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toTopologicalSpace_inf {u v : UniformSpace α} : (u ⊓ v).toTopologicalSpace = u.toTopologicalSpace ⊓ v.toTopologicalSpace := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
toTopologicalSpace_inf
null
UniformContinuous.continuous [UniformSpace α] [UniformSpace β] {f : α → β} (hf : UniformContinuous f) : Continuous f := continuous_iff_le_induced.mpr <| UniformSpace.toTopologicalSpace_mono <| uniformContinuous_iff.1 hf
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.continuous
null
ULift.uniformSpace [UniformSpace α] : UniformSpace (ULift α) := UniformSpace.comap ULift.down ‹_›
instance
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
ULift.uniformSpace
Uniform space structure on `ULift α`.
OrderDual.instUniformSpace [UniformSpace α] : UniformSpace (αᵒᵈ) := ‹UniformSpace α›
instance
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
OrderDual.instUniformSpace
Uniform space structure on `αᵒᵈ`.
UniformContinuous.inf_rng {f : α → β} {u₁ : UniformSpace α} {u₂ u₃ : UniformSpace β} (h₁ : UniformContinuous[u₁, u₂] f) (h₂ : UniformContinuous[u₁, u₃] f) : UniformContinuous[u₁, u₂ ⊓ u₃] f := tendsto_inf.mpr ⟨h₁, h₂⟩
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.inf_rng
null
UniformContinuous.inf_dom_left {f : α → β} {u₁ u₂ : UniformSpace α} {u₃ : UniformSpace β} (hf : UniformContinuous[u₁, u₃] f) : UniformContinuous[u₁ ⊓ u₂, u₃] f := tendsto_inf_left hf
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.inf_dom_left
null
UniformContinuous.inf_dom_right {f : α → β} {u₁ u₂ : UniformSpace α} {u₃ : UniformSpace β} (hf : UniformContinuous[u₂, u₃] f) : UniformContinuous[u₁ ⊓ u₂, u₃] f := tendsto_inf_right hf
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.inf_dom_right
null
uniformContinuous_sInf_dom {f : α → β} {u₁ : Set (UniformSpace α)} {u₂ : UniformSpace β} {u : UniformSpace α} (h₁ : u ∈ u₁) (hf : UniformContinuous[u, u₂] f) : UniformContinuous[sInf u₁, u₂] f := by delta UniformContinuous rw [sInf_eq_iInf', iInf_uniformity] exact tendsto_iInf' ⟨u, h₁⟩ hf
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_sInf_dom
null
uniformContinuous_sInf_rng {f : α → β} {u₁ : UniformSpace α} {u₂ : Set (UniformSpace β)} : UniformContinuous[u₁, sInf u₂] f ↔ ∀ u ∈ u₂, UniformContinuous[u₁, u] f := by delta UniformContinuous rw [sInf_eq_iInf', iInf_uniformity, tendsto_iInf, SetCoe.forall]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_sInf_rng
null
uniformContinuous_iInf_dom {f : α → β} {u₁ : ι → UniformSpace α} {u₂ : UniformSpace β} {i : ι} (hf : UniformContinuous[u₁ i, u₂] f) : UniformContinuous[iInf u₁, u₂] f := by delta UniformContinuous rw [iInf_uniformity] exact tendsto_iInf' i hf
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_iInf_dom
null
uniformContinuous_iInf_rng {f : α → β} {u₁ : UniformSpace α} {u₂ : ι → UniformSpace β} : UniformContinuous[u₁, iInf u₂] f ↔ ∀ i, UniformContinuous[u₁, u₂ i] f := by delta UniformContinuous rw [iInf_uniformity, tendsto_iInf]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_iInf_rng
null
discreteTopology_of_discrete_uniformity [hα : UniformSpace α] (h : uniformity α = 𝓟 idRel) : DiscreteTopology α := ⟨(UniformSpace.ext h.symm : ⊥ = hα) ▸ rfl⟩
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
discreteTopology_of_discrete_uniformity
A uniform space with the discrete uniformity has the discrete topology.
