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UniformEquicontinuous.closure' {A : Set Y} {u : Y → β → α} (hA : UniformEquicontinuous (u ∘ (↑) : A → β → α)) (hu : Continuous u) : UniformEquicontinuous (u ∘ (↑) : closure A → β → α) := by rw [← uniformEquicontinuousOn_univ] at hA ⊢ exact hA.closure' (Pi.continuous_restrict _ |>.comp hu)
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
UniformEquicontinuous.closure'
If a set of functions is uniformly equicontinuous, the same is true for its closure in *any* topology for which evaluation at any point is continuous. Since this will be applied to `DFunLike` types, we state it for any topological space with a map to `β → α` satisfying the right continuity conditions. See also `Set.UniformEquicontinuous.closure` for a more familiar statement.
protected Set.UniformEquicontinuous.closure {A : Set <| β → α} (hA : A.UniformEquicontinuous) : (closure A).UniformEquicontinuous := UniformEquicontinuous.closure' (u := id) hA continuous_id
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Set.UniformEquicontinuous.closure
If a set of functions is uniformly equicontinuous, its closure for the product topology is also uniformly equicontinuous.
protected Set.UniformEquicontinuousOn.closure {A : Set <| β → α} {S : Set β} (hA : A.UniformEquicontinuousOn S) : (closure A).UniformEquicontinuousOn S := UniformEquicontinuousOn.closure' (u := id) hA (Pi.continuous_restrict _) /- Implementation note: The following lemma (as well as all the following variations) could theoretically be deduced from the "closure" statements above. For example, we could do: ```lean
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Set.UniformEquicontinuousOn.closure
If a set of functions is uniformly equicontinuous on a set `S`, its closure for the product topology is also uniformly equicontinuous. This would also be true for the coarser topology of pointwise convergence on `S`, see `UniformEquicontinuousOn.closure'`.
Filter.Tendsto.continuousAt_of_equicontinuousAt {l : Filter ι} [l.NeBot] {F : ι → X → α} {f : X → α} {x₀ : X} (h₁ : Tendsto F l (𝓝 f)) (h₂ : EquicontinuousAt F x₀) : ContinuousAt f x₀ := (equicontinuousAt_iff_range.mp h₂).closure.continuousAt ⟨f, mem_closure_of_tendsto h₁ <| Eventually.of_forall mem_range_self⟩
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.continuousAt_of_equicontinuousAt
null
Filter.Tendsto.uniformContinuous_of_uniformEquicontinuous {l : Filter ι} [l.NeBot] {F : ι → β → α} {f : β → α} (h₁ : Tendsto F l (𝓝 f)) (h₂ : UniformEquicontinuous F) : UniformContinuous f := (uniformEquicontinuous_iff_range.mp h₂).closure.uniformContinuous ⟨f, mem_closure_of_tendsto h₁ <| Eventually.of_forall mem_range_self⟩ ``` Unfortunately, the proofs get painful when dealing with the relative case as one needs to change the ambient topology. So it turns out to be easier to re-do the proof by hand. -/
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.uniformContinuous_of_uniformEquicontinuous
null
Filter.Tendsto.continuousWithinAt_of_equicontinuousWithinAt {l : Filter ι} [l.NeBot] {F : ι → X → α} {f : X → α} {S : Set X} {x₀ : X} (h₁ : ∀ x ∈ S, Tendsto (F · x) l (𝓝 (f x))) (h₂ : Tendsto (F · x₀) l (𝓝 (f x₀))) (h₃ : EquicontinuousWithinAt F S x₀) : ContinuousWithinAt f S x₀ := by intro U hU; rw [mem_map] rcases UniformSpace.mem_nhds_iff.mp hU with ⟨V, hV, hVU⟩ rcases mem_uniformity_isClosed hV with ⟨W, hW, hWclosed, hWV⟩ filter_upwards [h₃ W hW, eventually_mem_nhdsWithin] with x hx hxS using hVU <| ball_mono hWV (f x₀) <| hWclosed.mem_of_tendsto (h₂.prodMk_nhds (h₁ x hxS)) <| Eventually.of_forall hx
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.continuousWithinAt_of_equicontinuousWithinAt
If `𝓕 : ι → X → α` tends to `f : X → α` *pointwise on `S ∪ {x₀} : Set X`* along some nontrivial filter, and if the family `𝓕` is equicontinuous at `x₀ : X` within `S`, then the limit is continuous at `x₀` within `S`.
Filter.Tendsto.continuousAt_of_equicontinuousAt {l : Filter ι} [l.NeBot] {F : ι → X → α} {f : X → α} {x₀ : X} (h₁ : Tendsto F l (𝓝 f)) (h₂ : EquicontinuousAt F x₀) : ContinuousAt f x₀ := by rw [← continuousWithinAt_univ, ← equicontinuousWithinAt_univ, tendsto_pi_nhds] at * exact continuousWithinAt_of_equicontinuousWithinAt (fun x _ ↦ h₁ x) (h₁ x₀) h₂
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.continuousAt_of_equicontinuousAt
If `𝓕 : ι → X → α` tends to `f : X → α` *pointwise* along some nontrivial filter, and if the family `𝓕` is equicontinuous at some `x₀ : X`, then the limit is continuous at `x₀`.
Filter.Tendsto.continuous_of_equicontinuous {l : Filter ι} [l.NeBot] {F : ι → X → α} {f : X → α} (h₁ : Tendsto F l (𝓝 f)) (h₂ : Equicontinuous F) : Continuous f := continuous_iff_continuousAt.mpr fun x => h₁.continuousAt_of_equicontinuousAt (h₂ x)
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.continuous_of_equicontinuous
If `𝓕 : ι → X → α` tends to `f : X → α` *pointwise* along some nontrivial filter, and if the family `𝓕` is equicontinuous, then the limit is continuous.
