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uniformCauchySeqOn_iff_uniformCauchySeqOnFilter : UniformCauchySeqOn F p s ↔ UniformCauchySeqOnFilter F p (𝓟 s)
by simp only [UniformCauchySeqOn, UniformCauchySeqOnFilter] refine forall₂_congr fun u hu => ?_ rw [eventually_prod_principal_iff]
theorem
uniformCauchySeqOn_iff_uniformCauchySeqOnFilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "UniformCauchySeqOn", "UniformCauchySeqOnFilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.uniformCauchySeqOnFilter (hF : UniformCauchySeqOn F p s) : UniformCauchySeqOnFilter F p (𝓟 s)
by rwa [← uniformCauchySeqOn_iff_uniformCauchySeqOnFilter]
theorem
UniformCauchySeqOn.uniformCauchySeqOnFilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "UniformCauchySeqOn", "UniformCauchySeqOnFilter", "uniformCauchySeqOn_iff_uniformCauchySeqOnFilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TendstoUniformlyOnFilter.uniformCauchySeqOnFilter (hF : TendstoUniformlyOnFilter F f p p') : UniformCauchySeqOnFilter F p p'
by intro u hu rcases comp_symm_of_uniformity hu with ⟨t, ht, htsymm, htmem⟩ have := tendsto_swap4_prod.eventually ((hF t ht).prod_mk (hF t ht)) apply this.diag_of_prod_right.mono simp only [and_imp, Prod.forall] intro n1 n2 x hl hr exact htmem <| SetRel.prodMk_mem_comp (htsymm hl) hr
theorem
TendstoUniformlyOnFilter.uniformCauchySeqOnFilter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "SetRel.prodMk_mem_comp", "TendstoUniformlyOnFilter", "UniformCauchySeqOnFilter", "comp_symm_of_uniformity" ]
A sequence that converges uniformly is also uniformly Cauchy
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TendstoUniformlyOn.uniformCauchySeqOn (hF : TendstoUniformlyOn F f p s) : UniformCauchySeqOn F p s
uniformCauchySeqOn_iff_uniformCauchySeqOnFilter.mpr hF.tendstoUniformlyOnFilter.uniformCauchySeqOnFilter
theorem
TendstoUniformlyOn.uniformCauchySeqOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "TendstoUniformlyOn", "UniformCauchySeqOn" ]
A sequence that converges uniformly is also uniformly Cauchy
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOnFilter.tendstoUniformlyOnFilter_of_tendsto (hF : UniformCauchySeqOnFilter F p p') (hF' : ∀ᶠ x : α in p', Tendsto (fun n => F n x) p (𝓝 (f x))) : TendstoUniformlyOnFilter F f p p'
by rcases p.eq_or_neBot with rfl | _ · simp only [TendstoUniformlyOnFilter, bot_prod, eventually_bot, implies_true] -- Proof idea: |f_n(x) - f(x)| ≤ |f_n(x) - f_m(x)| + |f_m(x) - f(x)|. We choose `n` -- so that |f_n(x) - f_m(x)| is uniformly small across `s` whenever `m ≥ n`. Then for -- a fixed `x`, we choos...
theorem
UniformCauchySeqOnFilter.tendstoUniformlyOnFilter_of_tendsto
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter.eventually_swap_iff", "Set.mem_of_mem_of_subset", "TendstoUniformlyOnFilter", "Uniform.tendsto_nhds_right", "UniformCauchySeqOnFilter", "comp_symm_of_uniformity" ]
A uniformly Cauchy sequence converges uniformly to its limit
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.tendstoUniformlyOn_of_tendsto (hF : UniformCauchySeqOn F p s) (hF' : ∀ x : α, x ∈ s → Tendsto (fun n => F n x) p (𝓝 (f x))) : TendstoUniformlyOn F f p s
tendstoUniformlyOn_iff_tendstoUniformlyOnFilter.mpr (hF.uniformCauchySeqOnFilter.tendstoUniformlyOnFilter_of_tendsto hF')
theorem
UniformCauchySeqOn.tendstoUniformlyOn_of_tendsto
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "TendstoUniformlyOn", "UniformCauchySeqOn" ]
A uniformly Cauchy sequence converges uniformly to its limit
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOnFilter.mono_left {p'' : Filter ι} (hf : UniformCauchySeqOnFilter F p p') (hp : p'' ≤ p) : UniformCauchySeqOnFilter F p'' p'
fun u hu => (hf u hu).filter_mono (p'.prod_mono_left (Filter.prod_mono hp hp))
theorem
UniformCauchySeqOnFilter.mono_left
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "Filter.prod_mono", "UniformCauchySeqOnFilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOnFilter.mono_right {p'' : Filter α} (hf : UniformCauchySeqOnFilter F p p') (hp : p'' ≤ p') : UniformCauchySeqOnFilter F p p''
fun u hu => have := (hf u hu).filter_mono ((p ×ˢ p).prod_mono_right hp) this.mono (by simp)
theorem
UniformCauchySeqOnFilter.mono_right
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "UniformCauchySeqOnFilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.mono (hf : UniformCauchySeqOn F p s) (hss' : s' ⊆ s) : UniformCauchySeqOn F p s'
by rw [uniformCauchySeqOn_iff_uniformCauchySeqOnFilter] at hf ⊢ exact hf.mono_right (le_principal_iff.mpr <| mem_principal.mpr hss')
theorem
UniformCauchySeqOn.mono
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "UniformCauchySeqOn", "uniformCauchySeqOn_iff_uniformCauchySeqOnFilter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOnFilter.comp {γ : Type*} (hf : UniformCauchySeqOnFilter F p p') (g : γ → α) : UniformCauchySeqOnFilter (fun n => F n ∘ g) p (p'.comap g)
fun u hu => by obtain ⟨pa, hpa, pb, hpb, hpapb⟩ := eventually_prod_iff.mp (hf u hu) rw [eventually_prod_iff] refine ⟨pa, hpa, pb ∘ g, ?_, fun hx _ hy => hpapb hx hy⟩ exact eventually_comap.mpr (hpb.mono fun x hx y hy => by simp only [hx, hy, Function.comp_apply])
theorem
UniformCauchySeqOnFilter.comp
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "UniformCauchySeqOnFilter" ]
Composing on the right by a function preserves uniform Cauchy sequences
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.comp {γ : Type*} (hf : UniformCauchySeqOn F p s) (g : γ → α) : UniformCauchySeqOn (fun n => F n ∘ g) p (g ⁻¹' s)
by rw [uniformCauchySeqOn_iff_uniformCauchySeqOnFilter] at hf ⊢ simpa only [UniformCauchySeqOn, comap_principal] using hf.comp g
theorem
UniformCauchySeqOn.comp
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "UniformCauchySeqOn", "uniformCauchySeqOn_iff_uniformCauchySeqOnFilter" ]
Composing on the right by a function preserves uniform Cauchy sequences
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformContinuous.comp_uniformCauchySeqOn [UniformSpace γ] {g : β → γ} (hg : UniformContinuous g) (hf : UniformCauchySeqOn F p s) : UniformCauchySeqOn (fun n => g ∘ F n) p s
fun _u hu => hf _ (hg hu)
theorem
UniformContinuous.comp_uniformCauchySeqOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "UniformCauchySeqOn", "UniformContinuous", "UniformSpace" ]
Composing on the left by a uniformly continuous function preserves uniform Cauchy sequences
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.prodMap {ι' α' β' : Type*} [UniformSpace β'] {F' : ι' → α' → β'} {p' : Filter ι'} {s' : Set α'} (h : UniformCauchySeqOn F p s) (h' : UniformCauchySeqOn F' p' s') : UniformCauchySeqOn (fun i : ι × ι' => Prod.map (F i.1) (F' i.2)) (p ×ˢ p') (s ×ˢ s')
by intro u hu rw [uniformity_prod_eq_prod, mem_map, mem_prod_iff] at hu obtain ⟨v, hv, w, hw, hvw⟩ := hu simp_rw [mem_prod, and_imp, Prod.forall, Prod.map_apply] rw [← Set.image_subset_iff] at hvw apply (tendsto_swap4_prod.eventually ((h v hv).prod_mk (h' w hw))).mono intro x hx a b ha hb exact hvw ⟨_, ...