uniformContinuous_ofMul : UniformContinuous (ofMul : α → Additive α) := uniformContinuous_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_ofMul
null
uniformContinuous_toMul : UniformContinuous (toMul : Additive α → α) := uniformContinuous_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_toMul
null
uniformContinuous_ofAdd : UniformContinuous (ofAdd : α → Multiplicative α) := uniformContinuous_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_ofAdd
null
uniformContinuous_toAdd : UniformContinuous (toAdd : Multiplicative α → α) := uniformContinuous_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_toAdd
null
uniformity_additive : 𝓤 (Additive α) = (𝓤 α).map (Prod.map ofMul ofMul) := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_additive
null
uniformity_multiplicative : 𝓤 (Multiplicative α) = (𝓤 α).map (Prod.map ofAdd ofAdd) := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_multiplicative
null
instUniformSpaceSubtype {p : α → Prop} [t : UniformSpace α] : UniformSpace (Subtype p) := UniformSpace.comap Subtype.val t
instance
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
instUniformSpaceSubtype
null
uniformity_subtype {p : α → Prop} [UniformSpace α] : 𝓤 (Subtype p) = comap (fun q : Subtype p × Subtype p => (q.1.1, q.2.1)) (𝓤 α) := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_subtype
null
uniformity_setCoe {s : Set α} [UniformSpace α] : 𝓤 s = comap (Prod.map ((↑) : s → α) ((↑) : s → α)) (𝓤 α) := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_setCoe
null
map_uniformity_set_coe {s : Set α} [UniformSpace α] : map (Prod.map (↑) (↑)) (𝓤 s) = 𝓤 α ⊓ 𝓟 (s ×ˢ s) := by rw [uniformity_setCoe, map_comap, range_prodMap, Subtype.range_val]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
map_uniformity_set_coe
null
uniformContinuous_subtype_val {p : α → Prop} [UniformSpace α] : UniformContinuous (Subtype.val : { a : α // p a } → α) := uniformContinuous_comap
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_subtype_val
null
UniformContinuous.subtype_mk {p : α → Prop} [UniformSpace α] [UniformSpace β] {f : β → α} (hf : UniformContinuous f) (h : ∀ x, p (f x)) : UniformContinuous (fun x => ⟨f x, h x⟩ : β → Subtype p) := uniformContinuous_comap' hf
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.subtype_mk
null
uniformContinuousOn_iff_restrict [UniformSpace α] [UniformSpace β] {f : α → β} {s : Set α} : UniformContinuousOn f s ↔ UniformContinuous (s.restrict f) := by delta UniformContinuousOn UniformContinuous rw [← map_uniformity_set_coe, tendsto_map'_iff]; rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuousOn_iff_restrict
null
tendsto_of_uniformContinuous_subtype [UniformSpace α] [UniformSpace β] {f : α → β} {s : Set α} {a : α} (hf : UniformContinuous fun x : s => f x.val) (ha : s ∈ 𝓝 a) : Tendsto f (𝓝 a) (𝓝 (f a)) := by rw [(@map_nhds_subtype_coe_eq_nhds α _ s a (mem_of_mem_nhds ha) ha).symm] exact tendsto_map' hf.continuous.continuousAt
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
tendsto_of_uniformContinuous_subtype
null
UniformContinuousOn.continuousOn [UniformSpace α] [UniformSpace β] {f : α → β} {s : Set α} (h : UniformContinuousOn f s) : ContinuousOn f s := by rw [uniformContinuousOn_iff_restrict] at h rw [continuousOn_iff_continuous_restrict] exact h.continuous @[to_additive]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuousOn.continuousOn
null
@[to_additive] uniformity_mulOpposite [UniformSpace α] : 𝓤 αᵐᵒᵖ = comap (fun q : αᵐᵒᵖ × αᵐᵒᵖ => (q.1.unop, q.2.unop)) (𝓤 α) := rfl @[to_additive (attr := simp)]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_mulOpposite
null
comap_uniformity_mulOpposite [UniformSpace α] : comap (fun p : α × α => (MulOpposite.op p.1, MulOpposite.op p.2)) (𝓤 αᵐᵒᵖ) = 𝓤 α := by simpa [uniformity_mulOpposite, comap_comap, (· ∘ ·)] using comap_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
comap_uniformity_mulOpposite
null
@[to_additive] uniformContinuous_unop [UniformSpace α] : UniformContinuous (unop : αᵐᵒᵖ → α) := uniformContinuous_comap @[to_additive]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_unop
null
uniformContinuous_op [UniformSpace α] : UniformContinuous (op : α → αᵐᵒᵖ) := uniformContinuous_comap' uniformContinuous_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_op
null
instUniformSpaceProd [u₁ : UniformSpace α] [u₂ : UniformSpace β] : UniformSpace (α × β) := u₁.comap Prod.fst ⊓ u₂.comap Prod.snd
instance
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
instUniformSpaceProd
null
