ k₀, ∀ i j, k₀ ≤ i → k₀ ≤ j → (u i, u j) ∈ V
by haveI := h.nonempty have := h.tendsto_uniformity; rw [← prod_atTop_atTop_eq] at this simpa [MapsTo] using atTop_basis.prod_self.tendsto_left_iff.1 this V hV
theorem
CauchySeq.mem_entourage
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SemilatticeSup", "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.Tendsto.cauchySeq [SemilatticeSup β] [Nonempty β] {f : β → α} {x} (hx : Tendsto f atTop (𝓝 x)) : CauchySeq f
hx.cauchy_map
theorem
Filter.Tendsto.cauchySeq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SemilatticeSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_const [SemilatticeSup β] [Nonempty β] (x : α) : CauchySeq fun _ : β => x
tendsto_const_nhds.cauchySeq
theorem
cauchySeq_const
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SemilatticeSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_iff_tendsto [Nonempty β] [SemilatticeSup β] {u : β → α} : CauchySeq u ↔ Tendsto (Prod.map u u) atTop (𝓤 α)
cauchy_map_iff'.trans <| by simp only [prod_atTop_atTop_eq, Prod.map_def]
theorem
cauchySeq_iff_tendsto
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Prod.map_def", "SemilatticeSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.comp_tendsto {γ} [Preorder β] [SemilatticeSup γ] [Nonempty γ] {f : β → α} (hf : CauchySeq f) {g : γ → β} (hg : Tendsto g atTop atTop) : CauchySeq (f ∘ g)
⟨inferInstance, le_trans (prod_le_prod.mpr ⟨Tendsto.comp le_rfl hg, Tendsto.comp le_rfl hg⟩) hf.2⟩
theorem
CauchySeq.comp_tendsto
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Preorder", "SemilatticeSup", "le_rfl", "le_trans" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.comp_injective [SemilatticeSup β] [NoMaxOrder β] [Nonempty β] {u : ℕ → α} (hu : CauchySeq u) {f : β → ℕ} (hf : Injective f) : CauchySeq (u ∘ f)
hu.comp_tendsto <| Nat.cofinite_eq_atTop ▸ hf.tendsto_cofinite.mono_left atTop_le_cofinite
theorem
CauchySeq.comp_injective
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Nat.cofinite_eq_atTop", "NoMaxOrder", "SemilatticeSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Function.Bijective.cauchySeq_comp_iff {f : ℕ → ℕ} (hf : Bijective f) (u : ℕ → α) : CauchySeq (u ∘ f) ↔ CauchySeq u
by refine ⟨fun H => ?_, fun H => H.comp_injective hf.injective⟩ lift f to ℕ ≃ ℕ using hf simpa only [Function.comp_def, f.apply_symm_apply] using H.comp_injective f.symm.injective
theorem
Function.Bijective.cauchySeq_comp_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.subseq_subseq_mem {V : ℕ → SetRel α α} (hV : ∀ n, V n ∈ 𝓤 α) {u : ℕ → α} (hu : CauchySeq u) {f g : ℕ → ℕ} (hf : Tendsto f atTop atTop) (hg : Tendsto g atTop atTop) : ∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, ((u ∘ f ∘ φ) n, (u ∘ g ∘ φ) n) ∈ V n
by rw [cauchySeq_iff_tendsto] at hu exact ((hu.comp <| hf.prod_atTop hg).comp tendsto_atTop_diagonal).subseq_mem hV
theorem
CauchySeq.subseq_subseq_mem
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SetRel", "StrictMono", "cauchySeq_iff_tendsto" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_iff' {u : ℕ → α} : CauchySeq u ↔ ∀ V ∈ 𝓤 α, ∀ᶠ k in atTop, k ∈ Prod.map u u ⁻¹' V
cauchySeq_iff_tendsto
theorem
cauchySeq_iff'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "cauchySeq_iff_tendsto" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_iff {u : ℕ → α} : CauchySeq u ↔ ∀ V ∈ 𝓤 α, ∃ N, ∀ k ≥ N, ∀ l ≥ N, (u k, u l) ∈ V
by simp only [cauchySeq_iff', Filter.eventually_atTop_prod_self', mem_preimage, Prod.map_apply]
theorem
cauchySeq_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Filter.eventually_atTop_prod_self'", "cauchySeq_iff'" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.prodMap {γ δ} [UniformSpace β] [Preorder γ] [Preorder δ] {u : γ → α} {v : δ → β} (hu : CauchySeq u) (hv : CauchySeq v) : CauchySeq (Prod.map u v)
by simpa only [CauchySeq, prod_map_map_eq', prod_atTop_atTop_eq] using hu.prod hv
theorem
CauchySeq.prodMap
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Preorder", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.prodMk {γ} [UniformSpace β] [Preorder γ] {u : γ → α} {v : γ → β} (hu : CauchySeq u) (hv : CauchySeq v) : CauchySeq fun x => (u x, v x)
haveI := hu.1.of_map (Cauchy.prod hu hv).mono (tendsto_map.prodMk tendsto_map)
theorem
CauchySeq.prodMk
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy.prod", "CauchySeq", "Preorder", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.eventually_eventually [Preorder β] {u : β → α} (hu : CauchySeq u) {V : SetRel α α} (hV : V ∈ 𝓤 α) : ∀ᶠ k in atTop, ∀ᶠ l in atTop, (u k, u l) ∈ V
eventually_atTop_curry <| hu.tendsto_uniformity hV
theorem
CauchySeq.eventually_eventually
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Preorder", "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformContinuous.comp_cauchySeq {γ} [UniformSpace β] [Preorder γ] {f : α → β} (hf : UniformContinuous f) {u : γ → α} (hu : CauchySeq u) : CauchySeq (f ∘ u)
hu.map hf
theorem
UniformContinuous.comp_cauchySeq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Preorder", "UniformContinuous", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.subseq_mem {V : ℕ → SetRel α α} (hV : ∀ n, V n ∈ 𝓤 α) {u : ℕ → α} (hu : CauchySeq u) : ∃ φ : ℕ → ℕ, StrictMono φ ∧ ∀ n, (u <| φ (n + 1), u <| φ n) ∈ V n
by have : ∀ n, ∃ N, ∀ k ≥ N, ∀ l ≥ k, (u l, u k) ∈ V n := fun n => by rw [cauchySeq_iff] at hu rcases hu _ (hV n) with ⟨N, H⟩ exact ⟨N, fun k hk l hl => H _ (le_trans hk hl) _ hk⟩ obtain ⟨φ : ℕ → ℕ, φ_extr : StrictMono φ, hφ : ∀ n, ∀ l ≥ φ n, (u l, u <| φ n) ∈ V n⟩ := extraction_forall_of_eventually...