Filter.Tendsto.continuousOn_of_equicontinuousOn {l : Filter ι} [l.NeBot] {F : ι → X → α} {f : X → α} {S : Set X} (h₁ : ∀ x ∈ S, Tendsto (F · x) l (𝓝 (f x))) (h₂ : EquicontinuousOn F S) : ContinuousOn f S := fun x hx ↦ Filter.Tendsto.continuousWithinAt_of_equicontinuousWithinAt h₁ (h₁ x hx) (h₂ x hx)
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.continuousOn_of_equicontinuousOn
If `𝓕 : ι → X → α` tends to `f : X → α` *pointwise on `S : Set X`* along some nontrivial filter, and if the family `𝓕` is equicontinuous, then the limit is continuous on `S`.
Filter.Tendsto.uniformContinuousOn_of_uniformEquicontinuousOn {l : Filter ι} [l.NeBot] {F : ι → β → α} {f : β → α} {S : Set β} (h₁ : ∀ x ∈ S, Tendsto (F · x) l (𝓝 (f x))) (h₂ : UniformEquicontinuousOn F S) : UniformContinuousOn f S := by intro U hU; rw [mem_map] rcases mem_uniformity_isClosed hU with ⟨V, hV, hVclosed, hVU⟩ filter_upwards [h₂ V hV, mem_inf_of_right (mem_principal_self _)] rintro ⟨x, y⟩ hxy ⟨hxS, hyS⟩ exact hVU <| hVclosed.mem_of_tendsto ((h₁ x hxS).prodMk_nhds (h₁ y hyS)) <| Eventually.of_forall hxy
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.uniformContinuousOn_of_uniformEquicontinuousOn
If `𝓕 : ι → β → α` tends to `f : β → α` *pointwise on `S : Set β`* along some nontrivial filter, and if the family `𝓕` is uniformly equicontinuous on `S`, then the limit is uniformly continuous on `S`.
Filter.Tendsto.uniformContinuous_of_uniformEquicontinuous {l : Filter ι} [l.NeBot] {F : ι → β → α} {f : β → α} (h₁ : Tendsto F l (𝓝 f)) (h₂ : UniformEquicontinuous F) : UniformContinuous f := by rw [← uniformContinuousOn_univ, ← uniformEquicontinuousOn_univ, tendsto_pi_nhds] at * exact uniformContinuousOn_of_uniformEquicontinuousOn (fun x _ ↦ h₁ x) h₂
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Filter.Tendsto.uniformContinuous_of_uniformEquicontinuous
If `𝓕 : ι → β → α` tends to `f : β → α` *pointwise* along some nontrivial filter, and if the family `𝓕` is uniformly equicontinuous, then the limit is uniformly continuous.
EquicontinuousAt.tendsto_of_mem_closure {l : Filter ι} {F : ι → X → α} {f : X → α} {s : Set X} {x : X} {z : α} (hF : EquicontinuousAt F x) (hf : Tendsto f (𝓝[s] x) (𝓝 z)) (hs : ∀ y ∈ s, Tendsto (F · y) l (𝓝 (f y))) (hx : x ∈ closure s) : Tendsto (F · x) l (𝓝 z) := by rw [(nhds_basis_uniformity (𝓤 α).basis_sets).tendsto_right_iff] at hf ⊢ intro U hU rcases comp_comp_symm_mem_uniformity_sets hU with ⟨V, hV, hVs, hVU⟩ rw [mem_closure_iff_nhdsWithin_neBot] at hx have : ∀ᶠ y in 𝓝[s] x, y ∈ s ∧ (∀ i, (F i x, F i y) ∈ V) ∧ (f y, z) ∈ V := eventually_mem_nhdsWithin.and <| ((hF V hV).filter_mono nhdsWithin_le_nhds).and (hf V hV) rcases this.exists with ⟨y, hys, hFy, hfy⟩ filter_upwards [hs y hys (ball_mem_nhds _ hV)] with i hi exact hVU ⟨_, ⟨_, hFy i, (mem_ball_symmetry hVs).2 hi⟩, hfy⟩
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
EquicontinuousAt.tendsto_of_mem_closure
If `F : ι → X → α` is a family of functions equicontinuous at `x`, it tends to `f y` along a filter `l` for any `y ∈ s`, the limit function `f` tends to `z` along `𝓝[s] x`, and `x ∈ closure s`, then `(F · x)` tends to `z` along `l`. In some sense, this is a converse of `EquicontinuousAt.closure`.
Equicontinuous.isClosed_setOf_tendsto {l : Filter ι} {F : ι → X → α} {f : X → α} (hF : Equicontinuous F) (hf : Continuous f) : IsClosed {x | Tendsto (F · x) l (𝓝 (f x))} := closure_subset_iff_isClosed.mp fun x hx ↦ (hF x).tendsto_of_mem_closure (hf.continuousAt.mono_left inf_le_left) (fun _ ↦ id) hx
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/UniformSpace/Equicontinuity.lean
Equicontinuous.isClosed_setOf_tendsto
If `F : ι → X → α` is an equicontinuous family of functions, `f : X → α` is a continuous function, and `l` is a filter on `ι`, then `{x | Filter.Tendsto (F · x) l (𝓝 (f x))}` is a closed set.
UniformEquiv (α : Type*) (β : Type*) [UniformSpace α] [UniformSpace β] extends α ≃ β where /-- Uniform continuity of the function -/ uniformContinuous_toFun : UniformContinuous toFun /-- Uniform continuity of the inverse -/ uniformContinuous_invFun : UniformContinuous invFun
structure
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
UniformEquiv
Uniform isomorphism between `α` and `β`
protected symm (h : α ≃ᵤ β) : β ≃ᵤ α where uniformContinuous_toFun := h.uniformContinuous_invFun uniformContinuous_invFun := h.uniformContinuous_toFun toEquiv := h.toEquiv.symm
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
symm
Uniform isomorphism between `α` and `β` -/ infixl:25 " ≃ᵤ " => UniformEquiv namespace UniformEquiv variable [UniformSpace α] [UniformSpace β] [UniformSpace γ] [UniformSpace δ] theorem toEquiv_injective : Function.Injective (toEquiv : α ≃ᵤ β → α ≃ β) | ⟨e, h₁, h₂⟩, ⟨e', h₁', h₂'⟩, h => by simpa only [mk.injEq] instance : EquivLike (α ≃ᵤ β) α β where coe h := h.toEquiv inv h := h.toEquiv.symm left_inv h := h.left_inv right_inv h := h.right_inv coe_injective' _ _ H _ := toEquiv_injective <| DFunLike.ext' H @[simp] theorem uniformEquiv_mk_coe (a : Equiv α β) (b c) : (UniformEquiv.mk a b c : α → β) = a := rfl /-- Inverse of a uniform isomorphism.