theorem
UniformCauchySeqOn.prodMap
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "Set", "Set.image_subset_iff", "UniformCauchySeqOn", "UniformSpace", "uniformity_prod_eq_prod" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.prod {ι' β' : Type*} [UniformSpace β'] {F' : ι' → α → β'} {p' : Filter ι'} (h : UniformCauchySeqOn F p s) (h' : UniformCauchySeqOn F' p' s) : UniformCauchySeqOn (fun (i : ι × ι') a => (F i.fst a, F' i.snd a)) (p ×ˢ p') s
(congr_arg _ s.inter_self).mp ((h.prodMap h').comp fun a => (a, a))
theorem
UniformCauchySeqOn.prod
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "UniformCauchySeqOn", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.prod' {β' : Type*} [UniformSpace β'] {F' : ι → α → β'} (h : UniformCauchySeqOn F p s) (h' : UniformCauchySeqOn F' p s) : UniformCauchySeqOn (fun (i : ι) a => (F i a, F' i a)) p s
fun u hu => have hh : Tendsto (fun x : ι => (x, x)) p (p ×ˢ p) := tendsto_diag (hh.prodMap hh).eventually ((h.prod h') u hu)
theorem
UniformCauchySeqOn.prod'
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "UniformCauchySeqOn", "UniformSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.cauchy_map [hp : NeBot p] (hf : UniformCauchySeqOn F p s) (hx : x ∈ s) : Cauchy (map (fun i => F i x) p)
by simp only [cauchy_map_iff, hp, true_and] intro u hu rw [mem_map] filter_upwards [hf u hu] with p hp using hp x hx
theorem
UniformCauchySeqOn.cauchy_map
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Cauchy", "UniformCauchySeqOn", "cauchy_map_iff" ]
If a sequence of functions is uniformly Cauchy on a set, then the values at each point form a Cauchy sequence.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformCauchySeqOn.cauchySeq [Nonempty ι] [SemilatticeSup ι] (hf : UniformCauchySeqOn F atTop s) (hx : x ∈ s) : CauchySeq fun i ↦ F i x
hf.cauchy_map (hp := atTop_neBot) hx
theorem
UniformCauchySeqOn.cauchySeq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "CauchySeq", "SemilatticeSup", "UniformCauchySeqOn" ]
If a sequence of functions is uniformly Cauchy on a set, then the values at each point form a Cauchy sequence. See `UniformCauchySeqOn.cauchy_map` for the non-`atTop` case.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendstoUniformlyOn_of_seq_tendstoUniformlyOn {l : Filter ι} [l.IsCountablyGenerated] (h : ∀ u : ℕ → ι, Tendsto u atTop l → TendstoUniformlyOn (fun n => F (u n)) f atTop s) : TendstoUniformlyOn F f l s
by rw [tendstoUniformlyOn_iff_tendsto, tendsto_iff_seq_tendsto] intro u hu rw [tendsto_prod_iff'] at hu specialize h (fun n => (u n).fst) hu.1 rw [tendstoUniformlyOn_iff_tendsto] at h exact h.comp (tendsto_id.prodMk hu.2)
theorem
tendstoUniformlyOn_of_seq_tendstoUniformlyOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "TendstoUniformlyOn", "tendstoUniformlyOn_iff_tendsto" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TendstoUniformlyOn.seq_tendstoUniformlyOn {l : Filter ι} (h : TendstoUniformlyOn F f l s) (u : ℕ → ι) (hu : Tendsto u atTop l) : TendstoUniformlyOn (fun n => F (u n)) f atTop s
by rw [tendstoUniformlyOn_iff_tendsto] at h ⊢ exact h.comp ((hu.comp tendsto_fst).prodMk tendsto_snd)
theorem
TendstoUniformlyOn.seq_tendstoUniformlyOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "TendstoUniformlyOn", "tendstoUniformlyOn_iff_tendsto" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendstoUniformlyOn_iff_seq_tendstoUniformlyOn {l : Filter ι} [l.IsCountablyGenerated] : TendstoUniformlyOn F f l s ↔ ∀ u : ℕ → ι, Tendsto u atTop l → TendstoUniformlyOn (fun n => F (u n)) f atTop s
⟨TendstoUniformlyOn.seq_tendstoUniformlyOn, tendstoUniformlyOn_of_seq_tendstoUniformlyOn⟩
theorem
tendstoUniformlyOn_iff_seq_tendstoUniformlyOn
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "TendstoUniformlyOn" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendstoUniformly_iff_seq_tendstoUniformly {l : Filter ι} [l.IsCountablyGenerated] : TendstoUniformly F f l ↔ ∀ u : ℕ → ι, Tendsto u atTop l → TendstoUniformly (fun n => F (u n)) f atTop
by simp_rw [← tendstoUniformlyOn_univ] exact tendstoUniformlyOn_iff_seq_tendstoUniformlyOn
theorem
tendstoUniformly_iff_seq_tendstoUniformly
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Filter", "TendstoUniformly", "tendstoUniformlyOn_iff_seq_tendstoUniformlyOn", "tendstoUniformlyOn_univ" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TendstoUniformlyOnFilter.tendsto_of_eventually_tendsto (h1 : TendstoUniformlyOnFilter F f p p') (h2 : ∀ᶠ i in p, Tendsto (F i) p' (𝓝 (L i))) (h3 : Tendsto L p (𝓝 ℓ)) : Tendsto f p' (𝓝 ℓ)
by rw [tendsto_nhds_left] intro s hs rw [mem_map, Set.preimage, ← eventually_iff] obtain ⟨t, ht, hts⟩ := comp3_mem_uniformity hs have p1 : ∀ᶠ i in p, (L i, ℓ) ∈ t := tendsto_nhds_left.mp h3 ht have p2 : ∀ᶠ i in p, ∀ᶠ x in p', (F i x, L i) ∈ t := by filter_upwards [h2] with i h2 using tendsto_nhds_left.m...
theorem
TendstoUniformlyOnFilter.tendsto_of_eventually_tendsto
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "Set.preimage", "TendstoUniformlyOnFilter", "comp3_mem_uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
TendstoUniformly.tendsto_of_eventually_tendsto (h1 : TendstoUniformly F f p) (h2 : ∀ᶠ i in p, Tendsto (F i) p' (𝓝 (L i))) (h3 : Tendsto L p (𝓝 ℓ)) : Tendsto f p' (𝓝 ℓ)
(h1.tendstoUniformlyOnFilter.mono_right le_top).tendsto_of_eventually_tendsto h2 h3
theorem
TendstoUniformly.tendsto_of_eventually_tendsto
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergence.lean
[]
[ "TendstoUniformly", "le_top" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformFun (α β : Type*)
α → β
def
UniformFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
The type of functions from `α` to `β` equipped with the uniform structure and topology of uniform convergence. We denote it `α →ᵤ β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformOnFun (α β : Type*) (_ : Set (Set α))
α → β @[inherit_doc] scoped[UniformConvergence] notation:25 α " →ᵤ " β:0 => UniformFun α β @[inherit_doc] scoped[UniformConvergence] notation:25 α " →ᵤ[" 𝔖 "] " β:0 => UniformOnFun α β 𝔖
def
UniformOnFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun" ]
The type of functions from `α` to `β` equipped with the uniform structure and topology of uniform convergence on some family `𝔖` of subsets of `α`. We denote it `α →ᵤ[𝔖] β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformFun.ofFun : (α → β) ≃ (α →ᵤ β)
⟨fun x => x, fun x => x, fun _ => rfl, fun _ => rfl⟩
def
UniformFun.ofFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
Reinterpret `f : α → β` as an element of `α →ᵤ β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformOnFun.ofFun (𝔖) : (α → β) ≃ (α →ᵤ[𝔖] β)
⟨fun x => x, fun x => x, fun _ => rfl, fun _ => rfl⟩
def
UniformOnFun.ofFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
Reinterpret `f : α → β` as an element of `α →ᵤ[𝔖] β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformFun.toFun : (α →ᵤ β) ≃ (α → β)
UniformFun.ofFun.symm
def
UniformFun.toFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
Reinterpret `f : α →ᵤ β` as an element of `α → β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformOnFun.toFun (𝔖) : (α →ᵤ[𝔖] β) ≃ (α → β)
(UniformOnFun.ofFun 𝔖).symm
def
UniformOnFun.toFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformOnFun.ofFun", "symm" ]
Reinterpret `f : α →ᵤ[𝔖] β` as an element of `α → β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformFun.toFun_ofFun (f : α → β) : toFun (ofFun f) = f
rfl
lemma
UniformFun.toFun_ofFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformFun.ofFun_toFun (f : α →ᵤ β) : ofFun (toFun f) = f
rfl
lemma
UniformFun.ofFun_toFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformOnFun.toFun_ofFun (f : α → β) : toFun 𝔖 (ofFun 𝔖 f) = f
rfl
lemma
UniformOnFun.toFun_ofFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
UniformOnFun.ofFun_toFun (f : α →ᵤ[𝔖] β) : ofFun 𝔖 (toFun 𝔖 f) = f
rfl
lemma
UniformOnFun.ofFun_toFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gen (V : Set (β × β)) : Set ((α →ᵤ β) × (α →ᵤ β))
{ uv : (α →ᵤ β) × (α →ᵤ β) | ∀ x, (toFun uv.1 x, toFun uv.2 x) ∈ V }
def
UniformFun.gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set" ]
Basis sets for the uniformity of uniform convergence: `gen α β V` is the set of pairs `(f, g)` of functions `α →ᵤ β` such that `∀ x, (f x, g x) ∈ V`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isBasis_gen (𝓑 : Filter <| β × β) : IsBasis (fun V : Set (β × β) => V ∈ 𝓑) (UniformFun.gen α β)
⟨⟨univ, univ_mem⟩, @fun U V hU hV => ⟨U ∩ V, inter_mem hU hV, fun _ huv => ⟨fun x => (huv x).left, fun x => (huv x).right⟩⟩⟩
theorem
UniformFun.isBasis_gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Filter", "Set", "UniformFun.gen" ]
If `𝓕` is a filter on `β × β`, then the set of all `UniformFun.gen α β V` for `V ∈ 𝓕` is a filter basis on `(α →ᵤ β) × (α →ᵤ β)`. This will only be applied to `𝓕 = 𝓤 β` when `β` is equipped with a `UniformSpace` structure, but it is useful to define it for any filter in order to be able to state that it has a lower...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
basis (𝓕 : Filter <| β × β) : FilterBasis ((α →ᵤ β) × (α →ᵤ β))
(UniformFun.isBasis_gen α β 𝓕).filterBasis
def
UniformFun.basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Filter", "FilterBasis", "UniformFun.isBasis_gen" ]
For `𝓕 : Filter (β × β)`, this is the set of all `UniformFun.gen α β V` for `V ∈ 𝓕` as a bundled `FilterBasis` over `(α →ᵤ β) × (α →ᵤ β)`. This will only be applied to `𝓕 = 𝓤 β` when `β` is equipped with a `UniformSpace` structure, but it is useful to define it for any filter in order to be able to state that it ha...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
filter (𝓕 : Filter <| β × β) : Filter ((α →ᵤ β) × (α →ᵤ β))
(UniformFun.basis α β 𝓕).filter
def
UniformFun.filter
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Filter", "UniformFun.basis" ]
For `𝓕 : Filter (β × β)`, this is the filter generated by the filter basis `UniformFun.basis α β 𝓕`. For `𝓕 = 𝓤 β`, this will be the uniformity of uniform convergence on `α`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
phi (α β : Type*) (uvx : ((α →ᵤ β) × (α →ᵤ β)) × α) : β × β
(uvx.fst.fst uvx.2, uvx.1.2 uvx.2)
def
UniformFun.phi
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gc : GaloisConnection lowerAdjoint fun 𝓕 => UniformFun.filter α β 𝓕
by intro 𝓐 𝓕 symm calc 𝓐 ≤ UniformFun.filter α β 𝓕 ↔ (UniformFun.basis α β 𝓕).sets ⊆ 𝓐.sets := by rw [UniformFun.filter, ← FilterBasis.generate, le_generate_iff] _ ↔ ∀ U ∈ 𝓕, UniformFun.gen α β U ∈ 𝓐 := image_subset_iff _ ↔ ∀ U ∈ 𝓕, { uv | ∀ x, (uv, x) ∈ { t : ((α →ᵤ β) × (α →...