theorem
CauchySeq.subseq_mem
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SetRel", "StrictMono", "cauchySeq_iff", "le_trans" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.Tendsto.subseq_mem_entourage {V : ℕ → SetRel α α} (hV : ∀ n, V n ∈ 𝓤 α) {u : ℕ → α} {a : α} (hu : Tendsto u atTop (𝓝 a)) : ∃ φ : ℕ → ℕ, StrictMono φ ∧ (u (φ 0), a) ∈ V 0 ∧ ∀ n, (u <| φ (n + 1), u <| φ n) ∈ V (n + 1)
by rcases mem_atTop_sets.1 (hu (ball_mem_nhds a (symm_le_uniformity <| hV 0))) with ⟨n, hn⟩ rcases (hu.comp (tendsto_add_atTop_nat n)).cauchySeq.subseq_mem fun n => hV (n + 1) with ⟨φ, φ_mono, hφV⟩ exact ⟨fun k => φ k + n, φ_mono.add_const _, hn _ le_add_self, hφV⟩
theorem
Filter.Tendsto.subseq_mem_entourage
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "SetRel", "StrictMono", "symm_le_uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendsto_nhds_of_cauchySeq_of_subseq [Preorder β] {u : β → α} (hu : CauchySeq u) {ι : Type*} {f : ι → β} {p : Filter ι} [NeBot p] (hf : Tendsto f p atTop) {a : α} (ha : Tendsto (u ∘ f) p (𝓝 a)) : Tendsto u atTop (𝓝 a)
le_nhds_of_cauchy_adhp hu (ha.mapClusterPt.of_comp hf)
theorem
tendsto_nhds_of_cauchySeq_of_subseq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "Filter", "Preorder", "le_nhds_of_cauchy_adhp" ]
If a Cauchy sequence has a convergent subsequence, then it converges.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_shift {u : ℕ → α} (k : ℕ) : CauchySeq (fun n ↦ u (n + k)) ↔ CauchySeq u
by constructor <;> intro h · rw [cauchySeq_iff] at h ⊢ intro V mV obtain ⟨N, h⟩ := h V mV use N + k intro a ha b hb convert! h (a - k) (Nat.le_sub_of_add_le ha) (b - k) (Nat.le_sub_of_add_le hb) <;> lia · exact h.comp_tendsto (tendsto_add_atTop_nat k)
theorem
cauchySeq_shift
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "cauchySeq_iff" ]
Any shift of a Cauchy sequence is also a Cauchy sequence.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.cauchySeq_iff {γ} [Nonempty β] [SemilatticeSup β] {u : β → α} {p : γ → Prop} {s : γ → SetRel α α} (h : (𝓤 α).HasBasis p s) : CauchySeq u ↔ ∀ i, p i → ∃ N, ∀ m, N ≤ m → ∀ n, N ≤ n → (u m, u n) ∈ s i
by rw [cauchySeq_iff_tendsto, ← prod_atTop_atTop_eq] refine (atTop_basis.prod_self.tendsto_iff h).trans ?_ simp only [true_and, Prod.forall, mem_prod_eq, mem_Ici, and_imp, Prod.map, @forall_comm (_ ≤ _) β]
theorem
Filter.HasBasis.cauchySeq_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SemilatticeSup", "SetRel", "cauchySeq_iff_tendsto", "trans" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.cauchySeq_iff' {γ} [Nonempty β] [SemilatticeSup β] {u : β → α} {p : γ → Prop} {s : γ → SetRel α α} (H : (𝓤 α).HasBasis p s) : CauchySeq u ↔ ∀ i, p i → ∃ N, ∀ n ≥ N, (u n, u N) ∈ s i
by refine H.cauchySeq_iff.trans ⟨fun h i hi => ?_, fun h i hi => ?_⟩ · exact (h i hi).imp fun N hN n hn => hN n hn N le_rfl · rcases comp_symm_of_uniformity (H.mem_of_mem hi) with ⟨t, ht, ht', hts⟩ rcases H.mem_iff.1 ht with ⟨j, hj, hjt⟩ refine (h j hj).imp fun N hN m hm n hn => hts ⟨u N, hjt ?_, ht' <| h...