Simps.apply (h : α ≃ᵤ β) : α → β := h
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
Simps.apply
See Note [custom simps projection]. We need to specify this projection explicitly in this case, because it is a composition of multiple projections.
Simps.symm_apply (h : α ≃ᵤ β) : β → α := h.symm initialize_simps_projections UniformEquiv (toFun → apply, invFun → symm_apply) @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
Simps.symm_apply
See Note [custom simps projection]
coe_toEquiv (h : α ≃ᵤ β) : ⇑h.toEquiv = h := rfl @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
coe_toEquiv
null
coe_symm_toEquiv (h : α ≃ᵤ β) : ⇑h.toEquiv.symm = h.symm := rfl @[ext]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
coe_symm_toEquiv
null
ext {h h' : α ≃ᵤ β} (H : ∀ x, h x = h' x) : h = h' := toEquiv_injective <| Equiv.ext H
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
ext
null
@[simps! -fullyApplied apply] protected refl (α : Type*) [UniformSpace α] : α ≃ᵤ α where uniformContinuous_toFun := uniformContinuous_id uniformContinuous_invFun := uniformContinuous_id toEquiv := Equiv.refl α
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
refl
Identity map as a uniform isomorphism.
protected trans (h₁ : α ≃ᵤ β) (h₂ : β ≃ᵤ γ) : α ≃ᵤ γ where uniformContinuous_toFun := h₂.uniformContinuous_toFun.comp h₁.uniformContinuous_toFun uniformContinuous_invFun := h₁.uniformContinuous_invFun.comp h₂.uniformContinuous_invFun toEquiv := Equiv.trans h₁.toEquiv h₂.toEquiv @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
trans
Composition of two uniform isomorphisms.
trans_apply (h₁ : α ≃ᵤ β) (h₂ : β ≃ᵤ γ) (a : α) : h₁.trans h₂ a = h₂ (h₁ a) := rfl @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
trans_apply
null
uniformEquiv_mk_coe_symm (a : Equiv α β) (b c) : ((UniformEquiv.mk a b c).symm : β → α) = a.symm := rfl @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
uniformEquiv_mk_coe_symm
null
refl_symm : (UniformEquiv.refl α).symm = UniformEquiv.refl α := rfl
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
refl_symm
null
protected uniformContinuous (h : α ≃ᵤ β) : UniformContinuous h := h.uniformContinuous_toFun @[continuity]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
uniformContinuous
null
protected continuous (h : α ≃ᵤ β) : Continuous h := h.uniformContinuous.continuous
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
continuous
null
protected uniformContinuous_symm (h : α ≃ᵤ β) : UniformContinuous h.symm := h.uniformContinuous_invFun @[continuity]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
uniformContinuous_symm
null
protected continuous_symm (h : α ≃ᵤ β) : Continuous h.symm := h.uniformContinuous_symm.continuous
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
continuous_symm
null
protected toHomeomorph (e : α ≃ᵤ β) : α ≃ₜ β := { e.toEquiv with continuous_toFun := e.continuous continuous_invFun := e.continuous_symm }
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
toHomeomorph
A uniform isomorphism as a homeomorphism.
toHomeomorph_apply (e : α ≃ᵤ β) : (e.toHomeomorph : α → β) = e := rfl
lemma
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
toHomeomorph_apply
null
toHomeomorph_symm_apply (e : α ≃ᵤ β) : (e.toHomeomorph.symm : β → α) = e.symm := rfl @[simp]
lemma
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
toHomeomorph_symm_apply
null
apply_symm_apply (h : α ≃ᵤ β) (x : β) : h (h.symm x) = x := h.toEquiv.apply_symm_apply x @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
apply_symm_apply
null
symm_apply_apply (h : α ≃ᵤ β) (x : α) : h.symm (h x) = x := h.toEquiv.symm_apply_apply x
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
symm_apply_apply
null
protected bijective (h : α ≃ᵤ β) : Function.Bijective h := h.toEquiv.bijective
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
bijective
null
protected injective (h : α ≃ᵤ β) : Function.Injective h := h.toEquiv.injective
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
injective
null
protected surjective (h : α ≃ᵤ β) : Function.Surjective h := h.toEquiv.surjective
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
surjective
null
changeInv (f : α ≃ᵤ β) (g : β → α) (hg : Function.RightInverse g f) : α ≃ᵤ β := have : g = f.symm := funext fun x => calc g x = f.symm (f (g x)) := (f.left_inv (g x)).symm _ = f.symm x := by rw [hg x] { toFun := f invFun := g left_inv := by convert f.left_inv right_inv := by convert f.right_inv using 1 uniformContinuous_toFun := f.uniformContinuous uniformContinuous_invFun := by convert f.symm.uniformContinuous } @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
changeInv
Change the uniform equiv `f` to make the inverse function definitionally equal to `g`.