theorem
UniformFun.gc
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Filter", "FilterBasis.generate", "GaloisConnection", "UniformFun.basis", "UniformFun.filter", "UniformFun.gen", "symm" ]
The function `UniformFun.filter α β : Filter (β × β) → Filter ((α →ᵤ β) × (α →ᵤ β))` has a lower adjoint `l` (in the sense of `GaloisConnection`). The exact definition of `l` is not interesting; we will only use that it exists (in `UniformFun.mono` and `UniformFun.iInf_eq`) and that `l (Filter.map (Prod.map f f) 𝓕) = ...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformCore : UniformSpace.Core (α →ᵤ β)
UniformSpace.Core.mkOfBasis (UniformFun.basis α β (𝓤 β)) (fun _ ⟨_, hV, hVU⟩ _ => hVU ▸ fun _ => refl_mem_uniformity hV) (fun _ ⟨V, hV, hVU⟩ => hVU ▸ ⟨UniformFun.gen α β (Prod.swap ⁻¹' V), ⟨Prod.swap ⁻¹' V, tendsto_swap_uniformity hV, rfl⟩, fun _ huv x => huv x⟩) fun _ ⟨_, hV, hVU⟩ ...
def
UniformFun.uniformCore
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.basis", "UniformSpace.Core", "UniformSpace.Core.mkOfBasis", "comp_mem_uniformity_sets", "refl_mem_uniformity", "tendsto_swap_uniformity" ]
Core of the uniform structure of uniform convergence.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformSpace : UniformSpace (α →ᵤ β)
UniformSpace.ofCore (UniformFun.uniformCore α β)
instance
UniformFun.uniformSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.uniformCore", "UniformSpace", "UniformSpace.ofCore" ]
Uniform structure of uniform convergence, declared as an instance on `α →ᵤ β`. We will denote it `𝒰(α, β, uβ)` in the rest of this file.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
topologicalSpace : TopologicalSpace (α →ᵤ β)
inferInstance
instance
UniformFun.topologicalSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "TopologicalSpace" ]
Topology of uniform convergence, declared as an instance on `α →ᵤ β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_uniformity : (𝓤 (α →ᵤ β)).HasBasis (· ∈ 𝓤 β) (UniformFun.gen α β)
(UniformFun.isBasis_gen α β (𝓤 β)).hasBasis
theorem
UniformFun.hasBasis_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.gen", "UniformFun.isBasis_gen" ]
By definition, the uniformity of `α →ᵤ β` admits the family `{(f, g) | ∀ x, (f x, g x) ∈ V}` for `V ∈ 𝓤 β` as a filter basis.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_uniformity_of_basis {ι : Sort*} {p : ι → Prop} {s : ι → Set (β × β)} (h : (𝓤 β).HasBasis p s) : (𝓤 (α →ᵤ β)).HasBasis p (UniformFun.gen α β ∘ s)
(UniformFun.hasBasis_uniformity α β).to_hasBasis (fun _ hU => let ⟨i, hi, hiU⟩ := h.mem_iff.mp hU ⟨i, hi, fun _ huv x => hiU (huv x)⟩) fun i hi => ⟨s i, h.mem_of_mem hi, subset_rfl⟩
theorem
UniformFun.hasBasis_uniformity_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.gen", "UniformFun.hasBasis_uniformity" ]
The uniformity of `α →ᵤ β` admits the family `{(f, g) | ∀ x, (f x, g x) ∈ V}` for `V ∈ 𝓑` as a filter basis, for any basis `𝓑` of `𝓤 β` (in the case `𝓑 = (𝓤 β).as_basis` this is true by definition).
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_nhds_of_basis (f) {p : ι → Prop} {s : ι → Set (β × β)} (h : HasBasis (𝓤 β) p s) : (𝓝 f).HasBasis p fun i => { g | (f, g) ∈ UniformFun.gen α β (s i) }
nhds_basis_uniformity' (UniformFun.hasBasis_uniformity_of_basis α β h)
theorem
UniformFun.hasBasis_nhds_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.gen", "UniformFun.hasBasis_uniformity_of_basis", "nhds_basis_uniformity'" ]
For `f : α →ᵤ β`, `𝓝 f` admits the family `{g | ∀ x, (f x, g x) ∈ V}` for `V ∈ 𝓑` as a filter basis, for any basis `𝓑` of `𝓤 β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_nhds (f) : (𝓝 f).HasBasis (fun V => V ∈ 𝓤 β) fun V => { g | (f, g) ∈ UniformFun.gen α β V }
UniformFun.hasBasis_nhds_of_basis α β f (Filter.basis_sets _)
theorem
UniformFun.hasBasis_nhds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Filter.basis_sets", "UniformFun.gen", "UniformFun.hasBasis_nhds_of_basis" ]
For `f : α →ᵤ β`, `𝓝 f` admits the family `{g | ∀ x, (f x, g x) ∈ V}` for `V ∈ 𝓤 β` as a filter basis.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_eval (x : α) : UniformContinuous (Function.eval x ∘ toFun : (α →ᵤ β) → β)
by change _ ≤ _ rw [map_le_iff_le_comap, (UniformFun.hasBasis_uniformity α β).le_basis_iff ((𝓤 _).basis_sets.comap _)] exact fun U hU => ⟨U, hU, fun uv huv => huv x⟩
theorem
UniformFun.uniformContinuous_eval
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Function.eval", "UniformContinuous", "UniformFun.hasBasis_uniformity" ]
Evaluation at a fixed point is uniformly continuous on `α →ᵤ β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
mem_gen {β} {f g : α →ᵤ β} {V : Set (β × β)} : (f, g) ∈ UniformFun.gen α β V ↔ ∀ x, (toFun f x, toFun g x) ∈ V
.rfl
lemma
UniformFun.mem_gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.gen" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
mono : Monotone (@UniformFun.uniformSpace α γ)
fun _ _ hu => (UniformFun.gc α γ).monotone_u hu
theorem
UniformFun.mono
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Monotone", "UniformFun.gc", "UniformFun.uniformSpace" ]
If `u₁` and `u₂` are two uniform structures on `γ` and `u₁ ≤ u₂`, then `𝒰(α, γ, u₁) ≤ 𝒰(α, γ, u₂)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
iInf_eq {u : ι → UniformSpace γ} : 𝒰(α, γ, (⨅ i, u i)) = ⨅ i, 𝒰(α, γ, u i)
by -- This follows directly from the fact that the upper adjoint in a Galois connection maps -- infimas to infimas. ext : 1 change UniformFun.filter α γ 𝓤[⨅ i, u i] = 𝓤[⨅ i, 𝒰(α, γ, u i)] rw [iInf_uniformity, iInf_uniformity] exact (UniformFun.gc α γ).u_iInf
theorem
UniformFun.iInf_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.filter", "UniformFun.gc", "UniformSpace", "iInf_uniformity" ]
If `u` is a family of uniform structures on `γ`, then `𝒰(α, γ, (⨅ i, u i)) = ⨅ i, 𝒰(α, γ, u i)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
inf_eq {u₁ u₂ : UniformSpace γ} : 𝒰(α, γ, u₁ ⊓ u₂) = 𝒰(α, γ, u₁) ⊓ 𝒰(α, γ, u₂)
by -- This follows directly from the fact that the upper adjoint in a Galois connection maps -- infimas to infimas. rw [inf_eq_iInf, inf_eq_iInf, UniformFun.iInf_eq] refine iInf_congr fun i => ?_ cases i <;> rfl
theorem
UniformFun.inf_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.iInf_eq", "UniformSpace" ]
If `u₁` and `u₂` are two uniform structures on `γ`, then `𝒰(α, γ, u₁ ⊓ u₂) = 𝒰(α, γ, u₁) ⊓ 𝒰(α, γ, u₂)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