theorem
Filter.HasBasis.cauchySeq_iff'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SemilatticeSup", "SetRel", "comp_symm_of_uniformity", "le_rfl" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_of_controlled [SemilatticeSup β] [Nonempty β] (U : β → SetRel α α) (hU : ∀ s ∈ 𝓤 α, ∃ n, U n ⊆ s) {f : β → α} (hf : ∀ ⦃N m n : β⦄, N ≤ m → N ≤ n → (f m, f n) ∈ U N) : CauchySeq f
cauchySeq_iff_tendsto.2 (by intro s hs rw [mem_map, mem_atTop_sets] obtain ⟨N, hN⟩ := hU s hs refine ⟨(N, N), fun mn hmn => ?_⟩ obtain ⟨m, n⟩ := mn exact hN (hf hmn.1 hmn.2))
theorem
cauchySeq_of_controlled
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "SemilatticeSup", "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isComplete_iff_clusterPt {s : Set α} : IsComplete s ↔ ∀ l, Cauchy l → l ≤ 𝓟 s → ∃ x ∈ s, ClusterPt x l
forall₃_congr fun _ hl _ => exists_congr fun _ => and_congr_right fun _ => le_nhds_iff_adhp_of_cauchy hl
theorem
isComplete_iff_clusterPt
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "ClusterPt", "IsComplete", "Set", "le_nhds_iff_adhp_of_cauchy" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isComplete_iff_ultrafilter {s : Set α} : IsComplete s ↔ ∀ l : Ultrafilter α, Cauchy (l : Filter α) → ↑l ≤ 𝓟 s → ∃ x ∈ s, ↑l ≤ 𝓝 x
by refine ⟨fun h l => h l, fun H => isComplete_iff_clusterPt.2 fun l hl hls => ?_⟩ haveI := hl.1 rcases H (Ultrafilter.of l) hl.ultrafilter_of ((Ultrafilter.of_le l).trans hls) with ⟨x, hxs, hxl⟩ exact ⟨x, hxs, (ClusterPt.of_le_nhds hxl).mono (Ultrafilter.of_le l)⟩
theorem
isComplete_iff_ultrafilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "ClusterPt.of_le_nhds", "Filter", "IsComplete", "Set", "Ultrafilter", "Ultrafilter.of", "Ultrafilter.of_le", "trans" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isComplete_iff_ultrafilter' {s : Set α} : IsComplete s ↔ ∀ l : Ultrafilter α, Cauchy (l : Filter α) → s ∈ l → ∃ x ∈ s, ↑l ≤ 𝓝 x
isComplete_iff_ultrafilter.trans <| by simp only [le_principal_iff, Ultrafilter.mem_coe]
theorem
isComplete_iff_ultrafilter'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter", "IsComplete", "Set", "Ultrafilter", "Ultrafilter.mem_coe" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsComplete.union {s t : Set α} (hs : IsComplete s) (ht : IsComplete t) : IsComplete (s ∪ t)
by simp only [isComplete_iff_ultrafilter', Ultrafilter.union_mem_iff, or_imp] at * exact fun l hl => ⟨fun hsl => (hs l hl hsl).imp fun x hx => ⟨Or.inl hx.1, hx.2⟩, fun htl => (ht l hl htl).imp fun x hx => ⟨Or.inr hx.1, hx.2⟩⟩
theorem
IsComplete.union
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "IsComplete", "Set", "Ultrafilter.union_mem_iff", "isComplete_iff_ultrafilter'" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isComplete_iUnion_separated {ι : Sort*} {s : ι → Set α} (hs : ∀ i, IsComplete (s i)) {U : SetRel α α} (hU : U ∈ 𝓤 α) (hd : ∀ (i j : ι), ∀ x ∈ s i, ∀ y ∈ s j, (x, y) ∈ U → i = j) : IsComplete (⋃ i, s i)
by set S := ⋃ i, s i intro l hl hls rw [le_principal_iff] at hls obtain ⟨hl_ne, hl'⟩ := cauchy_iff.1 hl obtain ⟨t, htS, htl, htU⟩ : ∃ t, t ⊆ S ∧ t ∈ l ∧ t ×ˢ t ⊆ U := by rcases hl' U hU with ⟨t, htl, htU⟩ refine ⟨t ∩ S, inter_subset_right, inter_mem htl hls, Subset.trans ?_ htU⟩ gcongr <;> apply i...
theorem
isComplete_iUnion_separated
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter.nonempty_of_mem", "IsComplete", "Set", "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CompleteSpace (α : Type u) [UniformSpace α] : Prop where /-- In a complete uniform space, every Cauchy filter converges. -/ complete : ∀ {f : Filter α}, Cauchy f → ∃ x, f ≤ 𝓝 x
class
CompleteSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter", "UniformSpace" ]
A complete space is defined here using uniformities. A uniform space is complete if every Cauchy filter converges.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
complete_univ {α : Type u} [UniformSpace α] [CompleteSpace α] : IsComplete (univ : Set α)
fun f hf _ => by rcases CompleteSpace.complete hf with ⟨x, hx⟩ exact ⟨x, mem_univ x, hx⟩
theorem
complete_univ
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "IsComplete", "Set", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CompleteSpace.prod [UniformSpace β] [CompleteSpace α] [CompleteSpace β] : CompleteSpace (α × β)
where complete hf := let ⟨x1, hx1⟩ := CompleteSpace.complete <| hf.map uniformContinuous_fst let ⟨x2, hx2⟩ := CompleteSpace.complete <| hf.map uniformContinuous_snd ⟨(x1, x2), by rw [nhds_prod_eq, le_prod]; constructor <;> assumption⟩
instance
CompleteSpace.prod
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "UniformSpace", "nhds_prod_eq", "uniformContinuous_fst", "uniformContinuous_snd" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CompleteSpace.fst_of_prod [UniformSpace β] [CompleteSpace (α × β)] [h : Nonempty β] : CompleteSpace α
where complete hf := let ⟨y⟩ := h let ⟨(a, b), hab⟩ := CompleteSpace.complete <| hf.prod <| cauchy_pure (a := y) ⟨a, by simpa only [map_fst_prod, nhds_prod_eq] using map_mono (m := Prod.fst) hab⟩
lemma
CompleteSpace.fst_of_prod
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "UniformSpace", "cauchy_pure", "nhds_prod_eq" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CompleteSpace.snd_of_prod [UniformSpace β] [CompleteSpace (α × β)] [h : Nonempty α] : CompleteSpace β