uniformity_prod [UniformSpace α] [UniformSpace β] : 𝓤 (α × β) = ((𝓤 α).comap fun p : (α × β) × α × β => (p.1.1, p.2.1)) ⊓ (𝓤 β).comap fun p : (α × β) × α × β => (p.1.2, p.2.2) := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_prod
null
uniformity_prod_eq_comap_prod [UniformSpace α] [UniformSpace β] : 𝓤 (α × β) = comap (fun p : (α × β) × α × β => ((p.1.1, p.2.1), (p.1.2, p.2.2))) (𝓤 α ×ˢ 𝓤 β) := by simp_rw [uniformity_prod, prod_eq_inf, Filter.comap_inf, Filter.comap_comap, Function.comp_def]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_prod_eq_comap_prod
null
uniformity_prod_eq_prod [UniformSpace α] [UniformSpace β] : 𝓤 (α × β) = map (fun p : (α × α) × β × β => ((p.1.1, p.2.1), (p.1.2, p.2.2))) (𝓤 α ×ˢ 𝓤 β) := by rw [map_swap4_eq_comap, uniformity_prod_eq_comap_prod]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformity_prod_eq_prod
null
mem_uniformity_of_uniformContinuous_invariant [UniformSpace α] [UniformSpace β] {s : Set (β × β)} {f : α → α → β} (hf : UniformContinuous fun p : α × α => f p.1 p.2) (hs : s ∈ 𝓤 β) : ∃ u ∈ 𝓤 α, ∀ a b c, (a, b) ∈ u → (f a c, f b c) ∈ s := by rw [UniformContinuous, uniformity_prod_eq_prod, tendsto_map'_iff] at hf rcases mem_prod_iff.1 (mem_map.1 <| hf hs) with ⟨u, hu, v, hv, huvt⟩ exact ⟨u, hu, fun a b c hab => @huvt ((_, _), (_, _)) ⟨hab, refl_mem_uniformity hv⟩⟩
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
mem_uniformity_of_uniformContinuous_invariant
null
entourageProd (u : Set (α × α)) (v : Set (β × β)) : Set ((α × β) × α × β) := {((a₁, b₁),(a₂, b₂)) | (a₁, a₂) ∈ u ∧ (b₁, b₂) ∈ v}
def
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
entourageProd
An entourage of the diagonal in `α` and an entourage in `β` yield an entourage in `α × β` once we permute coordinates.
mem_entourageProd {u : Set (α × α)} {v : Set (β × β)} {p : (α × β) × α × β} : p ∈ entourageProd u v ↔ (p.1.1, p.2.1) ∈ u ∧ (p.1.2, p.2.2) ∈ v := Iff.rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
mem_entourageProd
null
entourageProd_mem_uniformity [t₁ : UniformSpace α] [t₂ : UniformSpace β] {u : Set (α × α)} {v : Set (β × β)} (hu : u ∈ 𝓤 α) (hv : v ∈ 𝓤 β) : entourageProd u v ∈ 𝓤 (α × β) := by rw [uniformity_prod]; exact inter_mem_inf (preimage_mem_comap hu) (preimage_mem_comap hv)
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
entourageProd_mem_uniformity
null
ball_entourageProd (u : Set (α × α)) (v : Set (β × β)) (x : α × β) : ball x (entourageProd u v) = ball x.1 u ×ˢ ball x.2 v := by ext p; simp only [ball, entourageProd, Set.mem_setOf_eq, Set.mem_prod, Set.mem_preimage]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
ball_entourageProd
null
IsSymmetricRel.entourageProd {u : Set (α × α)} {v : Set (β × β)} (hu : IsSymmetricRel u) (hv : IsSymmetricRel v) : IsSymmetricRel (entourageProd u v) := Set.ext fun _ ↦ and_congr hu.mk_mem_comm hv.mk_mem_comm
lemma
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
IsSymmetricRel.entourageProd
null
Filter.HasBasis.uniformity_prod {ιa ιb : Type*} [UniformSpace α] [UniformSpace β] {pa : ιa → Prop} {pb : ιb → Prop} {sa : ιa → Set (α × α)} {sb : ιb → Set (β × β)} (ha : (𝓤 α).HasBasis pa sa) (hb : (𝓤 β).HasBasis pb sb) : (𝓤 (α × β)).HasBasis (fun i : ιa × ιb ↦ pa i.1 ∧ pb i.2) (fun i ↦ entourageProd (sa i.1) (sb i.2)) := (ha.comap _).inf (hb.comap _)
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
Filter.HasBasis.uniformity_prod
null
entourageProd_subset [UniformSpace α] [UniformSpace β] {s : Set ((α × β) × α × β)} (h : s ∈ 𝓤 (α × β)) : ∃ u ∈ 𝓤 α, ∃ v ∈ 𝓤 β, entourageProd u v ⊆ s := by rcases (((𝓤 α).basis_sets.uniformity_prod (𝓤 β).basis_sets).mem_iff' s).1 h with ⟨w, hw⟩ use w.1, hw.1.1, w.2, hw.1.2, hw.2
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
entourageProd_subset
null
tendsto_prod_uniformity_fst [UniformSpace α] [UniformSpace β] : Tendsto (fun p : (α × β) × α × β => (p.1.1, p.2.1)) (𝓤 (α × β)) (𝓤 α) := le_trans (map_mono inf_le_left) map_comap_le
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
tendsto_prod_uniformity_fst
null
tendsto_prod_uniformity_snd [UniformSpace α] [UniformSpace β] : Tendsto (fun p : (α × β) × α × β => (p.1.2, p.2.2)) (𝓤 (α × β)) (𝓤 β) := le_trans (map_mono inf_le_right) map_comap_le
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
tendsto_prod_uniformity_snd
null
uniformContinuous_fst [UniformSpace α] [UniformSpace β] : UniformContinuous fun p : α × β => p.1 := tendsto_prod_uniformity_fst
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_fst
null