postcomp_isUniformInducing [UniformSpace γ] {f : γ → β} (hf : IsUniformInducing f) : IsUniformInducing (ofFun ∘ (f ∘ ·) ∘ toFun : (α →ᵤ γ) → α →ᵤ β)
⟨((UniformFun.hasBasis_uniformity _ _).comap _).eq_of_same_basis <| UniformFun.hasBasis_uniformity_of_basis _ _ (hf.basis_uniformity (𝓤 β).basis_sets)⟩
lemma
UniformFun.postcomp_isUniformInducing
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "IsUniformInducing", "UniformFun.hasBasis_uniformity", "UniformFun.hasBasis_uniformity_of_basis", "UniformSpace", "comap" ]
Post-composition by a uniform inducing function is a uniform inducing function for the uniform structures of uniform convergence. More precisely, if `f : γ → β` is uniform inducing, then `(f ∘ ·) : (α →ᵤ γ) → (α →ᵤ β)` is uniform inducing.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
postcomp_isUniformEmbedding [UniformSpace γ] {f : γ → β} (hf : IsUniformEmbedding f) : IsUniformEmbedding (ofFun ∘ (f ∘ ·) ∘ toFun : (α →ᵤ γ) → α →ᵤ β)
where toIsUniformInducing := UniformFun.postcomp_isUniformInducing hf.isUniformInducing injective _ _ H := funext fun _ ↦ hf.injective (congrFun H _)
theorem
UniformFun.postcomp_isUniformEmbedding
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "IsUniformEmbedding", "UniformFun.postcomp_isUniformInducing", "UniformSpace" ]
Post-composition by a uniform embedding is a uniform embedding for the uniform structures of uniform convergence. More precisely, if `f : γ → β` is a uniform embedding, then `(f ∘ ·) : (α →ᵤ γ) → (α →ᵤ β)` is a uniform embedding.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
comap_eq {f : γ → β} : 𝒰(α, γ, ‹UniformSpace β›.comap f) = 𝒰(α, β, _).comap (f ∘ ·)
by letI : UniformSpace γ := .comap f ‹_› exact (UniformFun.postcomp_isUniformInducing (f := f) ⟨rfl⟩).comap_uniformSpace.symm
theorem
UniformFun.comap_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.postcomp_isUniformInducing", "UniformSpace", "comap" ]
If `u` is a uniform structures on `β` and `f : γ → β`, then `𝒰(α, γ, comap f u) = comap (fun g ↦ f ∘ g) 𝒰(α, γ, u₁)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
postcomp_uniformContinuous [UniformSpace γ] {f : γ → β} (hf : UniformContinuous f) : UniformContinuous (ofFun ∘ (f ∘ ·) ∘ toFun : (α →ᵤ γ) → α →ᵤ β)
by -- This is a direct consequence of `UniformFun.comap_eq` refine uniformContinuous_iff_le_comap.mpr ?_ calc 𝒰(α, γ, _) ≤ 𝒰(α, γ, ‹UniformSpace β›.comap f) := UniformFun.mono (uniformContinuous_iff_le_comap.mp hf) _ = 𝒰(α, β, _).comap (f ∘ ·) := by exact UniformFun.comap_eq
theorem
UniformFun.postcomp_uniformContinuous
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformContinuous", "UniformFun.comap_eq", "UniformFun.mono", "UniformSpace", "comap" ]
Post-composition by a uniformly continuous function is uniformly continuous on `α →ᵤ β`. More precisely, if `f : γ → β` is uniformly continuous, then `(fun g ↦ f ∘ g) : (α →ᵤ γ) → (α →ᵤ β)` is uniformly continuous.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
congrRight [UniformSpace γ] (e : γ ≃ᵤ β) : (α →ᵤ γ) ≃ᵤ (α →ᵤ β)
{ Equiv.piCongrRight fun _ => e.toEquiv with uniformContinuous_toFun := UniformFun.postcomp_uniformContinuous e.uniformContinuous uniformContinuous_invFun := UniformFun.postcomp_uniformContinuous e.symm.uniformContinuous }
def
UniformFun.congrRight
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Equiv.piCongrRight", "UniformFun.postcomp_uniformContinuous", "UniformSpace" ]
Turn a uniform isomorphism `γ ≃ᵤ β` into a uniform isomorphism `(α →ᵤ γ) ≃ᵤ (α →ᵤ β)` by post-composing.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
precomp_uniformContinuous {f : γ → α} : UniformContinuous fun g : α →ᵤ β => ofFun (toFun g ∘ f)
by -- Here we simply go back to filter bases. rw [UniformContinuous, (UniformFun.hasBasis_uniformity α β).tendsto_iff (UniformFun.hasBasis_uniformity γ β)] exact fun U hU => ⟨U, hU, fun uv huv x => huv (f x)⟩
theorem
UniformFun.precomp_uniformContinuous
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformContinuous", "UniformFun.hasBasis_uniformity" ]
Pre-composition by any function is uniformly continuous for the uniform structures of uniform convergence. More precisely, for any `f : γ → α`, the function `(· ∘ f) : (α →ᵤ β) → (γ →ᵤ β)` is uniformly continuous.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
congrLeft (e : γ ≃ α) : (γ →ᵤ β) ≃ᵤ (α →ᵤ β)
where toEquiv := e.arrowCongr (.refl _) uniformContinuous_toFun := UniformFun.precomp_uniformContinuous uniformContinuous_invFun := UniformFun.precomp_uniformContinuous
def
UniformFun.congrLeft
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.precomp_uniformContinuous", "refl" ]
Turn a bijection `γ ≃ α` into a uniform isomorphism `(γ →ᵤ β) ≃ᵤ (α →ᵤ β)` by pre-composing.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_toFun : UniformContinuous (toFun : (α →ᵤ β) → α → β)
by -- By definition of the product uniform structure, this is just `uniform_continuous_eval`. rw [uniformContinuous_pi] intro x exact uniformContinuous_eval β x
theorem
UniformFun.uniformContinuous_toFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformContinuous", "uniformContinuous_pi" ]
The natural map `UniformFun.toFun` from `α →ᵤ β` to `α → β` is uniformly continuous. In other words, the uniform structure of uniform convergence is finer than that of pointwise convergence, aka the product uniform structure.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
tendsto_iff_tendstoUniformly {F : ι → α →ᵤ β} {f : α →ᵤ β} : Tendsto F p (𝓝 f) ↔ TendstoUniformly (toFun ∘ F) (toFun f) p
by rw [(UniformFun.hasBasis_nhds α β f).tendsto_right_iff, TendstoUniformly] simp only [mem_setOf, UniformFun.gen, Function.comp_def]
theorem
UniformFun.tendsto_iff_tendstoUniformly
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "TendstoUniformly", "UniformFun.gen", "UniformFun.hasBasis_nhds" ]
The topology of uniform convergence indeed gives the same notion of convergence as `TendstoUniformly`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformEquivProdArrow [UniformSpace γ] : (α →ᵤ β × γ) ≃ᵤ (α →ᵤ β) × (α →ᵤ γ)
-- Denote `φ` this bijection. We want to show that -- `comap φ (𝒰(α, β, uβ) × 𝒰(α, γ, uγ)) = 𝒰(α, β × γ, uβ × uγ)`. -- But `uβ × uγ` is defined as `comap fst uβ ⊓ comap snd uγ`, so we just have to apply -- `UniformFun.inf_eq` and `UniformFun.comap_eq`, which leaves us to check -- that some square commutes. ...