where complete hf := let ⟨x⟩ := h let ⟨(a, b), hab⟩ := CompleteSpace.complete <| (cauchy_pure (a := x)).prod hf ⟨b, by simpa only [map_snd_prod, nhds_prod_eq] using map_mono (m := Prod.snd) hab⟩
lemma
CompleteSpace.snd_of_prod
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "UniformSpace", "cauchy_pure", "nhds_prod_eq" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
completeSpace_prod_of_nonempty [UniformSpace β] [Nonempty α] [Nonempty β] : CompleteSpace (α × β) ↔ CompleteSpace α ∧ CompleteSpace β
⟨fun _ ↦ ⟨.fst_of_prod (β := β), .snd_of_prod (α := α)⟩, fun ⟨_, _⟩ ↦ .prod⟩
lemma
completeSpace_prod_of_nonempty
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CompleteSpace.mulOpposite [CompleteSpace α] : CompleteSpace αᵐᵒᵖ
where complete hf := MulOpposite.op_surjective.exists.mpr <| let ⟨x, hx⟩ := CompleteSpace.complete (hf.map MulOpposite.uniformContinuous_unop) ⟨x, (map_le_iff_le_comap.mp hx).trans_eq <| MulOpposite.comap_unop_nhds _⟩
instance
CompleteSpace.mulOpposite
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "MulOpposite.comap_unop_nhds", "MulOpposite.uniformContinuous_unop" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
completeSpace_of_isComplete_univ (h : IsComplete (univ : Set α)) : CompleteSpace α
⟨fun hf => let ⟨x, _, hx⟩ := h _ hf ((@principal_univ α).symm ▸ le_top); ⟨x, hx⟩⟩
theorem
completeSpace_of_isComplete_univ
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "IsComplete", "Set", "le_top", "symm" ]
If `univ` is complete, the space is a complete space
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
completeSpace_iff_isComplete_univ : CompleteSpace α ↔ IsComplete (univ : Set α)
⟨@complete_univ α _, completeSpace_of_isComplete_univ⟩
theorem
completeSpace_iff_isComplete_univ
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "IsComplete", "Set", "complete_univ" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
completeSpace_iff_ultrafilter : CompleteSpace α ↔ ∀ l : Ultrafilter α, Cauchy (l : Filter α) → ∃ x : α, ↑l ≤ 𝓝 x
by simp [completeSpace_iff_isComplete_univ, isComplete_iff_ultrafilter]
theorem
completeSpace_iff_ultrafilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "CompleteSpace", "Filter", "Ultrafilter", "completeSpace_iff_isComplete_univ", "isComplete_iff_ultrafilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchy_iff_exists_le_nhds [CompleteSpace α] {l : Filter α} [NeBot l] : Cauchy l ↔ ∃ x, l ≤ 𝓝 x
⟨CompleteSpace.complete, fun ⟨_, hx⟩ => cauchy_nhds.mono hx⟩
theorem
cauchy_iff_exists_le_nhds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "CompleteSpace", "Filter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchy_map_iff_exists_tendsto [CompleteSpace α] {l : Filter β} {f : β → α} [NeBot l] : Cauchy (l.map f) ↔ ∃ x, Tendsto f l (𝓝 x)
cauchy_iff_exists_le_nhds
theorem
cauchy_map_iff_exists_tendsto
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "CompleteSpace", "Filter", "cauchy_iff_exists_le_nhds" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_tendsto_of_complete [Preorder β] [CompleteSpace α] {u : β → α} (H : CauchySeq u) : ∃ x, Tendsto u atTop (𝓝 x)
CompleteSpace.complete H
theorem
cauchySeq_tendsto_of_complete
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "CompleteSpace", "Preorder" ]
A Cauchy sequence in a complete space converges
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchySeq_tendsto_of_isComplete [Preorder β] {K : Set α} (h₁ : IsComplete K) {u : β → α} (h₂ : ∀ n, u n ∈ K) (h₃ : CauchySeq u) : ∃ v ∈ K, Tendsto u atTop (𝓝 v)
h₁ _ h₃ <| le_principal_iff.2 <| mem_map_iff_exists_image.2 ⟨univ, univ_mem, by rwa [image_univ, range_subset_iff]⟩
theorem
cauchySeq_tendsto_of_isComplete
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "IsComplete", "Preorder", "Set" ]
If `K` is a complete subset, then any Cauchy sequence in `K` converges to a point in `K`
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Cauchy.le_nhds_lim [CompleteSpace α] {f : Filter α} (hf : Cauchy f) : haveI
hf.1.nonempty; f ≤ 𝓝 (lim f) := _root_.le_nhds_lim (CompleteSpace.complete hf)
theorem
Cauchy.le_nhds_lim
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "CompleteSpace", "Filter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.tendsto_limUnder [Preorder β] [CompleteSpace α] {u : β → α} (h : CauchySeq u) : haveI
h.1.nonempty; Tendsto u atTop (𝓝 <| limUnder atTop u) := h.le_nhds_lim
theorem
CauchySeq.tendsto_limUnder
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "CompleteSpace", "Preorder" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.isComplete [CompleteSpace α] {s : Set α} (h : IsClosed s) : IsComplete s
fun _ cf fs => let ⟨x, hx⟩ := CompleteSpace.complete cf ⟨x, isClosed_iff_clusterPt.mp h x (cf.left.mono (le_inf hx fs)), hx⟩
theorem
IsClosed.isComplete
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "IsClosed", "IsComplete", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
eq_pure_of_cauchy {f : Filter α} (hf : Cauchy f) : ∃ x : α, f = pure x
by rcases hf with ⟨f_ne_bot, f_le⟩ simp only [DiscreteUniformity.eq_principal_setRelId, le_principal_iff, mem_prod_iff] at f_le obtain ⟨S, hS, T, hT, H⟩ := f_le obtain ⟨x, rfl, _, _, _⟩ := SetRel.exists_eq_singleton_of_prod_subset_id (f_ne_bot.nonempty_of_mem hS) (f_ne_bot.nonempty_of_mem hT) H exact ⟨x, ...