uniformContinuous_snd [UniformSpace α] [UniformSpace β] : UniformContinuous fun p : α × β => p.2 := tendsto_prod_uniformity_snd variable [UniformSpace α] [UniformSpace β] [UniformSpace γ]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_snd
null
UniformContinuous.prodMk {f₁ : α → β} {f₂ : α → γ} (h₁ : UniformContinuous f₁) (h₂ : UniformContinuous f₂) : UniformContinuous fun a => (f₁ a, f₂ a) := by rw [UniformContinuous, uniformity_prod] exact tendsto_inf.2 ⟨tendsto_comap_iff.2 h₁, tendsto_comap_iff.2 h₂⟩ @[deprecated (since := "2025-03-10")] alias UniformContinuous.prod_mk := UniformContinuous.prodMk
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.prodMk
null
UniformContinuous.prodMk_left {f : α × β → γ} (h : UniformContinuous f) (b) : UniformContinuous fun a => f (a, b) := h.comp (uniformContinuous_id.prodMk uniformContinuous_const) @[deprecated (since := "2025-03-10")] alias UniformContinuous.prod_mk_left := UniformContinuous.prodMk_left
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.prodMk_left
null
UniformContinuous.prodMk_right {f : α × β → γ} (h : UniformContinuous f) (a) : UniformContinuous fun b => f (a, b) := h.comp (uniformContinuous_const.prodMk uniformContinuous_id) @[deprecated (since := "2025-03-10")] alias UniformContinuous.prod_mk_right := UniformContinuous.prodMk_right
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.prodMk_right
null
UniformContinuous.prodMap [UniformSpace δ] {f : α → γ} {g : β → δ} (hf : UniformContinuous f) (hg : UniformContinuous g) : UniformContinuous (Prod.map f g) := (hf.comp uniformContinuous_fst).prodMk (hg.comp uniformContinuous_snd)
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous.prodMap
null
toTopologicalSpace_prod {α} {β} [u : UniformSpace α] [v : UniformSpace β] : @UniformSpace.toTopologicalSpace (α × β) instUniformSpaceProd = @instTopologicalSpaceProd α β u.toTopologicalSpace v.toTopologicalSpace := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
toTopologicalSpace_prod
null
uniformContinuous_inf_dom_left₂ {α β γ} {f : α → β → γ} {ua1 ua2 : UniformSpace α} {ub1 ub2 : UniformSpace β} {uc1 : UniformSpace γ} (h : by haveI := ua1; haveI := ub1; exact UniformContinuous fun p : α × β => f p.1 p.2) : by haveI := ua1 ⊓ ua2; haveI := ub1 ⊓ ub2 exact UniformContinuous fun p : α × β => f p.1 p.2 := by have ha := @UniformContinuous.inf_dom_left _ _ id ua1 ua2 ua1 (@uniformContinuous_id _ (id _)) have hb := @UniformContinuous.inf_dom_left _ _ id ub1 ub2 ub1 (@uniformContinuous_id _ (id _)) have h_unif_cont_id := @UniformContinuous.prodMap _ _ _ _ (ua1 ⊓ ua2) (ub1 ⊓ ub2) ua1 ub1 _ _ ha hb exact @UniformContinuous.comp _ _ _ (id _) (id _) _ _ _ h h_unif_cont_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_inf_dom_left₂
A version of `UniformContinuous.inf_dom_left` for binary functions
uniformContinuous_inf_dom_right₂ {α β γ} {f : α → β → γ} {ua1 ua2 : UniformSpace α} {ub1 ub2 : UniformSpace β} {uc1 : UniformSpace γ} (h : by haveI := ua2; haveI := ub2; exact UniformContinuous fun p : α × β => f p.1 p.2) : by haveI := ua1 ⊓ ua2; haveI := ub1 ⊓ ub2 exact UniformContinuous fun p : α × β => f p.1 p.2 := by have ha := @UniformContinuous.inf_dom_right _ _ id ua1 ua2 ua2 (@uniformContinuous_id _ (id _)) have hb := @UniformContinuous.inf_dom_right _ _ id ub1 ub2 ub2 (@uniformContinuous_id _ (id _)) have h_unif_cont_id := @UniformContinuous.prodMap _ _ _ _ (ua1 ⊓ ua2) (ub1 ⊓ ub2) ua2 ub2 _ _ ha hb exact @UniformContinuous.comp _ _ _ (id _) (id _) _ _ _ h h_unif_cont_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_inf_dom_right₂
A version of `UniformContinuous.inf_dom_right` for binary functions
uniformContinuous_sInf_dom₂ {α β γ} {f : α → β → γ} {uas : Set (UniformSpace α)} {ubs : Set (UniformSpace β)} {ua : UniformSpace α} {ub : UniformSpace β} {uc : UniformSpace γ} (ha : ua ∈ uas) (hb : ub ∈ ubs) (hf : UniformContinuous fun p : α × β => f p.1 p.2) : by haveI := sInf uas; haveI := sInf ubs exact @UniformContinuous _ _ _ uc fun p : α × β => f p.1 p.2 := by let _ : UniformSpace (α × β) := instUniformSpaceProd have ha := uniformContinuous_sInf_dom ha uniformContinuous_id have hb := uniformContinuous_sInf_dom hb uniformContinuous_id have h_unif_cont_id := @UniformContinuous.prodMap _ _ _ _ (sInf uas) (sInf ubs) ua ub _ _ ha hb exact @UniformContinuous.comp _ _ _ (id _) (id _) _ _ _ hf h_unif_cont_id
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_sInf_dom₂
A version of `uniformContinuous_sInf_dom` for binary functions
UniformContinuous₂ (f : α → β → γ) := UniformContinuous (uncurry f)
def
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous₂
Uniform continuity for functions of two variables.