def
UniformFun.uniformEquivProdArrow
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Equiv.arrowProdEquivProdArrow", "Equiv.toUniformEquivOfIsUniformInducing", "UniformFun", "UniformFun.comap_eq", "UniformFun.inf_eq", "UniformSpace", "UniformSpace.comap", "UniformSpace.comap_comap", "UniformSpace.comap_inf", "comap", "instUniformSpaceProd", "symm", "uniformity_comap" ]
The natural bijection between `α → β × γ` and `(α → β) × (α → γ)`, upgraded to a uniform isomorphism between `α →ᵤ β × γ` and `(α →ᵤ β) × (α →ᵤ γ)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformEquivPiComm : UniformEquiv (α →ᵤ ∀ i, δ i) (∀ i, α →ᵤ δ i)
-- Denote `φ` this bijection. We want to show that -- `comap φ (Π i, 𝒰(α, δ i, uδ i)) = 𝒰(α, (Π i, δ i), (Π i, uδ i))`. -- But `Π i, uδ i` is defined as `⨅ i, comap (eval i) (uδ i)`, so we just have to apply -- `UniformFun.iInf_eq` and `UniformFun.comap_eq`, which leaves us to check -- that some squar...
def
UniformFun.uniformEquivPiComm
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Equiv.piComm", "Equiv.toUniformEquivOfIsUniformInducing", "Function.swap", "Pi.uniformSpace", "UniformEquiv", "UniformFun.comap_eq", "UniformFun.iInf_eq", "UniformSpace.comap_comap", "UniformSpace.comap_iInf", "UniformSpace.ofCoreEq_toCore", "comap", "uniformity_comap" ]
The natural bijection between `α → Π i, δ i` and `Π i, α → δ i`, upgraded to a uniform isomorphism between `α →ᵤ (Π i, δ i)` and `Π i, α →ᵤ δ i`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isClosed_setOf_continuous [TopologicalSpace α] : IsClosed {f : α →ᵤ β | Continuous (toFun f)}
by refine isClosed_iff_forall_filter.2 fun f u _ hu huf ↦ ?_ rw [← tendsto_id', UniformFun.tendsto_iff_tendstoUniformly] at huf exact huf.continuous <| Eventually.frequently (le_principal_iff.mp hu)
theorem
UniformFun.isClosed_setOf_continuous
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Continuous", "IsClosed", "TopologicalSpace", "UniformFun.tendsto_iff_tendstoUniformly" ]
The set of continuous functions is closed in the uniform convergence topology. This is a simple wrapper over `TendstoUniformly.continuous`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformSpace_eq_inf_precomp_of_cover {δ₁ δ₂ : Type*} (φ₁ : δ₁ → α) (φ₂ : δ₂ → α) (h_cover : range φ₁ ∪ range φ₂ = univ) : 𝒰(α, β, _) = .comap (ofFun ∘ (· ∘ φ₁) ∘ toFun) 𝒰(δ₁, β, _) ⊓ .comap (ofFun ∘ (· ∘ φ₂) ∘ toFun) 𝒰(δ₂, β, _)
by ext : 1 refine le_antisymm (le_inf ?_ ?_) ?_ · exact tendsto_iff_comap.mp UniformFun.precomp_uniformContinuous · exact tendsto_iff_comap.mp UniformFun.precomp_uniformContinuous · refine (UniformFun.hasBasis_uniformity δ₁ β |>.comap _).inf (UniformFun.hasBasis_uniformity δ₂ β |>.comap _) ...
theorem
UniformFun.uniformSpace_eq_inf_precomp_of_cover
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.hasBasis_uniformity", "UniformFun.precomp_uniformContinuous", "comap", "le_antisymm" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformSpace_eq_iInf_precomp_of_cover {δ : ι → Type*} (φ : Π i, δ i → α) (h_cover : ∃ I : Set ι, I.Finite ∧ ⋃ i ∈ I, range (φ i) = univ) : 𝒰(α, β, _) = ⨅ i, .comap (ofFun ∘ (· ∘ φ i) ∘ toFun) 𝒰(δ i, β, _)
by ext : 1 simp_rw [iInf_uniformity, uniformity_comap] refine le_antisymm (le_iInf fun i ↦ tendsto_iff_comap.mp UniformFun.precomp_uniformContinuous) ?_ rcases h_cover with ⟨I, I_finite, I_cover⟩ refine HasBasis.iInf (fun i : ι ↦ UniformFun.hasBasis_uniformity (δ i) β |>.comap _) |>.le_basis_iff (Unifor...
theorem
UniformFun.uniformSpace_eq_iInf_precomp_of_cover
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.hasBasis_uniformity", "UniformFun.precomp_uniformContinuous", "comap", "iInf_uniformity", "le_antisymm", "uniformity_comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gen (𝔖) (S : Set α) (V : Set (β × β)) : Set ((α →ᵤ[𝔖] β) × (α →ᵤ[𝔖] β))
{ uv : (α →ᵤ[𝔖] β) × (α →ᵤ[𝔖] β) | ∀ x ∈ S, (toFun 𝔖 uv.1 x, toFun 𝔖 uv.2 x) ∈ V }
def
UniformOnFun.gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set" ]
Basis sets for the uniformity of `𝔖`-convergence: for `S : Set α` and `V : Set (β × β)`, `gen 𝔖 S V` is the set of pairs `(f, g)` of functions `α →ᵤ[𝔖] β` such that `∀ x ∈ S, (f x, g x) ∈ V`. Note that the family `𝔖 : Set (Set α)` is only used to specify which type alias of `α → β` to use here.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gen_eq_preimage_restrict {𝔖} (S : Set α) (V : Set (β × β)) : UniformOnFun.gen 𝔖 S V = Prod.map (S.restrict ∘ UniformFun.toFun) (S.restrict ∘ UniformFun.toFun) ⁻¹' UniformFun.gen S β V
by ext uv exact ⟨fun h ⟨x, hx⟩ => h x hx, fun h x hx => h ⟨x, hx⟩⟩
theorem
UniformOnFun.gen_eq_preimage_restrict
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.gen", "UniformFun.toFun", "UniformOnFun.gen" ]
For `S : Set α` and `V : Set (β × β)`, we have `UniformOnFun.gen 𝔖 S V = (S.restrict × S.restrict) ⁻¹' (UniformFun.gen S β V)`. This is the crucial fact for proving that the family `UniformOnFun.gen S V` for `S ∈ 𝔖` and `V ∈ 𝓤 β` is indeed a basis for the uniformity `α →ᵤ[𝔖] β` endowed with `𝒱(α, β, 𝔖, uβ)` the u...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gen_mono {𝔖} {S S' : Set α} {V V' : Set (β × β)} (hS : S' ⊆ S) (hV : V ⊆ V') : UniformOnFun.gen 𝔖 S V ⊆ UniformOnFun.gen 𝔖 S' V'
fun _uv h x hx => hV (h x <| hS hx)
theorem
UniformOnFun.gen_mono
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformOnFun.gen" ]
`UniformOnFun.gen` is antitone in the first argument and monotone in the second.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isBasis_gen (𝔖 : Set (Set α)) (h : 𝔖.Nonempty) (h' : DirectedOn (· ⊆ ·) 𝔖) (𝓑 : FilterBasis <| β × β) : IsBasis (fun SV : Set α × Set (β × β) => SV.1 ∈ 𝔖 ∧ SV.2 ∈ 𝓑) fun SV => UniformOnFun.gen 𝔖 SV.1 SV.2
⟨h.prod 𝓑.nonempty, fun {U₁V₁ U₂V₂} h₁ h₂ => let ⟨U₃, hU₃, hU₁₃, hU₂₃⟩ := h' U₁V₁.1 h₁.1 U₂V₂.1 h₂.1 let ⟨V₃, hV₃, hV₁₂₃⟩ := 𝓑.inter_sets h₁.2 h₂.2 ⟨⟨U₃, V₃⟩, ⟨⟨hU₃, hV₃⟩, fun _ H => ⟨fun x hx => (hV₁₂₃ <| H x <| hU₁₃ hx).1, fun x hx => (hV₁₂₃ <| H x <| hU₂₃ hx).2⟩⟩⟩⟩
theorem
UniformOnFun.isBasis_gen
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "DirectedOn", "FilterBasis", "Set", "UniformOnFun.gen" ]
If `𝔖 : Set (Set α)` is nonempty and directed and `𝓑` is a filter basis on `β × β`, then the family `UniformOnFun.gen 𝔖 S V` for `S ∈ 𝔖` and `V ∈ 𝓑` is a filter basis on `(α →ᵤ[𝔖] β) × (α →ᵤ[𝔖] β)`. We will show in `has_basis_uniformity_of_basis` that, if `𝓑` is a basis for `𝓤 β`, then the corresponding filter...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformSpace : UniformSpace (α →ᵤ[𝔖] β)