symm_comp_self (h : α ≃ᵤ β) : (h.symm : β → α) ∘ h = id := funext h.symm_apply_apply @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
symm_comp_self
null
self_comp_symm (h : α ≃ᵤ β) : (h : α → β) ∘ h.symm = id := funext h.apply_symm_apply
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
self_comp_symm
null
range_coe (h : α ≃ᵤ β) : range h = univ := by simp
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
range_coe
null
image_symm (h : α ≃ᵤ β) : image h.symm = preimage h := funext h.symm.toEquiv.image_eq_preimage
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
image_symm
null
preimage_symm (h : α ≃ᵤ β) : preimage h.symm = image h := (funext h.toEquiv.image_eq_preimage).symm @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
preimage_symm
null
image_preimage (h : α ≃ᵤ β) (s : Set β) : h '' (h ⁻¹' s) = s := h.toEquiv.image_preimage s @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
image_preimage
null
preimage_image (h : α ≃ᵤ β) (s : Set α) : h ⁻¹' (h '' s) = s := h.toEquiv.preimage_image s
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
preimage_image
null
isUniformInducing (h : α ≃ᵤ β) : IsUniformInducing h := IsUniformInducing.of_comp h.uniformContinuous h.symm.uniformContinuous <| by simp only [symm_comp_self, IsUniformInducing.id]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
isUniformInducing
null
comap_eq (h : α ≃ᵤ β) : UniformSpace.comap h ‹_› = ‹_› := h.isUniformInducing.comap_uniformSpace
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
comap_eq
null
isUniformEmbedding (h : α ≃ᵤ β) : IsUniformEmbedding h := ⟨h.isUniformInducing, h.injective⟩
lemma
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
isUniformEmbedding
null
completeSpace_iff (h : α ≃ᵤ β) : CompleteSpace α ↔ CompleteSpace β := completeSpace_congr h.isUniformEmbedding
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
completeSpace_iff
null
noncomputable ofIsUniformEmbedding (f : α → β) (hf : IsUniformEmbedding f) : α ≃ᵤ Set.range f where uniformContinuous_toFun := hf.isUniformInducing.uniformContinuous.subtype_mk _ uniformContinuous_invFun := by rw [hf.isUniformInducing.uniformContinuous_iff, Equiv.invFun_as_coe, Equiv.self_comp_ofInjective_symm] exact uniformContinuous_subtype_val toEquiv := Equiv.ofInjective f hf.injective
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
ofIsUniformEmbedding
Uniform equiv given a uniform embedding.
setCongr {s t : Set α} (h : s = t) : s ≃ᵤ t where uniformContinuous_toFun := uniformContinuous_subtype_val.subtype_mk _ uniformContinuous_invFun := uniformContinuous_subtype_val.subtype_mk _ toEquiv := Equiv.setCongr h
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
setCongr
If two sets are equal, then they are uniformly equivalent.
prodCongr (h₁ : α ≃ᵤ β) (h₂ : γ ≃ᵤ δ) : α × γ ≃ᵤ β × δ where uniformContinuous_toFun := (h₁.uniformContinuous.comp uniformContinuous_fst).prodMk (h₂.uniformContinuous.comp uniformContinuous_snd) uniformContinuous_invFun := (h₁.symm.uniformContinuous.comp uniformContinuous_fst).prodMk (h₂.symm.uniformContinuous.comp uniformContinuous_snd) toEquiv := h₁.toEquiv.prodCongr h₂.toEquiv @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
prodCongr
Product of two uniform isomorphisms.
prodCongr_symm (h₁ : α ≃ᵤ β) (h₂ : γ ≃ᵤ δ) : (h₁.prodCongr h₂).symm = h₁.symm.prodCongr h₂.symm := rfl @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
prodCongr_symm
null
coe_prodCongr (h₁ : α ≃ᵤ β) (h₂ : γ ≃ᵤ δ) : ⇑(h₁.prodCongr h₂) = Prod.map h₁ h₂ := rfl
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
coe_prodCongr
null
prodComm : α × β ≃ᵤ β × α where uniformContinuous_toFun := uniformContinuous_snd.prodMk uniformContinuous_fst uniformContinuous_invFun := uniformContinuous_snd.prodMk uniformContinuous_fst toEquiv := Equiv.prodComm α β @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
prodComm
`α × β` is uniformly isomorphic to `β × α`.
prodComm_symm : (prodComm α β).symm = prodComm β α := rfl @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
prodComm_symm
null
coe_prodComm : ⇑(prodComm α β) = Prod.swap := rfl
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
coe_prodComm
null
prodAssoc : (α × β) × γ ≃ᵤ α × β × γ where uniformContinuous_toFun := (uniformContinuous_fst.comp uniformContinuous_fst).prodMk ((uniformContinuous_snd.comp uniformContinuous_fst).prodMk uniformContinuous_snd) uniformContinuous_invFun := (uniformContinuous_fst.prodMk (uniformContinuous_fst.comp uniformContinuous_snd)).prodMk (uniformContinuous_snd.comp uniformContinuous_snd) toEquiv := Equiv.prodAssoc α β γ
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
prodAssoc
`(α × β) × γ` is uniformly isomorphic to `α × (β × γ)`.
@[simps! -fullyApplied apply] prodPunit : α × PUnit ≃ᵤ α where toEquiv := Equiv.prodPUnit α uniformContinuous_toFun := uniformContinuous_fst uniformContinuous_invFun := uniformContinuous_id.prodMk uniformContinuous_const
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
prodPunit
`α × {*}` is uniformly isomorphic to `α`.
punitProd : PUnit × α ≃ᵤ α := (prodComm _ _).trans (prodPunit _) @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
punitProd
`{*} × α` is uniformly isomorphic to `α`.
coe_punitProd : ⇑(punitProd α) = Prod.snd := rfl
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
coe_punitProd
null
@[simps toEquiv, simps! -isSimp apply] piCongrLeft {ι ι' : Type*} {β : ι' → Type*} [∀ j, UniformSpace (β j)] (e : ι ≃ ι') : (∀ i, β (e i)) ≃ᵤ ∀ j, β j where uniformContinuous_toFun := uniformContinuous_pi.mpr <| e.forall_congr_right.mp fun i ↦ by simpa only [Equiv.toFun_as_coe, Equiv.piCongrLeft_apply_apply] using Pi.uniformContinuous_proj _ i uniformContinuous_invFun := Pi.uniformContinuous_precomp' _ e toEquiv := Equiv.piCongrLeft _ e @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongrLeft
`Equiv.piCongrLeft` as a uniform isomorphism: this is the natural isomorphism `Π i, β (e i) ≃ᵤ Π j, β j` obtained from a bijection `ι ≃ ι'`.
piCongrLeft_refl {ι : Type*} {X : ι → Type*} [∀ i, UniformSpace (X i)] : piCongrLeft (.refl ι) = .refl (∀ i, X i) := rfl @[simp]
lemma
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongrLeft_refl
null
piCongrLeft_symm_apply {ι ι' : Type*} {X : ι' → Type*} [∀ j, UniformSpace (X j)] (e : ι ≃ ι') : ⇑(piCongrLeft (β := X) e).symm = (· <| e ·) := rfl @[simp]
lemma
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongrLeft_symm_apply
null
piCongrLeft_apply_apply {ι ι' : Type*} {X : ι' → Type*} [∀ j, UniformSpace (X j)] (e : ι ≃ ι') (x : ∀ i, X (e i)) i : piCongrLeft e x (e i) = x i := Equiv.piCongrLeft_apply_apply ..