uniformContinuous₂_def (f : α → β → γ) : UniformContinuous₂ f ↔ UniformContinuous (uncurry f) := Iff.rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous₂_def
null
UniformContinuous₂.uniformContinuous {f : α → β → γ} (h : UniformContinuous₂ f) : UniformContinuous (uncurry f) := h
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous₂.uniformContinuous
null
uniformContinuous₂_curry (f : α × β → γ) : UniformContinuous₂ (Function.curry f) ↔ UniformContinuous f := by rw [UniformContinuous₂, uncurry_curry]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous₂_curry
null
UniformContinuous₂.comp {f : α → β → γ} {g : γ → δ} (hg : UniformContinuous g) (hf : UniformContinuous₂ f) : UniformContinuous₂ (g ∘₂ f) := hg.comp hf
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous₂.comp
null
UniformContinuous₂.bicompl {f : α → β → γ} {ga : δ → α} {gb : δ' → β} (hf : UniformContinuous₂ f) (hga : UniformContinuous ga) (hgb : UniformContinuous gb) : UniformContinuous₂ (bicompl f ga gb) := hf.uniformContinuous.comp (hga.prodMap hgb)
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
UniformContinuous₂.bicompl
null
toTopologicalSpace_subtype [u : UniformSpace α] {p : α → Prop} : @UniformSpace.toTopologicalSpace (Subtype p) instUniformSpaceSubtype = @instTopologicalSpaceSubtype α p u.toTopologicalSpace := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
toTopologicalSpace_subtype
null
Sum.instUniformSpace : UniformSpace (α ⊕ β) where uniformity := map (fun p : α × α => (inl p.1, inl p.2)) (𝓤 α) ⊔ map (fun p : β × β => (inr p.1, inr p.2)) (𝓤 β) symm := fun _ hs ↦ ⟨symm_le_uniformity hs.1, symm_le_uniformity hs.2⟩ comp := fun s hs ↦ by rcases comp_mem_uniformity_sets hs.1 with ⟨tα, htα, Htα⟩ rcases comp_mem_uniformity_sets hs.2 with ⟨tβ, htβ, Htβ⟩ filter_upwards [mem_lift' (union_mem_sup (image_mem_map htα) (image_mem_map htβ))] rintro ⟨_, _⟩ ⟨z, ⟨⟨a, b⟩, hab, ⟨⟩⟩ | ⟨⟨a, b⟩, hab, ⟨⟩⟩, ⟨⟨_, c⟩, hbc, ⟨⟩⟩ | ⟨⟨_, c⟩, hbc, ⟨⟩⟩⟩ exacts [@Htα (_, _) ⟨b, hab, hbc⟩, @Htβ (_, _) ⟨b, hab, hbc⟩] nhds_eq_comap_uniformity x := by ext cases x <;> simp [mem_comap', -mem_comap, nhds_inl, nhds_inr, nhds_eq_comap_uniformity, Prod.ext_iff]
instance
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
Sum.instUniformSpace
Uniformity on a disjoint union. Entourages of the diagonal in the union are obtained by taking independently an entourage of the diagonal in the first part, and an entourage of the diagonal in the second part.
union_mem_uniformity_sum {a : Set (α × α)} (ha : a ∈ 𝓤 α) {b : Set (β × β)} (hb : b ∈ 𝓤 β) : Prod.map inl inl '' a ∪ Prod.map inr inr '' b ∈ 𝓤 (α ⊕ β) := union_mem_sup (image_mem_map ha) (image_mem_map hb)
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
union_mem_uniformity_sum
The union of an entourage of the diagonal in each set of a disjoint union is again an entourage of the diagonal.