⨅ (s : Set α) (_ : s ∈ 𝔖), .comap (UniformFun.ofFun ∘ s.restrict ∘ UniformOnFun.toFun 𝔖) 𝒰(s, β, _)
instance
UniformOnFun.uniformSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.ofFun", "UniformOnFun.toFun", "UniformSpace", "comap" ]
Uniform structure of `𝔖`-convergence, i.e uniform convergence on the elements of `𝔖`, declared as an instance on `α →ᵤ[𝔖] β`. It is defined as the infimum, for `S ∈ 𝔖`, of the pullback by `S.restrict`, the map of restriction to `S`, of the uniform structure `𝒰(s, β, uβ)` on `↥S →ᵤ β`. We will denote it `𝒱(α, β, �...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
topologicalSpace : TopologicalSpace (α →ᵤ[𝔖] β)
𝒱(α, β, 𝔖, _).toTopologicalSpace
instance
UniformOnFun.topologicalSpace
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "TopologicalSpace" ]
Topology of `𝔖`-convergence, i.e uniform convergence on the elements of `𝔖`, declared as an instance on `α →ᵤ[𝔖] β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
topologicalSpace_eq : UniformOnFun.topologicalSpace α β 𝔖 = ⨅ (s : Set α) (_ : s ∈ 𝔖), TopologicalSpace.induced (UniformFun.ofFun ∘ s.restrict ∘ toFun 𝔖) (UniformFun.topologicalSpace s β)
by simp only [UniformOnFun.topologicalSpace, UniformSpace.toTopologicalSpace_iInf] rfl
theorem
UniformOnFun.topologicalSpace_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "TopologicalSpace.induced", "UniformFun.ofFun", "UniformFun.topologicalSpace", "UniformOnFun.topologicalSpace", "UniformSpace.toTopologicalSpace_iInf" ]
The topology of `𝔖`-convergence is the infimum, for `S ∈ 𝔖`, of topology induced by the map of `S.restrict : (α →ᵤ[𝔖] β) → (↥S →ᵤ β)` of restriction to `S`, where `↥S →ᵤ β` is endowed with the topology of uniform convergence.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_uniformity_of_basis_aux₁ {p : ι → Prop} {s : ι → Set (β × β)} (hb : HasBasis (𝓤 β) p s) (S : Set α) : (@uniformity (α →ᵤ[𝔖] β) ((UniformFun.uniformSpace S β).comap S.restrict)).HasBasis p fun i => UniformOnFun.gen 𝔖 S (s i)
by simp_rw [UniformOnFun.gen_eq_preimage_restrict, uniformity_comap] exact (UniformFun.hasBasis_uniformity_of_basis S β hb).comap _
theorem
UniformOnFun.hasBasis_uniformity_of_basis_aux₁
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.hasBasis_uniformity_of_basis", "UniformFun.uniformSpace", "UniformOnFun.gen", "UniformOnFun.gen_eq_preimage_restrict", "comap", "uniformity", "uniformity_comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_uniformity_of_basis_aux₂ (h : DirectedOn (· ⊆ ·) 𝔖) {p : ι → Prop} {s : ι → Set (β × β)} (hb : HasBasis (𝓤 β) p s) : DirectedOn ((fun s : Set α => (UniformFun.uniformSpace s β).comap (s.restrict : (α →ᵤ β) → s →ᵤ β)) ⁻¹'o GE.ge) 𝔖
h.mono fun _ _ hst => ((UniformOnFun.hasBasis_uniformity_of_basis_aux₁ α β 𝔖 hb _).le_basis_iff (UniformOnFun.hasBasis_uniformity_of_basis_aux₁ α β 𝔖 hb _)).mpr fun V hV => ⟨V, hV, UniformOnFun.gen_mono hst subset_rfl⟩
theorem
UniformOnFun.hasBasis_uniformity_of_basis_aux₂
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "DirectedOn", "Set", "UniformFun.uniformSpace", "UniformOnFun.gen_mono", "UniformOnFun.hasBasis_uniformity_of_basis_aux₁", "comap" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_uniformity_of_basis (h : 𝔖.Nonempty) (h' : DirectedOn (· ⊆ ·) 𝔖) {p : ι → Prop} {s : ι → Set (β × β)} (hb : HasBasis (𝓤 β) p s) : (𝓤 (α →ᵤ[𝔖] β)).HasBasis (fun Si : Set α × ι => Si.1 ∈ 𝔖 ∧ p Si.2) fun Si => UniformOnFun.gen 𝔖 Si.1 (s Si.2)
by simp only [iInf_uniformity] exact hasBasis_biInf_of_directed h (fun S => UniformOnFun.gen 𝔖 S ∘ s) _ (fun S _hS => UniformOnFun.hasBasis_uniformity_of_basis_aux₁ α β 𝔖 hb S) (UniformOnFun.hasBasis_uniformity_of_basis_aux₂ α β 𝔖 h' hb)
theorem
UniformOnFun.hasBasis_uniformity_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "DirectedOn", "Set", "UniformOnFun.gen", "UniformOnFun.hasBasis_uniformity_of_basis_aux₁", "UniformOnFun.hasBasis_uniformity_of_basis_aux₂", "iInf_uniformity" ]
If `𝔖 : Set (Set α)` is nonempty and directed and `𝓑` is a filter basis of `𝓤 β`, then the uniformity of `α →ᵤ[𝔖] β` admits the family `{(f, g) | ∀ x ∈ S, (f x, g x) ∈ V}` for `S ∈ 𝔖` and `V ∈ 𝓑` as a filter basis.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_uniformity (h : 𝔖.Nonempty) (h' : DirectedOn (· ⊆ ·) 𝔖) : (𝓤 (α →ᵤ[𝔖] β)).HasBasis (fun SV : Set α × Set (β × β) => SV.1 ∈ 𝔖 ∧ SV.2 ∈ 𝓤 β) fun SV => UniformOnFun.gen 𝔖 SV.1 SV.2
UniformOnFun.hasBasis_uniformity_of_basis α β 𝔖 h h' (𝓤 β).basis_sets
theorem
UniformOnFun.hasBasis_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "DirectedOn", "Set", "UniformOnFun.gen", "UniformOnFun.hasBasis_uniformity_of_basis" ]
If `𝔖 : Set (Set α)` is nonempty and directed, then the uniformity of `α →ᵤ[𝔖] β` admits the family `{(f, g) | ∀ x ∈ S, (f x, g x) ∈ V}` for `S ∈ 𝔖` and `V ∈ 𝓤 β` as a filter basis.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_uniformity_of_covering_of_basis {ι ι' : Type*} [Nonempty ι] {t : ι → Set α} {p : ι' → Prop} {V : ι' → Set (β × β)} (ht : ∀ i, t i ∈ 𝔖) (hdir : Directed (· ⊆ ·) t) (hex : ∀ s ∈ 𝔖, ∃ i, s ⊆ t i) (hb : HasBasis (𝓤 β) p V) : (𝓤 (α →ᵤ[𝔖] β)).HasBasis (fun i : ι × ι' ↦ p i.2) fun i ↦ UniformOn...
by have hne : 𝔖.Nonempty := (range_nonempty t).mono (range_subset_iff.2 ht) have hd : DirectedOn (· ⊆ ·) 𝔖 := fun s₁ hs₁ s₂ hs₂ ↦ by rcases hex s₁ hs₁, hex s₂ hs₂ with ⟨⟨i₁, his₁⟩, i₂, his₂⟩ rcases hdir i₁ i₂ with ⟨i, hi₁, hi₂⟩ exact ⟨t i, ht _, his₁.trans hi₁, his₂.trans hi₂⟩ refine (UniformOnFun.h...
theorem
UniformOnFun.hasBasis_uniformity_of_covering_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Directed", "DirectedOn", "Set", "UniformOnFun.gen", "UniformOnFun.gen_mono", "UniformOnFun.hasBasis_uniformity_of_basis" ]
Let `t i` be a nonempty directed subfamily of `𝔖` such that every `s ∈ 𝔖` is included in some `t i`. Let `V` bounded by `p` be a basis of entourages of `β`. Then `UniformOnFun.gen 𝔖 (t i) (V j)` bounded by `p j` is a basis of entourages of `α →ᵤ[𝔖] β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasAntitoneBasis_uniformity {ι : Type*} [Preorder ι] [IsDirectedOrder ι] {t : ι → Set α} {V : ι → Set (β × β)} (ht : ∀ n, t n ∈ 𝔖) (hmono : Monotone t) (hex : ∀ s ∈ 𝔖, ∃ n, s ⊆ t n) (hb : HasAntitoneBasis (𝓤 β) V) : (𝓤 (α →ᵤ[𝔖] β)).HasAntitoneBasis fun n ↦ UniformOnFun.gen 𝔖 (t n) (V n)
by have := hb.nonempty refine ⟨(UniformOnFun.hasBasis_uniformity_of_covering_of_basis 𝔖 ht hmono.directed_le hex hb.1).to_hasBasis ?_ fun i _ ↦ ⟨(i, i), trivial, Subset.rfl⟩, ?_⟩ · rintro ⟨k, l⟩ - rcases directed_of (· ≤ ·) k l with ⟨n, hkn, hln⟩ exact ⟨n, trivial, UniformOnFun.gen_mono (hmono hkn) (...