lemma
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongrLeft_apply_apply
null
@[simps! apply toEquiv] piCongrRight {ι : Type*} {β₁ β₂ : ι → Type*} [∀ i, UniformSpace (β₁ i)] [∀ i, UniformSpace (β₂ i)] (F : ∀ i, β₁ i ≃ᵤ β₂ i) : (∀ i, β₁ i) ≃ᵤ ∀ i, β₂ i where uniformContinuous_toFun := Pi.uniformContinuous_postcomp' _ fun i ↦ (F i).uniformContinuous uniformContinuous_invFun := Pi.uniformContinuous_postcomp' _ fun i ↦ (F i).symm.uniformContinuous toEquiv := Equiv.piCongrRight fun i => (F i).toEquiv @[simp]
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongrRight
`Equiv.piCongrRight` as a uniform isomorphism: this is the natural isomorphism `Π i, β₁ i ≃ᵤ Π j, β₂ i` obtained from uniform isomorphisms `β₁ i ≃ᵤ β₂ i` for each `i`.
piCongrRight_symm {ι : Type*} {β₁ β₂ : ι → Type*} [∀ i, UniformSpace (β₁ i)] [∀ i, UniformSpace (β₂ i)] (F : ∀ i, β₁ i ≃ᵤ β₂ i) : (piCongrRight F).symm = piCongrRight fun i => (F i).symm := rfl @[simp]
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongrRight_symm
null
piCongrRight_refl {ι : Type*} {X : ι → Type*} [∀ i, UniformSpace (X i)] : piCongrRight (fun i ↦ .refl (X i)) = .refl (∀ i, X i) := rfl
theorem
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongrRight_refl
null
@[simps! apply toEquiv] piCongr {ι₁ ι₂ : Type*} {β₁ : ι₁ → Type*} {β₂ : ι₂ → Type*} [∀ i₁, UniformSpace (β₁ i₁)] [∀ i₂, UniformSpace (β₂ i₂)] (e : ι₁ ≃ ι₂) (F : ∀ i₁, β₁ i₁ ≃ᵤ β₂ (e i₁)) : (∀ i₁, β₁ i₁) ≃ᵤ ∀ i₂, β₂ i₂ := (UniformEquiv.piCongrRight F).trans (UniformEquiv.piCongrLeft e)
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piCongr
`Equiv.piCongr` as a uniform isomorphism: this is the natural isomorphism `Π i₁, β₁ i ≃ᵤ Π i₂, β₂ i₂` obtained from a bijection `ι₁ ≃ ι₂` and isomorphisms `β₁ i₁ ≃ᵤ β₂ (e i₁)` for each `i₁ : ι₁`.
ulift : ULift.{v, u} α ≃ᵤ α := { Equiv.ulift with uniformContinuous_toFun := uniformContinuous_comap uniformContinuous_invFun := by have hf : IsUniformInducing (@Equiv.ulift.{v, u} α).toFun := ⟨rfl⟩ simp_rw [hf.uniformContinuous_iff] exact uniformContinuous_id }
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
ulift
Uniform equivalence between `ULift α` and `α`.
@[simps! -fullyApplied] funUnique (ι α : Type*) [Unique ι] [UniformSpace α] : (ι → α) ≃ᵤ α where toEquiv := Equiv.funUnique ι α uniformContinuous_toFun := Pi.uniformContinuous_proj _ _ uniformContinuous_invFun := uniformContinuous_pi.mpr fun _ => uniformContinuous_id
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
funUnique
If `ι` has a unique element, then `ι → α` is uniformly isomorphic to `α`.
@[simps! -fullyApplied] piFinTwo (α : Fin 2 → Type u) [∀ i, UniformSpace (α i)] : (∀ i, α i) ≃ᵤ α 0 × α 1 where toEquiv := piFinTwoEquiv α uniformContinuous_toFun := (Pi.uniformContinuous_proj _ 0).prodMk (Pi.uniformContinuous_proj _ 1) uniformContinuous_invFun := uniformContinuous_pi.mpr <| Fin.forall_fin_two.2 ⟨uniformContinuous_fst, uniformContinuous_snd⟩
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
piFinTwo
Uniform isomorphism between dependent functions `Π i : Fin 2, α i` and `α 0 × α 1`.
@[simps! -fullyApplied] finTwoArrow (α : Type*) [UniformSpace α] : (Fin 2 → α) ≃ᵤ α × α := { piFinTwo fun _ => α with toEquiv := finTwoArrowEquiv α }
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
finTwoArrow
Uniform isomorphism between `α² = Fin 2 → α` and `α × α`.
image (e : α ≃ᵤ β) (s : Set α) : s ≃ᵤ e '' s where uniformContinuous_toFun := (e.uniformContinuous.comp uniformContinuous_subtype_val).subtype_mk _ uniformContinuous_invFun := (e.symm.uniformContinuous.comp uniformContinuous_subtype_val).subtype_mk _ toEquiv := e.toEquiv.image s
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
image
A subset of a uniform space is uniformly isomorphic to its image under a uniform isomorphism.
Equiv.toUniformEquivOfIsUniformInducing [UniformSpace α] [UniformSpace β] (f : α ≃ β) (hf : IsUniformInducing f) : α ≃ᵤ β := { f with uniformContinuous_toFun := hf.uniformContinuous uniformContinuous_invFun := hf.uniformContinuous_iff.2 <| by simpa using uniformContinuous_id }
def
Topology
[ "Mathlib.Logic.Equiv.Fin.Basic", "Mathlib.Topology.UniformSpace.UniformEmbedding", "Mathlib.Topology.UniformSpace.Pi" ]
Mathlib/Topology/UniformSpace/Equiv.lean
Equiv.toUniformEquivOfIsUniformInducing
A uniform inducing equiv between uniform spaces is a uniform isomorphism.