Sum.uniformity : 𝓤 (α ⊕ β) = map (Prod.map inl inl) (𝓤 α) ⊔ map (Prod.map inr inr) (𝓤 β) := rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
Sum.uniformity
null
uniformContinuous_inl : UniformContinuous (Sum.inl : α → α ⊕ β) := le_sup_left
lemma
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_inl
null
uniformContinuous_inr : UniformContinuous (Sum.inr : β → α ⊕ β) := le_sup_right
lemma
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
uniformContinuous_inr
null
tendsto_nhds_right {f : Filter β} {u : β → α} {a : α} : Tendsto u f (𝓝 a) ↔ Tendsto (fun x => (a, u x)) f (𝓤 α) := by rw [nhds_eq_comap_uniformity, tendsto_comap_iff]; rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
tendsto_nhds_right
null
tendsto_nhds_left {f : Filter β} {u : β → α} {a : α} : Tendsto u f (𝓝 a) ↔ Tendsto (fun x => (u x, a)) f (𝓤 α) := by rw [nhds_eq_comap_uniformity', tendsto_comap_iff]; rfl
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
tendsto_nhds_left
null
continuousAt_iff'_right [TopologicalSpace β] {f : β → α} {b : β} : ContinuousAt f b ↔ Tendsto (fun x => (f b, f x)) (𝓝 b) (𝓤 α) := by rw [ContinuousAt, tendsto_nhds_right]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuousAt_iff'_right
null
continuousAt_iff'_left [TopologicalSpace β] {f : β → α} {b : β} : ContinuousAt f b ↔ Tendsto (fun x => (f x, f b)) (𝓝 b) (𝓤 α) := by rw [ContinuousAt, tendsto_nhds_left]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuousAt_iff'_left
null
continuousAt_iff_prod [TopologicalSpace β] {f : β → α} {b : β} : ContinuousAt f b ↔ Tendsto (fun x : β × β => (f x.1, f x.2)) (𝓝 (b, b)) (𝓤 α) := ⟨fun H => le_trans (H.prodMap' H) (nhds_le_uniformity _), fun H => continuousAt_iff'_left.2 <| H.comp <| tendsto_id.prodMk_nhds tendsto_const_nhds⟩
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuousAt_iff_prod
null
continuousWithinAt_iff'_right [TopologicalSpace β] {f : β → α} {b : β} {s : Set β} : ContinuousWithinAt f s b ↔ Tendsto (fun x => (f b, f x)) (𝓝[s] b) (𝓤 α) := by rw [ContinuousWithinAt, tendsto_nhds_right]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuousWithinAt_iff'_right
null
continuousWithinAt_iff'_left [TopologicalSpace β] {f : β → α} {b : β} {s : Set β} : ContinuousWithinAt f s b ↔ Tendsto (fun x => (f x, f b)) (𝓝[s] b) (𝓤 α) := by rw [ContinuousWithinAt, tendsto_nhds_left]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuousWithinAt_iff'_left
null
continuousOn_iff'_right [TopologicalSpace β] {f : β → α} {s : Set β} : ContinuousOn f s ↔ ∀ b ∈ s, Tendsto (fun x => (f b, f x)) (𝓝[s] b) (𝓤 α) := by simp [ContinuousOn, continuousWithinAt_iff'_right]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuousOn_iff'_right
null
continuousOn_iff'_left [TopologicalSpace β] {f : β → α} {s : Set β} : ContinuousOn f s ↔ ∀ b ∈ s, Tendsto (fun x => (f x, f b)) (𝓝[s] b) (𝓤 α) := by simp [ContinuousOn, continuousWithinAt_iff'_left]
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuousOn_iff'_left
null
continuous_iff'_right [TopologicalSpace β] {f : β → α} : Continuous f ↔ ∀ b, Tendsto (fun x => (f b, f x)) (𝓝 b) (𝓤 α) := continuous_iff_continuousAt.trans <| forall_congr' fun _ => tendsto_nhds_right