theorem
DiscreteUniformity.eq_pure_of_cauchy
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "DiscreteUniformity.eq_principal_setRelId", "Filter", "SetRel.exists_eq_singleton_of_prod_subset_id" ]
A Cauchy filter in a discrete uniform space is contained in the principal filter of a point.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
cauchyConst {f : Filter α} (hf : Cauchy f) : α
(eq_pure_of_cauchy hf).choose
def
DiscreteUniformity.cauchyConst
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter" ]
A constant to which a Cauchy filter in a discrete uniform space converges.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
eq_pure_cauchyConst {f : Filter α} (hf : Cauchy f) : f = pure (cauchyConst hf)
(eq_pure_of_cauchy hf).choose_spec
theorem
DiscreteUniformity.eq_pure_cauchyConst
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded (s : Set α) : Prop
∀ d ∈ 𝓤 α, ∃ t : Set α, t.Finite ∧ s ⊆ ⋃ y ∈ t, { x | (x, y) ∈ d }
def
TotallyBounded
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set" ]
A set `s` is totally bounded if for every entourage `d` there is a finite set of points `t` such that every element of `s` is `d`-near to some element of `t`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded (f : Filter α)
∀ d : SetRel α α, d ∈ 𝓤 α → ∃ t : Set α, t.Finite ∧ d.preimage t ∈ f
def
Filter.TotallyBounded
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "Set", "SetRel" ]
A filter `f` is totally bounded if for every entourage `d`, the `d`-neighborhood of some finite set is in `f`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.totallyBounded_principal_iff {s : Set α} : (𝓟 s).TotallyBounded ↔ TotallyBounded s
by simp only [Filter.TotallyBounded, mem_principal, SetRel.preimage_eq_biUnion, TotallyBounded]
theorem
Filter.totallyBounded_principal_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter.TotallyBounded", "Set", "SetRel.preimage_eq_biUnion", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded.exists_subset_of_mem {f : Filter α} (hf : f.TotallyBounded) {s : Set α} (hs : s ∈ f) {U : SetRel α α} (hU : U ∈ 𝓤 α) : ∃ t ⊆ s, Set.Finite t ∧ U.preimage t ∈ f
by rcases comp_symm_of_uniformity hU with ⟨r, hr, rs, rU⟩ rcases hf r hr with ⟨k, fk, ks⟩ let u := k ∩ { y | ∃ x ∈ s, (x, y) ∈ r } choose g hgs hgr using fun x : u => x.coe_prop.2 refine ⟨range g, ?_, ?_, ?_⟩ · exact range_subset_iff.2 hgs · haveI : Fintype u := (fk.inter_of_left _).fintype exact fini...
theorem
Filter.TotallyBounded.exists_subset_of_mem
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "Fintype", "Set", "Set.Finite", "SetRel", "SetRel.preimage", "comp_symm_of_uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded.exists_subset {s : Set α} (hs : TotallyBounded s) {U : SetRel α α} (hU : U ∈ 𝓤 α) : ∃ t, t ⊆ s ∧ Set.Finite t ∧ s ⊆ ⋃ y ∈ t, { x | (x, y) ∈ U }
by rw [← Filter.totallyBounded_principal_iff] at hs simp_rw [← SetRel.preimage_eq_biUnion] exact hs.exists_subset_of_mem (Filter.mem_principal_self s) hU
theorem
TotallyBounded.exists_subset
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter.mem_principal_self", "Filter.totallyBounded_principal_iff", "Set", "Set.Finite", "SetRel", "SetRel.preimage_eq_biUnion", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_iff_subset {s : Set α} : TotallyBounded s ↔ ∀ d ∈ 𝓤 α, ∃ t, t ⊆ s ∧ Set.Finite t ∧ s ⊆ ⋃ y ∈ t, { x | (x, y) ∈ d }
⟨fun H _ hd ↦ H.exists_subset hd, fun H d hd ↦ let ⟨t, _, ht⟩ := H d hd; ⟨t, ht⟩⟩
theorem
totallyBounded_iff_subset
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "Set.Finite", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.totallyBounded_iff {ι} {p : ι → Prop} {U : ι → SetRel α α} (H : (𝓤 α).HasBasis p U) {s : Set α} : TotallyBounded s ↔ ∀ i, p i → ∃ t : Set α, Set.Finite t ∧ s ⊆ ⋃ y ∈ t, { x | (x, y) ∈ U i }
H.forall_iff fun _ _ hUV h => h.imp fun _ ht => ⟨ht.1, ht.2.trans <| iUnion₂_mono fun _ _ _ hy => hUV hy⟩
theorem
Filter.HasBasis.totallyBounded_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "Set.Finite", "SetRel", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.HasBasis.filter_totallyBounded_iff {ι} {p : ι → Prop} {U : ι → SetRel α α} (H : (𝓤 α).HasBasis p U) {f : Filter α} : f.TotallyBounded ↔ ∀ i, p i → ∃ t : Set α, Set.Finite t ∧ (U i).preimage t ∈ f
H.forall_iff fun _ _ _ h => h.imp fun _ ht => ⟨ht.1, f.mem_of_superset ht.2 <| by gcongr⟩
theorem
Filter.HasBasis.filter_totallyBounded_iff
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "Set", "Set.Finite", "SetRel" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_of_forall_isSymm {s : Set α} (h : ∀ V ∈ 𝓤 α, SetRel.IsSymm V → ∃ t : Set α, Set.Finite t ∧ s ⊆ ⋃ y ∈ t, ball y V) : TotallyBounded s
UniformSpace.hasBasis_symmetric.totallyBounded_iff.2 fun V ⟨_, _⟩ => by simpa only [ball_eq_of_symmetry] using! h V ‹_› ‹_›
theorem
totallyBounded_of_forall_isSymm
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "Set.Finite", "SetRel.IsSymm", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded.subset {s₁ s₂ : Set α} (hs : s₁ ⊆ s₂) (h : TotallyBounded s₂) : TotallyBounded s₁
fun d hd => let ⟨t, ht₁, ht₂⟩ := h d hd ⟨t, ht₁, Subset.trans hs ht₂⟩
theorem
TotallyBounded.subset
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded.mono {f g : Filter α} (h : f ≤ g) (hg : g.TotallyBounded) : f.TotallyBounded
fun U hU => (hg U hU).imp fun _ => And.imp_right (@h _)
theorem
Filter.TotallyBounded.mono
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded.totallyBounded_setOf_clusterPt {f : Filter α} (h : f.TotallyBounded) : TotallyBounded {x | ClusterPt x f}
by refine uniformity_hasBasis_closed.totallyBounded_iff.2 fun V hV => ?_ obtain ⟨t, htf, hst⟩ := h V hV.1 refine ⟨t, htf, fun x hx => ?_⟩ rw [← SetRel.preimage_eq_biUnion, id, ← (hV.2.relPreimage_of_finite htf).closure_eq] exact hx.mem_closure_of_mem _ hst
theorem
Filter.TotallyBounded.totallyBounded_setOf_clusterPt
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "ClusterPt", "Filter", "SetRel.preimage_eq_biUnion", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded.closure {s : Set α} (h : TotallyBounded s) : TotallyBounded (closure s)
by rw [closure_eq_cluster_pts] exact (Filter.totallyBounded_principal_iff.mpr h).totallyBounded_setOf_clusterPt
theorem
TotallyBounded.closure
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded", "closure", "closure_eq_cluster_pts" ]
The closure of a totally bounded set is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_closure {s : Set α} : TotallyBounded (closure s) ↔ TotallyBounded s
⟨fun h ↦ h.subset subset_closure, TotallyBounded.closure⟩
lemma
totallyBounded_closure
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded", "closure", "subset_closure" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.totallyBounded_iSup {ι : Sort*} [Finite ι] {f : ι → Filter α} : (⨆ i, f i).TotallyBounded ↔ ∀ i, (f i).TotallyBounded