CompactSpace.uniformContinuous_of_continuous [CompactSpace α] {f : α → β} (h : Continuous f) : UniformContinuous f := calc map (Prod.map f f) (𝓤 α) = map (Prod.map f f) (𝓝ˢ (diagonal α)) := by rw [nhdsSet_diagonal_eq_uniformity] _ ≤ 𝓝ˢ (diagonal β) := (h.prodMap h).tendsto_nhdsSet mapsTo_prodMap_diagonal _ ≤ 𝓤 β := nhdsSet_diagonal_le_uniformity
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
CompactSpace.uniformContinuous_of_continuous
Heine-Cantor: a continuous function on a compact uniform space is uniformly continuous.
IsCompact.uniformContinuousOn_of_continuous {s : Set α} {f : α → β} (hs : IsCompact s) (hf : ContinuousOn f s) : UniformContinuousOn f s := by rw [uniformContinuousOn_iff_restrict] rw [isCompact_iff_compactSpace] at hs rw [continuousOn_iff_continuous_restrict] at hf exact CompactSpace.uniformContinuous_of_continuous hf
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
IsCompact.uniformContinuousOn_of_continuous
Heine-Cantor: a continuous function on a compact set of a uniform space is uniformly continuous.
IsCompact.uniformContinuousAt_of_continuousAt {r : Set (β × β)} {s : Set α} (hs : IsCompact s) (f : α → β) (hf : ∀ a ∈ s, ContinuousAt f a) (hr : r ∈ 𝓤 β) : { x : α × α | x.1 ∈ s → (f x.1, f x.2) ∈ r } ∈ 𝓤 α := by obtain ⟨t, ht, htsymm, htr⟩ := comp_symm_mem_uniformity_sets hr choose U hU T hT hb using fun a ha => exists_mem_nhds_ball_subset_of_mem_nhds ((hf a ha).preimage_mem_nhds <| mem_nhds_left _ ht) obtain ⟨fs, hsU⟩ := hs.elim_nhds_subcover' U hU apply mem_of_superset ((biInter_finset_mem fs).2 fun a _ => hT a a.2) rintro ⟨a₁, a₂⟩ h h₁ obtain ⟨a, ha, haU⟩ := Set.mem_iUnion₂.1 (hsU h₁) apply htr refine ⟨f a, htsymm.mk_mem_comm.1 (hb _ _ _ haU ?_), hb _ _ _ haU ?_⟩ exacts [mem_ball_self _ (hT a a.2), mem_iInter₂.1 h a ha]
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
IsCompact.uniformContinuousAt_of_continuousAt
If `s` is compact and `f` is continuous at all points of `s`, then `f` is "uniformly continuous at the set `s`", i.e. `f x` is close to `f y` whenever `x ∈ s` and `y` is close to `x` (even if `y` is not itself in `s`, so this is a stronger assertion than `UniformContinuousOn s`).
Continuous.uniformContinuous_of_tendsto_cocompact {f : α → β} {x : β} (h_cont : Continuous f) (hx : Tendsto f (cocompact α) (𝓝 x)) : UniformContinuous f := uniformContinuous_def.2 fun r hr => by obtain ⟨t, ht, htsymm, htr⟩ := comp_symm_mem_uniformity_sets hr obtain ⟨s, hs, hst⟩ := mem_cocompact.1 (hx <| mem_nhds_left _ ht) apply mem_of_superset (symmetrize_mem_uniformity <| (hs.uniformContinuousAt_of_continuousAt f fun _ _ => h_cont.continuousAt) <| symmetrize_mem_uniformity hr) rintro ⟨b₁, b₂⟩ h by_cases h₁ : b₁ ∈ s; · exact (h.1 h₁).1 by_cases h₂ : b₂ ∈ s; · exact (h.2 h₂).2 apply htr exact ⟨x, htsymm.mk_mem_comm.1 (hst h₁), hst h₂⟩ @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
Continuous.uniformContinuous_of_tendsto_cocompact
null
HasCompactMulSupport.uniformContinuous_of_continuous {f : α → β} [One β] (h1 : HasCompactMulSupport f) (h2 : Continuous f) : UniformContinuous f := h2.uniformContinuous_of_tendsto_cocompact h1.is_one_at_infty
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
HasCompactMulSupport.uniformContinuous_of_continuous
null
ContinuousOn.tendstoUniformly [LocallyCompactSpace α] [CompactSpace β] [UniformSpace γ] {f : α → β → γ} {x : α} {U : Set α} (hxU : U ∈ 𝓝 x) (h : ContinuousOn ↿f (U ×ˢ univ)) : TendstoUniformly f (f x) (𝓝 x) := by rcases LocallyCompactSpace.local_compact_nhds _ _ hxU with ⟨K, hxK, hKU, hK⟩ have : UniformContinuousOn ↿f (K ×ˢ univ) := IsCompact.uniformContinuousOn_of_continuous (hK.prod isCompact_univ) (h.mono <| prod_mono hKU Subset.rfl) exact this.tendstoUniformly hxK
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
ContinuousOn.tendstoUniformly
A family of functions `α → β → γ` tends uniformly to its value at `x` if `α` is locally compact, `β` is compact and `f` is continuous on `U × (univ : Set β)` for some neighborhood `U` of `x`.
Continuous.tendstoUniformly [WeaklyLocallyCompactSpace α] [CompactSpace β] [UniformSpace γ] (f : α → β → γ) (h : Continuous ↿f) (x : α) : TendstoUniformly f (f x) (𝓝 x) := let ⟨K, hK, hxK⟩ := exists_compact_mem_nhds x have : UniformContinuousOn ↿f (K ×ˢ univ) := IsCompact.uniformContinuousOn_of_continuous (hK.prod isCompact_univ) h.continuousOn this.tendstoUniformly hxK
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
Continuous.tendstoUniformly
A continuous family of functions `α → β → γ` tends uniformly to its value at `x` if `α` is weakly locally compact and `β` is compact.