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuous_iff'_right
null
continuous_iff'_left [TopologicalSpace β] {f : β → α} : Continuous f ↔ ∀ b, Tendsto (fun x => (f x, f b)) (𝓝 b) (𝓤 α) := continuous_iff_continuousAt.trans <| forall_congr' fun _ => tendsto_nhds_left
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
continuous_iff'_left
null
exists_is_open_mem_uniformity_of_forall_mem_eq [TopologicalSpace β] {r : Set (α × α)} {s : Set β} {f g : β → α} (hf : ∀ x ∈ s, ContinuousAt f x) (hg : ∀ x ∈ s, ContinuousAt g x) (hfg : s.EqOn f g) (hr : r ∈ 𝓤 α) : ∃ t, IsOpen t ∧ s ⊆ t ∧ ∀ x ∈ t, (f x, g x) ∈ r := by have A : ∀ x ∈ s, ∃ t, IsOpen t ∧ x ∈ t ∧ ∀ z ∈ t, (f z, g z) ∈ r := by intro x hx obtain ⟨t, ht, htsymm, htr⟩ := comp_symm_mem_uniformity_sets hr have A : {z | (f x, f z) ∈ t} ∈ 𝓝 x := (hf x hx).preimage_mem_nhds (mem_nhds_left (f x) ht) have B : {z | (g x, g z) ∈ t} ∈ 𝓝 x := (hg x hx).preimage_mem_nhds (mem_nhds_left (g x) ht) rcases _root_.mem_nhds_iff.1 (inter_mem A B) with ⟨u, hu, u_open, xu⟩ refine ⟨u, u_open, xu, fun y hy ↦ ?_⟩ have I1 : (f y, f x) ∈ t := (htsymm.mk_mem_comm).2 (hu hy).1 have I2 : (g x, g y) ∈ t := (hu hy).2 rw [hfg hx] at I1 exact htr (prodMk_mem_compRel I1 I2) choose! t t_open xt ht using A refine ⟨⋃ x ∈ s, t x, isOpen_biUnion t_open, fun x hx ↦ mem_biUnion hx (xt x hx), ?_⟩ rintro x hx simp only [mem_iUnion, exists_prop] at hx rcases hx with ⟨y, ys, hy⟩ exact ht y ys x hy
lemma
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
exists_is_open_mem_uniformity_of_forall_mem_eq
Consider two functions `f` and `g` which coincide on a set `s` and are continuous there. Then there is an open neighborhood of `s` on which `f` and `g` are uniformly close.
Filter.Tendsto.congr_uniformity {α β} [UniformSpace β] {f g : α → β} {l : Filter α} {b : β} (hf : Tendsto f l (𝓝 b)) (hg : Tendsto (fun x => (f x, g x)) l (𝓤 β)) : Tendsto g l (𝓝 b) := Uniform.tendsto_nhds_right.2 <| (Uniform.tendsto_nhds_right.1 hf).uniformity_trans hg
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
Filter.Tendsto.congr_uniformity
null
Uniform.tendsto_congr {α β} [UniformSpace β] {f g : α → β} {l : Filter α} {b : β} (hfg : Tendsto (fun x => (f x, g x)) l (𝓤 β)) : Tendsto f l (𝓝 b) ↔ Tendsto g l (𝓝 b) := ⟨fun h => h.congr_uniformity hfg, fun h => h.congr_uniformity hfg.uniformity_symm⟩
theorem
Topology
[ "Mathlib.Data.Rel", "Mathlib.Order.Filter.SmallSets", "Mathlib.Topology.UniformSpace.Defs", "Mathlib.Topology.ContinuousOn" ]
Mathlib/Topology/UniformSpace/Basic.lean
Uniform.tendsto_congr
null
Cauchy (f : Filter α) := NeBot f ∧ f ×ˢ f ≤ 𝓤 α
def
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
Cauchy
A filter `f` is Cauchy if for every entourage `r`, there exists an `s ∈ f` such that `s × s ⊆ r`. This is a generalization of Cauchy sequences, because if `a : ℕ → α` then the filter of sets containing cofinitely many of the `a n` is Cauchy iff `a` is a Cauchy sequence.
IsComplete (s : Set α) := ∀ f, Cauchy f → f ≤ 𝓟 s → ∃ x ∈ s, f ≤ 𝓝 x
def
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
IsComplete
A set `s` is called *complete*, if any Cauchy filter `f` such that `s ∈ f` has a limit in `s` (formally, it satisfies `f ≤ 𝓝 x` for some `x ∈ s`).