by refine ⟨fun h i ↦ h.mono (le_iSup _ _), fun h U hU ↦ ?_⟩ choose t htf ht using (h · U hU) refine ⟨⋃ i, t i, finite_iUnion htf, ?_⟩ simp_rw [U.preimage_iUnion, ← le_principal_iff, ← iSup_principal] at ht ⊢ gcongr; apply ht
lemma
Filter.totallyBounded_iSup
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "Finite", "TotallyBounded", "le_iSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.totallyBounded_biSup {ι : Type*} {I : Set ι} (hI : I.Finite) {f : ι → Filter α} : (⨆ i ∈ I, f i).TotallyBounded ↔ ∀ i ∈ I, (f i).TotallyBounded
by have := hI.to_subtype rw [iSup_subtype', totallyBounded_iSup, Subtype.forall]
lemma
Filter.totallyBounded_biSup
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "Set", "TotallyBounded", "iSup_subtype'" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_sSup {S : Set (Filter α)} (hS : S.Finite) : (sSup S).TotallyBounded ↔ ∀ f ∈ S, f.TotallyBounded
by rw [sSup_eq_iSup, totallyBounded_biSup hS]
lemma
totallyBounded_sSup
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "Set", "TotallyBounded", "sSup_eq_iSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_iUnion {ι : Sort*} [Finite ι] {s : ι → Set α} : TotallyBounded (⋃ i, s i) ↔ ∀ i, TotallyBounded (s i)
by simp_rw [← Filter.totallyBounded_principal_iff, ← Filter.iSup_principal, Filter.totallyBounded_iSup]
lemma
totallyBounded_iUnion
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter.iSup_principal", "Filter.totallyBounded_iSup", "Filter.totallyBounded_principal_iff", "Finite", "Set", "TotallyBounded" ]
A finite indexed union is totally bounded if and only if each set of the family is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_biUnion {ι : Type*} {I : Set ι} (hI : I.Finite) {s : ι → Set α} : TotallyBounded (⋃ i ∈ I, s i) ↔ ∀ i ∈ I, TotallyBounded (s i)
by have := hI.to_subtype rw [biUnion_eq_iUnion, totallyBounded_iUnion, Subtype.forall]
lemma
totallyBounded_biUnion
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded", "totallyBounded_iUnion" ]
A union indexed by a finite set is totally bounded if and only if each set of the family is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_sUnion {S : Set (Set α)} (hS : S.Finite) : TotallyBounded (⋃₀ S) ↔ ∀ s ∈ S, TotallyBounded s
by rw [sUnion_eq_biUnion, totallyBounded_biUnion hS]
lemma
totallyBounded_sUnion
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded", "totallyBounded_biUnion" ]
A union of a finite family of sets is totally bounded if and only if each set of the family is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Set.Finite.totallyBounded {s : Set α} (hs : s.Finite) : TotallyBounded s
fun _U hU ↦ ⟨s, hs, fun _x hx ↦ mem_biUnion hx <| refl_mem_uniformity hU⟩
lemma
Set.Finite.totallyBounded
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded", "refl_mem_uniformity" ]
A finite set is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Set.Subsingleton.totallyBounded {s : Set α} (hs : s.Subsingleton) : TotallyBounded s
hs.finite.totallyBounded
lemma
Set.Subsingleton.totallyBounded
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded" ]
A subsingleton is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_singleton (a : α) : TotallyBounded {a}
(finite_singleton a).totallyBounded
lemma
totallyBounded_singleton
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_empty : TotallyBounded (∅ : Set α)
finite_empty.totallyBounded
theorem
totallyBounded_empty
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.totallyBounded_bot : (⊥ : Filter α).TotallyBounded
by rw [← principal_empty, totallyBounded_principal_iff] exact totallyBounded_empty
theorem
Filter.totallyBounded_bot
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "TotallyBounded", "totallyBounded_empty" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_union {s t : Set α} : TotallyBounded (s ∪ t) ↔ TotallyBounded s ∧ TotallyBounded t
by rw [union_eq_iUnion, totallyBounded_iUnion] simp [and_comm]
lemma
totallyBounded_union
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded", "totallyBounded_iUnion" ]
The union of two sets is totally bounded if and only if each of the two sets is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded.union {s t : Set α} (hs : TotallyBounded s) (ht : TotallyBounded t) : TotallyBounded (s ∪ t)
totallyBounded_union.2 ⟨hs, ht⟩
lemma
TotallyBounded.union
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded" ]
The union of two totally bounded sets is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_insert (a : α) {s : Set α} : TotallyBounded (insert a s) ↔ TotallyBounded s
by simp_rw [← singleton_union, totallyBounded_union, totallyBounded_singleton, true_and] protected alias ⟨_, TotallyBounded.insert⟩ := totallyBounded_insert
lemma
totallyBounded_insert
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "TotallyBounded", "totallyBounded_singleton", "totallyBounded_union" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.totallyBounded_sup {f g : Filter α} : (f ⊔ g).TotallyBounded ↔ f.TotallyBounded ∧ g.TotallyBounded
by rw [sup_eq_iSup, totallyBounded_iSup] simp [and_comm]
lemma
Filter.totallyBounded_sup
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "TotallyBounded", "sup_eq_iSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded.sup {f g : Filter α} (hf : f.TotallyBounded) (hg : g.TotallyBounded) : (f ⊔ g).TotallyBounded
totallyBounded_sup.2 ⟨hf, hg⟩
lemma
Filter.TotallyBounded.sup
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded.map [UniformSpace β] {f : α → β} {g : Filter α} (hg : g.TotallyBounded) (hf : UniformContinuous f) : (g.map f).TotallyBounded
fun t ht => let ⟨c, hfc, hct⟩ := hg _ (hf ht) ⟨f '' c, hfc.image f, by simpa [SetRel.preimage]⟩
theorem
Filter.TotallyBounded.map
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter", "SetRel.preimage", "TotallyBounded", "UniformContinuous", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded.image [UniformSpace β] {f : α → β} {s : Set α} (hs : TotallyBounded s) (hf : UniformContinuous f) : TotallyBounded (f '' s)
by simp only [← Filter.totallyBounded_principal_iff, ← Filter.map_principal] at hs ⊢ exact hs.map hf
theorem
TotallyBounded.image
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter.map_principal", "Filter.totallyBounded_principal_iff", "Set", "TotallyBounded", "UniformContinuous", "UniformSpace" ]
The image of a totally bounded set under a uniformly continuous map is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Ultrafilter.cauchy_of_totallyBounded' (f : Ultrafilter α) (hf : f.TotallyBounded) : Cauchy (f : Filter α)
⟨f.neBot', fun _ ht => let ⟨t', ht'₁, ht'_symm, ht'_t⟩ := comp_symm_of_uniformity ht let ⟨i, hi, ht'_f⟩ := hf t' ht'₁ have : ∃ y ∈ i, { x | (x, y) ∈ t' } ∈ f := (Ultrafilter.eventually_exists_mem_iff hi).1 ht'_f let ⟨y, _, hif⟩ := this have : {x | (x, y) ∈ t'} ×ˢ {x | (x, y) ∈ t'} ⊆ t' ○ t' := ...