IsCompact.mem_uniformity_of_prod {α β E : Type*} [TopologicalSpace α] [TopologicalSpace β] [UniformSpace E] {f : α → β → E} {s : Set α} {k : Set β} {q : α} {u : Set (E × E)} (hk : IsCompact k) (hf : ContinuousOn f.uncurry (s ×ˢ k)) (hq : q ∈ s) (hu : u ∈ 𝓤 E) : ∃ v ∈ 𝓝[s] q, ∀ p ∈ v, ∀ x ∈ k, (f p x, f q x) ∈ u := by apply hk.induction_on (p := fun t ↦ ∃ v ∈ 𝓝[s] q, ∀ p ∈ v, ∀ x ∈ t, (f p x, f q x) ∈ u) · exact ⟨univ, univ_mem, by simp⟩ · intro t' t ht't ⟨v, v_mem, hv⟩ exact ⟨v, v_mem, fun p hp x hx ↦ hv p hp x (ht't hx)⟩ · intro t t' ⟨v, v_mem, hv⟩ ⟨v', v'_mem, hv'⟩ refine ⟨v ∩ v', inter_mem v_mem v'_mem, fun p hp x hx ↦ ?_⟩ rcases hx with h'x|h'x · exact hv p hp.1 x h'x · exact hv' p hp.2 x h'x · rcases comp_symm_of_uniformity hu with ⟨u', u'_mem, u'_symm, hu'⟩ intro x hx obtain ⟨v, hv, w, hw, hvw⟩ : ∃ v ∈ 𝓝[s] q, ∃ w ∈ 𝓝[k] x, v ×ˢ w ⊆ f.uncurry ⁻¹' {z | (f q x, z) ∈ u'} := mem_nhdsWithin_prod_iff.1 (hf (q, x) ⟨hq, hx⟩ (mem_nhds_left (f q x) u'_mem)) refine ⟨w, hw, v, hv, fun p hp y hy ↦ ?_⟩ have A : (f q x, f p y) ∈ u' := hvw (⟨hp, hy⟩ : (p, y) ∈ v ×ˢ w) have B : (f q x, f q y) ∈ u' := hvw (⟨mem_of_mem_nhdsWithin hq hv, hy⟩ : (q, y) ∈ v ×ˢ w) exact hu' (prodMk_mem_compRel (u'_symm A) B)
lemma
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
IsCompact.mem_uniformity_of_prod
In a product space `α × β`, assume that a function `f` is continuous on `s × k` where `k` is compact. Then, along the fiber above any `q ∈ s`, `f` is transversely uniformly continuous, i.e., if `p ∈ s` is close enough to `q`, then `f p x` is uniformly close to `f q x` for all `x ∈ k`.
CompactSpace.uniformEquicontinuous_of_equicontinuous {ι : Type*} {F : ι → β → α} [CompactSpace β] (h : Equicontinuous F) : UniformEquicontinuous F := by rw [equicontinuous_iff_continuous] at h rw [uniformEquicontinuous_iff_uniformContinuous] exact CompactSpace.uniformContinuous_of_continuous h
theorem
Topology
[ "Mathlib.Topology.Algebra.Support", "Mathlib.Topology.UniformSpace.Compact", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/UniformSpace/HeineCantor.lean
CompactSpace.uniformEquicontinuous_of_equicontinuous
An equicontinuous family of functions defined on a compact uniform space is automatically uniformly equicontinuous.
more commonly encountered in the literature. The reason is that in our definition the neighborhood `v` of `x` can depend on the entourage `u`; so our condition is *a priori* weaker than the usual one, although the two conditions are equivalent if the domain is locally compact. See `tendstoLocallyUniformlyOn_of_forall_exists_nhds` for the one-way implication; the equivalence assuming local compactness is part of `tendstoLocallyUniformlyOn_TFAE`. We adopt this weaker condition because it is more general but appears to be sufficient for the standard applications of locally-uniform convergence (in particular, for proving that a locally-uniform limit of continuous functions is continuous). We also define variants for locally uniform convergence on a subset, called `TendstoLocallyUniformlyOn F f p s`.
def
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
more
null
TendstoLocallyUniformlyOn (F : ι → α → β) (f : α → β) (p : Filter ι) (s : Set α) := ∀ u ∈ 𝓤 β, ∀ x ∈ s, ∃ t ∈ 𝓝[s] x, ∀ᶠ n in p, ∀ y ∈ t, (f y, F n y) ∈ u
def
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
TendstoLocallyUniformlyOn
A sequence of functions `Fₙ` converges locally uniformly on a set `s` to a limiting function `f` with respect to a filter `p` if, for any entourage of the diagonal `u`, for any `x ∈ s`, one has `p`-eventually `(f y, Fₙ y) ∈ u` for all `y` in a neighborhood of `x` in `s`.
TendstoLocallyUniformly (F : ι → α → β) (f : α → β) (p : Filter ι) := ∀ u ∈ 𝓤 β, ∀ x : α, ∃ t ∈ 𝓝 x, ∀ᶠ n in p, ∀ y ∈ t, (f y, F n y) ∈ u
def
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
TendstoLocallyUniformly
A sequence of functions `Fₙ` converges locally uniformly to a limiting function `f` with respect to a filter `p` if, for any entourage of the diagonal `u`, for any `x`, one has `p`-eventually `(f y, Fₙ y) ∈ u` for all `y` in a neighborhood of `x`.