theorem
UniformOnFun.hasAntitoneBasis_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "IsDirectedOrder", "Monotone", "Preorder", "Set", "UniformOnFun.gen", "UniformOnFun.gen_mono", "UniformOnFun.hasBasis_uniformity_of_covering_of_basis", "directed_of" ]
If `t n` is a monotone sequence of sets in `𝔖` such that each `s ∈ 𝔖` is included in some `t n` and `V n` is an antitone basis of entourages of `β`, then `UniformOnFun.gen 𝔖 (t n) (V n)` is an antitone basis of entourages of `α →ᵤ[𝔖] β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isCountablyGenerated_uniformity [IsCountablyGenerated (𝓤 β)] {t : ℕ → Set α} (ht : ∀ n, t n ∈ 𝔖) (hmono : Monotone t) (hex : ∀ s ∈ 𝔖, ∃ n, s ⊆ t n) : IsCountablyGenerated (𝓤 (α →ᵤ[𝔖] β))
let ⟨_V, hV⟩ := exists_antitone_basis (𝓤 β) (UniformOnFun.hasAntitoneBasis_uniformity 𝔖 ht hmono hex hV).isCountablyGenerated
theorem
UniformOnFun.isCountablyGenerated_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Monotone", "Set", "UniformOnFun.hasAntitoneBasis_uniformity" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_nhds_of_basis (f : α →ᵤ[𝔖] β) (h : 𝔖.Nonempty) (h' : DirectedOn (· ⊆ ·) 𝔖) {p : ι → Prop} {s : ι → Set (β × β)} (hb : HasBasis (𝓤 β) p s) : (𝓝 f).HasBasis (fun Si : Set α × ι => Si.1 ∈ 𝔖 ∧ p Si.2) fun Si => { g | (g, f) ∈ UniformOnFun.gen 𝔖 Si.1 (s Si.2) }
letI : UniformSpace (α → β) := UniformOnFun.uniformSpace α β 𝔖 nhds_basis_uniformity (UniformOnFun.hasBasis_uniformity_of_basis α β 𝔖 h h' hb)
theorem
UniformOnFun.hasBasis_nhds_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "DirectedOn", "Set", "UniformOnFun.gen", "UniformOnFun.hasBasis_uniformity_of_basis", "UniformOnFun.uniformSpace", "UniformSpace", "nhds_basis_uniformity" ]
For `f : α →ᵤ[𝔖] β`, where `𝔖 : Set (Set α)` is nonempty and directed, `𝓝 f` admits the family `{g | ∀ x ∈ S, (f x, g x) ∈ V}` for `S ∈ 𝔖` and `V ∈ 𝓑` as a filter basis, for any basis `𝓑` of `𝓤 β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hasBasis_nhds (f : α →ᵤ[𝔖] β) (h : 𝔖.Nonempty) (h' : DirectedOn (· ⊆ ·) 𝔖) : (𝓝 f).HasBasis (fun SV : Set α × Set (β × β) => SV.1 ∈ 𝔖 ∧ SV.2 ∈ 𝓤 β) fun SV => { g | (g, f) ∈ UniformOnFun.gen 𝔖 SV.1 SV.2 }
UniformOnFun.hasBasis_nhds_of_basis α β 𝔖 f h h' (Filter.basis_sets _)
theorem
UniformOnFun.hasBasis_nhds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "DirectedOn", "Filter.basis_sets", "Set", "UniformOnFun.gen", "UniformOnFun.hasBasis_nhds_of_basis" ]
For `f : α →ᵤ[𝔖] β`, where `𝔖 : Set (Set α)` is nonempty and directed, `𝓝 f` admits the family `{g | ∀ x ∈ S, (f x, g x) ∈ V}` for `S ∈ 𝔖` and `V ∈ 𝓤 β` as a filter basis.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_restrict (h : s ∈ 𝔖) : UniformContinuous (UniformFun.ofFun ∘ (s.restrict : (α → β) → s → β) ∘ toFun 𝔖)
by change _ ≤ _ simp only [map_le_iff_le_comap, iInf_uniformity] exact iInf₂_le s h
theorem
UniformOnFun.uniformContinuous_restrict
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformContinuous", "UniformFun.ofFun", "iInf_uniformity" ]
If `S ∈ 𝔖`, then the restriction to `S` is a uniformly continuous map from `α →ᵤ[𝔖] β` to `↥S →ᵤ β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isUniformEmbedding_toFun_finite : IsUniformEmbedding (toFun _ : (α →ᵤ[{s | s.Finite}] β) → (α → β))
by refine ⟨⟨?_⟩, Function.injective_id⟩ simp_rw [Pi.uniformity, comap_iInf, comap_comap] refine HasBasis.ext (HasBasis.iInf' fun i ↦ (basis_sets _).comap _) (UniformOnFun.hasBasis_uniformity α β _ ⟨∅, finite_empty⟩ (directedOn_of_sup_mem fun _ _ ↦ .union)) (fun ⟨S, U⟩ ⟨hS, hU⟩ ↦ ⟨⟨S, ⋂ x ∈ S, U x⟩, ...
theorem
UniformOnFun.isUniformEmbedding_toFun_finite
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "IsUniformEmbedding", "Pi.uniformity", "UniformOnFun.hasBasis_uniformity", "comap", "directedOn_of_sup_mem" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isEmbedding_toFun_finite : IsEmbedding (toFun _ : (α →ᵤ[{s | s.Finite}] β) → (α → β))
(isUniformEmbedding_toFun_finite α β).isEmbedding
theorem
UniformOnFun.isEmbedding_toFun_finite
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformity_eq_of_basis {ι : Sort*} {p : ι → Prop} {V : ι → Set (β × β)} (h : (𝓤 β).HasBasis p V) : 𝓤 (α →ᵤ[𝔖] β) = ⨅ s ∈ 𝔖, ⨅ (i) (_ : p i), 𝓟 (UniformOnFun.gen 𝔖 s (V i))
by simp_rw [iInf_uniformity, uniformity_comap, (UniformFun.hasBasis_uniformity_of_basis _ _ h).eq_biInf, comap_iInf, comap_principal, Function.comp_apply, UniformFun.gen, Subtype.forall, UniformOnFun.gen, preimage_setOf_eq, Prod.map_fst, Prod.map_snd, Function.comp_apply, UniformFun.toFun_ofFun, restrict_...
theorem
UniformOnFun.uniformity_eq_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.gen", "UniformFun.hasBasis_uniformity_of_basis", "UniformFun.toFun_ofFun", "UniformOnFun.gen", "iInf_uniformity", "uniformity_comap" ]
A version of `UniformOnFun.hasBasis_uniformity_of_basis` with weaker conclusion and weaker assumptions. We make no assumptions about the set `𝔖` but conclude only that the uniformity is equal to some indexed infimum.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformity_eq : 𝓤 (α →ᵤ[𝔖] β) = ⨅ s ∈ 𝔖, ⨅ V ∈ 𝓤 β, 𝓟 (UniformOnFun.gen 𝔖 s V)
UniformOnFun.uniformity_eq_of_basis _ _ (𝓤 β).basis_sets
theorem
UniformOnFun.uniformity_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformOnFun.gen", "UniformOnFun.uniformity_eq_of_basis" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gen_mem_uniformity (hs : s ∈ 𝔖) {V : Set (β × β)} (hV : V ∈ 𝓤 β) : UniformOnFun.gen 𝔖 s V ∈ 𝓤 (α →ᵤ[𝔖] β)
by rw [UniformOnFun.uniformity_eq] apply_rules [mem_iInf_of_mem, mem_principal_self]
theorem
UniformOnFun.gen_mem_uniformity
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformOnFun.gen", "UniformOnFun.uniformity_eq" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
nhds_eq_of_basis {ι : Sort*} {p : ι → Prop} {V : ι → Set (β × β)} (h : (𝓤 β).HasBasis p V) (f : α →ᵤ[𝔖] β) : 𝓝 f = ⨅ s ∈ 𝔖, ⨅ (i) (_ : p i), 𝓟 {g | ∀ x ∈ s, (toFun 𝔖 f x, toFun 𝔖 g x) ∈ V i}
by simp_rw [nhds_eq_comap_uniformity, UniformOnFun.uniformity_eq_of_basis _ _ h, comap_iInf, comap_principal, UniformOnFun.gen, preimage_setOf_eq]
theorem
UniformOnFun.nhds_eq_of_basis
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformOnFun.gen", "UniformOnFun.uniformity_eq_of_basis", "nhds_eq_comap_uniformity" ]
A version of `UniformOnFun.hasBasis_nhds_of_basis` with weaker conclusion and weaker assumptions. We make no assumptions about the set `𝔖` but conclude only that the neighbourhoods filter is equal to some indexed infimum.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
nhds_eq (f : α →ᵤ[𝔖] β) : 𝓝 f = ⨅ s ∈ 𝔖, ⨅ V ∈ 𝓤 β, 𝓟 {g | ∀ x ∈ s, (toFun 𝔖 f x, toFun 𝔖 g x) ∈ V}
UniformOnFun.nhds_eq_of_basis _ _ (𝓤 β).basis_sets f
theorem
UniformOnFun.nhds_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformOnFun.nhds_eq_of_basis" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gen_mem_nhds (f : α →ᵤ[𝔖] β) (hs : s ∈ 𝔖) {V : Set (β × β)} (hV : V ∈ 𝓤 β) : {g | ∀ x ∈ s, (toFun 𝔖 f x, toFun 𝔖 g x) ∈ V} ∈ 𝓝 f
by rw [UniformOnFun.nhds_eq] apply_rules [mem_iInf_of_mem, mem_principal_self]
theorem
UniformOnFun.gen_mem_nhds
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformOnFun.nhds_eq" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_ofUniformFun : UniformContinuous fun f : α →ᵤ β ↦ ofFun 𝔖 (UniformFun.toFun f)
by simp only [UniformContinuous, UniformOnFun.uniformity_eq, tendsto_iInf, tendsto_principal, (UniformFun.hasBasis_uniformity _ _).eventually_iff] exact fun _ _ U hU ↦ ⟨U, hU, fun f hf x _ ↦ hf x⟩
theorem
UniformOnFun.uniformContinuous_ofUniformFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformContinuous", "UniformFun.hasBasis_uniformity", "UniformFun.toFun", "UniformOnFun.uniformity_eq" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformEquivUniformFun (h : univ ∈ 𝔖) : (α →ᵤ[𝔖] β) ≃ᵤ (α →ᵤ β)
where toFun f := UniformFun.ofFun <| toFun _ f invFun f := ofFun _ <| UniformFun.toFun f uniformContinuous_toFun := by simp only [UniformContinuous, (UniformFun.hasBasis_uniformity _ _).tendsto_right_iff] intro U hU filter_upwards [UniformOnFun.gen_mem_uniformity _ _ h hU] with f hf x using hf x (mem_...