theorem
Ultrafilter.cauchy_of_totallyBounded'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter", "Ultrafilter", "Ultrafilter.eventually_exists_mem_iff", "comp_symm_of_uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Ultrafilter.cauchy_of_totallyBounded {s : Set α} (f : Ultrafilter α) (hs : TotallyBounded s) (h : ↑f ≤ 𝓟 s) : Cauchy (f : Filter α)
f.cauchy_of_totallyBounded' <| (Filter.totallyBounded_principal_iff.mpr hs).mono h
theorem
Ultrafilter.cauchy_of_totallyBounded
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter", "Set", "TotallyBounded", "Ultrafilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.totallyBounded_iff_filter {g : Filter α} : g.TotallyBounded ↔ ∀ f, NeBot f → f ≤ g → ∃ c ≤ f, Cauchy c
by constructor · exact fun H f hf hfs => ⟨Ultrafilter.of f, Ultrafilter.of_le f, (Ultrafilter.of f).cauchy_of_totallyBounded' (H.mono ((Ultrafilter.of_le f).trans hfs))⟩ · intro H d hd contrapose! H with hd_cover set f := ⨅ t : Finset α, g ⊓ 𝓟 (d.preimage t)ᶜ have hb : Antitone fun t : Finset α...
theorem
Filter.totallyBounded_iff_filter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Antitone", "Cauchy", "Filter", "Filter.NeBot", "Filter.iInf_neBot_iff_of_directed'", "Finset", "SetRel.preimage", "Ultrafilter.of", "Ultrafilter.of_le", "trans" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.totallyBounded_iff_ultrafilter {g : Filter α} : g.TotallyBounded ↔ ∀ f : Ultrafilter α, ↑f ≤ g → Cauchy (f : Filter α)
by refine ⟨fun hg f hf => f.cauchy_of_totallyBounded' <| hg.mono hf, fun H => g.totallyBounded_iff_filter.2 ?_⟩ intro f hf hfs exact ⟨Ultrafilter.of f, Ultrafilter.of_le f, H _ ((Ultrafilter.of_le f).trans hfs)⟩
theorem
Filter.totallyBounded_iff_ultrafilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter", "Ultrafilter", "Ultrafilter.of_le", "trans" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_iff_filter {s : Set α} : TotallyBounded s ↔ ∀ f, NeBot f → f ≤ 𝓟 s → ∃ c ≤ f, Cauchy c
by rw [← Filter.totallyBounded_principal_iff, Filter.totallyBounded_iff_filter]
theorem
totallyBounded_iff_filter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter.totallyBounded_iff_filter", "Filter.totallyBounded_principal_iff", "Set", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_iff_ultrafilter {s : Set α} : TotallyBounded s ↔ ∀ f : Ultrafilter α, ↑f ≤ 𝓟 s → Cauchy (f : Filter α)
by rw [← Filter.totallyBounded_principal_iff, Filter.totallyBounded_iff_ultrafilter]
theorem
totallyBounded_iff_ultrafilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Cauchy", "Filter", "Filter.totallyBounded_iff_ultrafilter", "Filter.totallyBounded_principal_iff", "Set", "TotallyBounded", "Ultrafilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isCompact_iff_totallyBounded_isComplete {s : Set α} : IsCompact s ↔ TotallyBounded s ∧ IsComplete s
⟨fun hs => ⟨totallyBounded_iff_ultrafilter.2 fun f hf => let ⟨_, _, fx⟩ := isCompact_iff_ultrafilter_le_nhds.1 hs f hf cauchy_nhds.mono fx, fun f fc fs => let ⟨a, as, fa⟩ := @hs f fc.1 fs ⟨a, as, le_nhds_of_cauchy_adhp fc fa⟩⟩, fun ⟨ht, hc⟩ => isCompact_iff_ultrafilter_le_n...