tendstoLocallyUniformlyOn_univ : TendstoLocallyUniformlyOn F f p univ ↔ TendstoLocallyUniformly F f p := by simp [TendstoLocallyUniformlyOn, TendstoLocallyUniformly, nhdsWithin_univ]
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformlyOn_univ
null
tendstoLocallyUniformlyOn_iff_forall_tendsto : TendstoLocallyUniformlyOn F f p s ↔ ∀ x ∈ s, Tendsto (fun y : ι × α => (f y.2, F y.1 y.2)) (p ×ˢ 𝓝[s] x) (𝓤 β) := forall₂_swap.trans <| forall₄_congr fun _ _ _ _ => by simp_rw [mem_map, mem_prod_iff_right, mem_preimage] nonrec theorem IsOpen.tendstoLocallyUniformlyOn_iff_forall_tendsto (hs : IsOpen s) : TendstoLocallyUniformlyOn F f p s ↔ ∀ x ∈ s, Tendsto (fun y : ι × α => (f y.2, F y.1 y.2)) (p ×ˢ 𝓝 x) (𝓤 β) := tendstoLocallyUniformlyOn_iff_forall_tendsto.trans <| forall₂_congr fun x hx => by rw [hs.nhdsWithin_eq hx]
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformlyOn_iff_forall_tendsto
null
tendstoLocallyUniformly_iff_forall_tendsto : TendstoLocallyUniformly F f p ↔ ∀ x, Tendsto (fun y : ι × α => (f y.2, F y.1 y.2)) (p ×ˢ 𝓝 x) (𝓤 β) := by simp [← tendstoLocallyUniformlyOn_univ, isOpen_univ.tendstoLocallyUniformlyOn_iff_forall_tendsto]
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformly_iff_forall_tendsto
null
tendstoLocallyUniformlyOn_iff_tendstoLocallyUniformly_comp_coe : TendstoLocallyUniformlyOn F f p s ↔ TendstoLocallyUniformly (fun i (x : s) => F i x) (f ∘ (↑)) p := by simp only [tendstoLocallyUniformly_iff_forall_tendsto, Subtype.forall', tendsto_map'_iff, tendstoLocallyUniformlyOn_iff_forall_tendsto, ← map_nhds_subtype_val, prod_map_right]; rfl
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformlyOn_iff_tendstoLocallyUniformly_comp_coe
null
protected TendstoUniformlyOn.tendstoLocallyUniformlyOn (h : TendstoUniformlyOn F f p s) : TendstoLocallyUniformlyOn F f p s := fun u hu _ _ => ⟨s, self_mem_nhdsWithin, by simpa using h u hu⟩
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
TendstoUniformlyOn.tendstoLocallyUniformlyOn
null
protected TendstoUniformly.tendstoLocallyUniformly (h : TendstoUniformly F f p) : TendstoLocallyUniformly F f p := fun u hu _ => ⟨univ, univ_mem, by simpa using h u hu⟩
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
TendstoUniformly.tendstoLocallyUniformly
null
TendstoLocallyUniformlyOn.mono (h : TendstoLocallyUniformlyOn F f p s) (h' : s' ⊆ s) : TendstoLocallyUniformlyOn F f p s' := by intro u hu x hx rcases h u hu x (h' hx) with ⟨t, ht, H⟩ exact ⟨t, nhdsWithin_mono x h' ht, H.mono fun n => id⟩
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
TendstoLocallyUniformlyOn.mono
null
tendstoLocallyUniformlyOn_iUnion {ι' : Sort*} {S : ι' → Set α} (hS : ∀ i, IsOpen (S i)) (h : ∀ i, TendstoLocallyUniformlyOn F f p (S i)) : TendstoLocallyUniformlyOn F f p (⋃ i, S i) := (isOpen_iUnion hS).tendstoLocallyUniformlyOn_iff_forall_tendsto.2 fun _x hx => let ⟨i, hi⟩ := mem_iUnion.1 hx (hS i).tendstoLocallyUniformlyOn_iff_forall_tendsto.1 (h i) _ hi
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformlyOn_iUnion
null
tendstoLocallyUniformlyOn_biUnion {s : Set γ} {S : γ → Set α} (hS : ∀ i ∈ s, IsOpen (S i)) (h : ∀ i ∈ s, TendstoLocallyUniformlyOn F f p (S i)) : TendstoLocallyUniformlyOn F f p (⋃ i ∈ s, S i) := tendstoLocallyUniformlyOn_iUnion (fun i => isOpen_iUnion (hS i)) fun i ↦ tendstoLocallyUniformlyOn_iUnion (hS i) (h i)
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformlyOn_biUnion
null
tendstoLocallyUniformlyOn_sUnion (S : Set (Set α)) (hS : ∀ s ∈ S, IsOpen s) (h : ∀ s ∈ S, TendstoLocallyUniformlyOn F f p s) : TendstoLocallyUniformlyOn F f p (⋃₀ S) := by rw [sUnion_eq_biUnion] exact tendstoLocallyUniformlyOn_biUnion hS h
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformlyOn_sUnion
null
TendstoLocallyUniformlyOn.union (hs₁ : IsOpen s) (hs₂ : IsOpen s') (h₁ : TendstoLocallyUniformlyOn F f p s) (h₂ : TendstoLocallyUniformlyOn F f p s') : TendstoLocallyUniformlyOn F f p (s ∪ s') := by rw [← sUnion_pair] refine tendstoLocallyUniformlyOn_sUnion _ ?_ ?_ <;> simp [*]
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
TendstoLocallyUniformlyOn.union
null
protected TendstoLocallyUniformly.tendstoLocallyUniformlyOn (h : TendstoLocallyUniformly F f p) : TendstoLocallyUniformlyOn F f p s := (tendstoLocallyUniformlyOn_univ.mpr h).mono (subset_univ _)
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
TendstoLocallyUniformly.tendstoLocallyUniformlyOn
null
tendstoLocallyUniformly_iff_tendstoUniformly_of_compactSpace [CompactSpace α] : TendstoLocallyUniformly F f p ↔ TendstoUniformly F f p := by refine ⟨fun h V hV => ?_, TendstoUniformly.tendstoLocallyUniformly⟩ choose U hU using h V hV obtain ⟨t, ht⟩ := isCompact_univ.elim_nhds_subcover' (fun k _ => U k) fun k _ => (hU k).1 replace hU := fun x : t => (hU x).2 rw [← eventually_all] at hU refine hU.mono fun i hi x => ?_ specialize ht (mem_univ x) simp only [exists_prop, mem_iUnion, SetCoe.exists, exists_and_right] at ht obtain ⟨y, ⟨hy₁, hy₂⟩, hy₃⟩ := ht exact hi ⟨⟨y, hy₁⟩, hy₂⟩ x hy₃
theorem
Topology
[ "Mathlib.Topology.UniformSpace.UniformConvergence" ]
Mathlib/Topology/UniformSpace/LocallyUniformConvergence.lean
tendstoLocallyUniformly_iff_tendstoUniformly_of_compactSpace
On a compact space, locally uniform convergence is just uniform convergence.