Filter.HasBasis.cauchy_iff {ι} {p : ι → Prop} {s : ι → Set (α × α)} (h : (𝓤 α).HasBasis p s) {f : Filter α} : Cauchy f ↔ NeBot f ∧ ∀ i, p i → ∃ t ∈ f, ∀ x ∈ t, ∀ y ∈ t, (x, y) ∈ s i := and_congr Iff.rfl <| (f.basis_sets.prod_self.le_basis_iff h).trans <| by simp only [subset_def, Prod.forall, mem_prod_eq, and_imp, id, forall_mem_comm]
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
Filter.HasBasis.cauchy_iff
null
cauchy_iff' {f : Filter α} : Cauchy f ↔ NeBot f ∧ ∀ s ∈ 𝓤 α, ∃ t ∈ f, ∀ x ∈ t, ∀ y ∈ t, (x, y) ∈ s := (𝓤 α).basis_sets.cauchy_iff
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_iff'
null
cauchy_iff {f : Filter α} : Cauchy f ↔ NeBot f ∧ ∀ s ∈ 𝓤 α, ∃ t ∈ f, t ×ˢ t ⊆ s := cauchy_iff'.trans <| by simp only [subset_def, Prod.forall, mem_prod_eq, and_imp, forall_mem_comm]
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_iff
null
cauchy_iff_le {l : Filter α} [hl : l.NeBot] : Cauchy l ↔ l ×ˢ l ≤ 𝓤 α := by simp only [Cauchy, hl, true_and]
lemma
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_iff_le
null
Cauchy.ultrafilter_of {l : Filter α} (h : Cauchy l) : Cauchy (@Ultrafilter.of _ l h.1 : Filter α) := by haveI := h.1 have := Ultrafilter.of_le l exact ⟨Ultrafilter.neBot _, (Filter.prod_mono this this).trans h.2⟩
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
Cauchy.ultrafilter_of
null
cauchy_map_iff {l : Filter β} {f : β → α} : Cauchy (l.map f) ↔ NeBot l ∧ Tendsto (fun p : β × β => (f p.1, f p.2)) (l ×ˢ l) (𝓤 α) := by rw [Cauchy, map_neBot_iff, prod_map_map_eq, Tendsto]
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_map_iff
null
cauchy_map_iff' {l : Filter β} [hl : NeBot l] {f : β → α} : Cauchy (l.map f) ↔ Tendsto (fun p : β × β => (f p.1, f p.2)) (l ×ˢ l) (𝓤 α) := cauchy_map_iff.trans <| and_iff_right hl
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_map_iff'
null
Cauchy.mono {f g : Filter α} [hg : NeBot g] (h_c : Cauchy f) (h_le : g ≤ f) : Cauchy g := ⟨hg, le_trans (Filter.prod_mono h_le h_le) h_c.right⟩
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
Cauchy.mono
null
Cauchy.mono' {f g : Filter α} (h_c : Cauchy f) (_ : NeBot g) (h_le : g ≤ f) : Cauchy g := h_c.mono h_le
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
Cauchy.mono'
null
cauchy_nhds {a : α} : Cauchy (𝓝 a) := ⟨nhds_neBot, nhds_prod_eq.symm.trans_le (nhds_le_uniformity a)⟩
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_nhds
null
cauchy_pure {a : α} : Cauchy (pure a) := cauchy_nhds.mono (pure_le_nhds a)
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_pure
null
Filter.Tendsto.cauchy_map {l : Filter β} [NeBot l] {f : β → α} {a : α} (h : Tendsto f l (𝓝 a)) : Cauchy (map f l) := cauchy_nhds.mono h
theorem
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
Filter.Tendsto.cauchy_map
null
Cauchy.mono_uniformSpace {u v : UniformSpace β} {F : Filter β} (huv : u ≤ v) (hF : Cauchy (uniformSpace := u) F) : Cauchy (uniformSpace := v) F := ⟨hF.1, hF.2.trans huv⟩
lemma
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
Cauchy.mono_uniformSpace
null
cauchy_inf_uniformSpace {u v : UniformSpace β} {F : Filter β} : Cauchy (uniformSpace := u ⊓ v) F ↔ Cauchy (uniformSpace := u) F ∧ Cauchy (uniformSpace := v) F := by unfold Cauchy rw [inf_uniformity (u := u), le_inf_iff, and_and_left]
lemma
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_inf_uniformSpace
null
cauchy_iInf_uniformSpace {ι : Sort*} [Nonempty ι] {u : ι → UniformSpace β} {l : Filter β} : Cauchy (uniformSpace := ⨅ i, u i) l ↔ ∀ i, Cauchy (uniformSpace := u i) l := by unfold Cauchy rw [iInf_uniformity, le_iInf_iff, forall_and, forall_const]
lemma
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_iInf_uniformSpace
null
cauchy_iInf_uniformSpace' {ι : Sort*} {u : ι → UniformSpace β} {l : Filter β} [l.NeBot] : Cauchy (uniformSpace := ⨅ i, u i) l ↔ ∀ i, Cauchy (uniformSpace := u i) l := by simp_rw [cauchy_iff_le (uniformSpace := _), iInf_uniformity, le_iInf_iff]
lemma
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_iInf_uniformSpace'
null
cauchy_comap_uniformSpace {u : UniformSpace β} {α} {f : α → β} {l : Filter α} : Cauchy (uniformSpace := comap f u) l ↔ Cauchy (map f l) := by simp only [Cauchy, map_neBot_iff, prod_map_map_eq, map_le_iff_le_comap] rfl
lemma
Topology
[ "Mathlib.Topology.Algebra.Constructions", "Mathlib.Topology.Bases", "Mathlib.Algebra.Order.Group.Nat", "Mathlib.Topology.UniformSpace.DiscreteUniformity" ]
Mathlib/Topology/UniformSpace/Cauchy.lean
cauchy_comap_uniformSpace
null