theorem
isCompact_iff_totallyBounded_isComplete
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "IsCompact", "IsComplete", "Set", "TotallyBounded", "le_nhds_of_cauchy_adhp" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsCompact.totallyBounded {s : Set α} (h : IsCompact s) : TotallyBounded s
(isCompact_iff_totallyBounded_isComplete.1 h).1
theorem
IsCompact.totallyBounded
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "IsCompact", "Set", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsCompact.isComplete {s : Set α} (h : IsCompact s) : IsComplete s
(isCompact_iff_totallyBounded_isComplete.1 h).2
theorem
IsCompact.isComplete
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "IsCompact", "IsComplete", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded.isCompact_of_isComplete {s : Set α} (ht : TotallyBounded s) (hc : IsComplete s) : IsCompact s
isCompact_iff_totallyBounded_isComplete.mpr ⟨ht, hc⟩
theorem
TotallyBounded.isCompact_of_isComplete
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "IsCompact", "IsComplete", "Set", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TotallyBounded.isCompact_of_isClosed [CompleteSpace α] {s : Set α} (ht : TotallyBounded s) (hc : IsClosed s) : IsCompact s
ht.isCompact_of_isComplete hc.isComplete
theorem
TotallyBounded.isCompact_of_isClosed
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "IsClosed", "IsCompact", "Set", "TotallyBounded" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded.isCompact_setOf_clusterPt [CompleteSpace α] {f : Filter α} (hf : f.TotallyBounded) : IsCompact {x | ClusterPt x f}
hf.totallyBounded_setOf_clusterPt.isCompact_of_isClosed isClosed_setOf_clusterPt
theorem
Filter.TotallyBounded.isCompact_setOf_clusterPt
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "ClusterPt", "CompleteSpace", "Filter", "IsCompact", "isClosed_setOf_clusterPt" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Filter.TotallyBounded.exists_clusterPt [CompleteSpace α] {f : Filter α} [f.NeBot] (hf : f.TotallyBounded) : ∃ x, ClusterPt x f
by let m := Ultrafilter.of f have hmf : m ≤ f := Ultrafilter.of_le f have hm := m.cauchy_of_totallyBounded' (hf.mono hmf) obtain ⟨x, hx⟩ := CompleteSpace.complete hm rw [le_nhds_iff_adhp_of_cauchy hm] at hx exact ⟨x, hx.mono hmf⟩
theorem
Filter.TotallyBounded.exists_clusterPt
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "ClusterPt", "CompleteSpace", "Filter", "Ultrafilter.of", "Ultrafilter.of_le", "le_nhds_iff_adhp_of_cauchy" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
CauchySeq.totallyBounded_range {s : ℕ → α} (hs : CauchySeq s) : TotallyBounded (range s)
by intro a ha obtain ⟨n, hn⟩ := cauchySeq_iff.1 hs a ha refine ⟨s '' { k | k ≤ n }, (finite_le_nat _).image _, ?_⟩ rw [range_subset_iff, biUnion_image] intro m rw [mem_iUnion₂] rcases le_total m n with hm | hm exacts [⟨m, hm, refl_mem_uniformity ha⟩, ⟨n, le_refl n, hn m hm n le_rfl⟩]
theorem
CauchySeq.totallyBounded_range
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CauchySeq", "TotallyBounded", "le_refl", "le_total", "refl_mem_uniformity" ]
Every Cauchy sequence over `ℕ` is totally bounded.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
interUnionBalls (xs : ℕ → α) (u : ℕ → ℕ) (V : ℕ → SetRel α α) : Set α
⋂ n, ⋃ m ≤ u n, UniformSpace.ball (xs m) (Prod.swap ⁻¹' V n)
def
interUnionBalls
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "SetRel", "UniformSpace.ball" ]
Given a family of points `xs n`, a family of entourages `V n` of the diagonal and a family of natural numbers `u n`, the intersection over `n` of the `V n`-neighborhood of `xs 1, ..., xs (u n)`. Designed to be relatively compact when `V n` tends to the diagonal.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
totallyBounded_interUnionBalls {p : ℕ → Prop} {U : ℕ → SetRel α α} (H : (uniformity α).HasBasis p U) (xs : ℕ → α) (u : ℕ → ℕ) : TotallyBounded (interUnionBalls xs u U)
by rw [Filter.HasBasis.totallyBounded_iff H] intro i _ have h_subset : interUnionBalls xs u U ⊆ ⋃ m ≤ u i, UniformSpace.ball (xs m) (Prod.swap ⁻¹' U i) := fun x hx ↦ Set.mem_iInter.1 hx i classical refine ⟨Finset.image xs (Finset.range (u i + 1)), Finset.finite_toSet _, fun x hx ↦ ?_⟩ simp only [F...
lemma
totallyBounded_interUnionBalls
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Filter.HasBasis.totallyBounded_iff", "Finset.coe_image", "Finset.coe_range", "Finset.finite_toSet", "Finset.range", "SetRel", "TotallyBounded", "UniformSpace.ball", "interUnionBalls", "uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isCompact_closure_interUnionBalls {p : ℕ → Prop} {U : ℕ → SetRel α α} (H : (uniformity α).HasBasis p U) [CompleteSpace α] (xs : ℕ → α) (u : ℕ → ℕ) : IsCompact (closure (interUnionBalls xs u U))
by rw [isCompact_iff_totallyBounded_isComplete] refine ⟨TotallyBounded.closure ?_, isClosed_closure.isComplete⟩ exact totallyBounded_interUnionBalls H xs u
theorem
isCompact_closure_interUnionBalls
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "CompleteSpace", "IsCompact", "SetRel", "closure", "interUnionBalls", "isCompact_iff_totallyBounded_isComplete", "totallyBounded_interUnionBalls", "uniformity" ]
The construction `interUnionBalls` is used to have a relatively compact set.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
setSeqAux (n : ℕ) : { s : Set α // s ∈ f ∧ s ×ˢ s ⊆ U n }
Classical.indefiniteDescription _ <| (cauchy_iff.1 hf).2 (U n) (U_mem n)
def
SequentiallyComplete.setSeqAux
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set" ]
An auxiliary sequence of sets approximating a Cauchy filter.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
setSeq (n : ℕ) : Set α
⋂ m ∈ Set.Iic n, (setSeqAux hf U_mem m).val
def
SequentiallyComplete.setSeq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[ "Set", "Set.Iic" ]
Given a Cauchy filter `f` and a sequence `U` of entourages, `set_seq` provides an antitone sequence of sets `s n ∈ f` such that `s n ×ˢ s n ⊆ U`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
setSeq_mem (n : ℕ) : setSeq hf U_mem n ∈ f
(biInter_mem (finite_le_nat n)).2 fun m _ => (setSeqAux hf U_mem m).2.1
theorem
SequentiallyComplete.setSeq_mem
Topology.UniformSpace
Mathlib/Topology/UniformSpace/Cauchy.lean
[]
[]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319