def
UniformOnFun.uniformEquivUniformFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformContinuous", "UniformFun.hasBasis_uniformity", "UniformFun.ofFun", "UniformFun.toFun", "UniformOnFun.gen_mem_uniformity" ]
The uniformity on `α →ᵤ[𝔖] β` is the same as the uniformity on `α →ᵤ β`, provided that `Set.univ ∈ 𝔖`. Here we formulate it as a `UniformEquiv`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_ofFun_toFun (𝔗 : Set (Set α)) (h : ∀ s ∈ 𝔖, ∃ T ⊆ 𝔗, T.Finite ∧ s ⊆ ⋃₀ T) : UniformContinuous (ofFun 𝔗 ∘ toFun 𝔖 : (α →ᵤ[𝔗] β) → α →ᵤ[𝔖] β)
by simp only [UniformContinuous, UniformOnFun.uniformity_eq, iInf₂_comm (ι₂ := Set (β × β))] refine tendsto_iInf_iInf fun V ↦ tendsto_iInf_iInf fun hV ↦ ?_ simp only [tendsto_iInf, tendsto_principal, Filter.Eventually, mem_biInf_principal] intro s hs obtain ⟨T, hT𝔗, hT, hsT⟩ := h s hs refine ⟨T, hT, hT𝔗, ...
lemma
UniformOnFun.uniformContinuous_ofFun_toFun
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Filter.Eventually", "Set", "Set.mem_iInter", "Set.mem_setOf_eq", "UniformContinuous", "UniformOnFun.gen", "UniformOnFun.uniformity_eq" ]
If `𝔖` and `𝔗` are families of sets in `α`, then the identity map `(α →ᵤ[𝔗] β) → (α →ᵤ[𝔖] β)` is uniformly continuous if every `s ∈ 𝔖` is contained in a finite union of elements of `𝔗`. With more API around `Order.Ideal`, this could be phrased in that language instead.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
mono ⦃u₁ u₂ : UniformSpace γ⦄ (hu : u₁ ≤ u₂) ⦃𝔖₁ 𝔖₂ : Set (Set α)⦄ (h𝔖 : 𝔖₂ ⊆ 𝔖₁) : 𝒱(α, γ, 𝔖₁, u₁) ≤ 𝒱(α, γ, 𝔖₂, u₂)
calc 𝒱(α, γ, 𝔖₁, u₁) ≤ 𝒱(α, γ, 𝔖₂, u₁) := iInf_le_iInf_of_subset h𝔖 _ ≤ 𝒱(α, γ, 𝔖₂, u₂) := iInf₂_mono fun _i _hi => UniformSpace.comap_mono <| UniformFun.mono hu
theorem
UniformOnFun.mono
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Set", "UniformFun.mono", "UniformSpace", "UniformSpace.comap_mono" ]
Let `u₁`, `u₂` be two uniform structures on `γ` and `𝔖₁ 𝔖₂ : Set (Set α)`. If `u₁ ≤ u₂` and `𝔖₂ ⊆ 𝔖₁` then `𝒱(α, γ, 𝔖₁, u₁) ≤ 𝒱(α, γ, 𝔖₂, u₂)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_eval_of_mem {x : α} (hxs : x ∈ s) (hs : s ∈ 𝔖) : UniformContinuous ((Function.eval x : (α → β) → β) ∘ toFun 𝔖)
(UniformFun.uniformContinuous_eval β (⟨x, hxs⟩ : s)).comp (UniformOnFun.uniformContinuous_restrict α β 𝔖 hs)
theorem
UniformOnFun.uniformContinuous_eval_of_mem
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Function.eval", "UniformContinuous", "UniformFun.uniformContinuous_eval", "UniformOnFun.uniformContinuous_restrict" ]
If `x : α` is in some `S ∈ 𝔖`, then evaluation at `x` is uniformly continuous on `α →ᵤ[𝔖] β`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_eval_of_mem_sUnion {x : α} (hx : x ∈ ⋃₀ 𝔖) : UniformContinuous ((Function.eval x : (α → β) → β) ∘ toFun 𝔖)
let ⟨_s, hs, hxs⟩ := hx uniformContinuous_eval_of_mem _ _ hxs hs
theorem
UniformOnFun.uniformContinuous_eval_of_mem_sUnion
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Function.eval", "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
uniformContinuous_eval (h : ⋃₀ 𝔖 = univ) (x : α) : UniformContinuous ((Function.eval x : (α → β) → β) ∘ toFun 𝔖)
uniformContinuous_eval_of_mem_sUnion _ _ <| h.symm ▸ mem_univ _
theorem
UniformOnFun.uniformContinuous_eval
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "Function.eval", "UniformContinuous" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
iInf_eq {u : ι → UniformSpace γ} : 𝒱(α, γ, 𝔖, ⨅ i, u i) = ⨅ i, 𝒱(α, γ, 𝔖, u i)
by simp_rw [UniformOnFun.uniformSpace, UniformFun.iInf_eq, UniformSpace.comap_iInf] rw [iInf_comm] exact iInf_congr fun s => iInf_comm
theorem
UniformOnFun.iInf_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.iInf_eq", "UniformOnFun.uniformSpace", "UniformSpace", "UniformSpace.comap_iInf" ]
If `u` is a family of uniform structures on `γ`, then `𝒱(α, γ, 𝔖, (⨅ i, u i)) = ⨅ i, 𝒱(α, γ, 𝔖, u i)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
inf_eq {u₁ u₂ : UniformSpace γ} : 𝒱(α, γ, 𝔖, u₁ ⊓ u₂) = 𝒱(α, γ, 𝔖, u₁) ⊓ 𝒱(α, γ, 𝔖, u₂)
by rw [inf_eq_iInf, inf_eq_iInf, UniformOnFun.iInf_eq] refine iInf_congr fun i => ?_ cases i <;> rfl
theorem
UniformOnFun.inf_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformOnFun.iInf_eq", "UniformSpace" ]
If `u₁` and `u₂` are two uniform structures on `γ`, then `𝒱(α, γ, 𝔖, u₁ ⊓ u₂) = 𝒱(α, γ, 𝔖, u₁) ⊓ 𝒱(α, γ, 𝔖, u₂)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
comap_eq {f : γ → β} : 𝒱(α, γ, 𝔖, ‹UniformSpace β›.comap f) = 𝒱(α, β, 𝔖, _).comap (f ∘ ·)
by -- We reduce this to `UniformFun.comap_eq` using the fact that `comap` distributes -- on `iInf`. simp_rw [UniformOnFun.uniformSpace, UniformSpace.comap_iInf, UniformFun.comap_eq, ← UniformSpace.comap_comap] -- By definition, `∀ S ∈ 𝔖, (f ∘ —) ∘ S.restrict = S.restrict ∘ (f ∘ —)`. rfl
theorem
UniformOnFun.comap_eq
Topology.UniformSpace
Mathlib/Topology/UniformSpace/UniformConvergenceTopology.lean
[]
[ "UniformFun.comap_eq", "UniformOnFun.uniformSpace", "UniformSpace.comap_comap", "UniformSpace.comap_iInf", "comap" ]
If `u` is a uniform structure on `β` and `f : γ → β`, then `𝒱(α, γ, 𝔖, comap f u) = comap (fun g ↦ f ∘ g) 𝒱(α, γ, 𝔖, u₁)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319