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_root_.StarAlgHom.ext_topologicalClosure [T2Space B] {S : StarSubalgebra R A} {φ ψ : S.topologicalClosure →⋆ₐ[R] B} (hφ : Continuous φ) (hψ : Continuous ψ) (h : φ.comp (inclusion (le_topologicalClosure S)) = ψ.comp (inclusion (le_topologicalClosure S))) : φ = ψ := by rw [DFunLike.ext'_iff] have : DenseRange (Set.inclusion (le_topologicalClosure S)) := by simp [-SetLike.coe_sort_coe] refine Continuous.ext_on this hφ hψ ?_ rintro _ ⟨x, rfl⟩ simpa only using DFunLike.congr_fun h x
theorem
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
_root_.StarAlgHom.ext_topologicalClosure
Continuous `StarAlgHom`s from the topological closure of a `StarSubalgebra` whose compositions with the `StarSubalgebra.inclusion` map agree are, in fact, equal.
_root_.StarAlgHomClass.ext_topologicalClosure [T2Space B] {F : Type*} {S : StarSubalgebra R A} [FunLike F S.topologicalClosure B] [AlgHomClass F R S.topologicalClosure B] [StarHomClass F S.topologicalClosure B] {φ ψ : F} (hφ : Continuous φ) (hψ : Continuous ψ) (h : ∀ x : S, φ (inclusion (le_topologicalClosure S) x) = ψ ((inclusion (le_topologicalClosure S)) x)) : φ = ψ := by have : (φ : S.topologicalClosure →⋆ₐ[R] B) = (ψ : S.topologicalClosure →⋆ₐ[R] B) := by refine StarAlgHom.ext_topologicalClosure (R := R) (A := A) (B := B) hφ hψ (StarAlgHom.ext ?_) simpa only [StarAlgHom.coe_comp, StarAlgHom.coe_coe] using h rw [DFunLike.ext'_iff, ← StarAlgHom.coe_coe] apply congrArg _ this
theorem
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
_root_.StarAlgHomClass.ext_topologicalClosure
null
elemental (x : A) : StarSubalgebra R A := (adjoin R ({x} : Set A)).topologicalClosure
def
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
elemental
The topological closure of the star subalgebra generated by a single element.
self_mem (x : A) : x ∈ elemental R x := le_topologicalClosure _ (self_mem_adjoin_singleton R x) @[simp, aesop safe (rule_sets := [SetLike])]
theorem
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
self_mem
null
star_self_mem (x : A) : star x ∈ elemental R x := star_mem <| self_mem R x
theorem
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
star_self_mem
null
isClosedEmbedding_coe (x : A) : IsClosedEmbedding ((↑) : elemental R x → A) where eq_induced := rfl injective := Subtype.coe_injective isClosed_range := by simpa using isClosed R x
theorem
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
isClosedEmbedding_coe
The `elemental` star subalgebra generated by a normal element is commutative. -/ instance [T2Space A] {x : A} [IsStarNormal x] : CommSemiring (elemental R x) := StarSubalgebra.commSemiringTopologicalClosure _ mul_comm /-- The `elemental` generated by a normal element is commutative. -/ instance {R A} [CommRing R] [StarRing R] [TopologicalSpace A] [Ring A] [Algebra R A] [StarRing A] [StarModule R A] [IsTopologicalRing A] [ContinuousStar A] [T2Space A] {x : A} [IsStarNormal x] : CommRing (elemental R x) := StarSubalgebra.commRingTopologicalClosure _ mul_comm theorem isClosed (x : A) : IsClosed (elemental R x : Set A) := isClosed_closure instance {A : Type*} [UniformSpace A] [CompleteSpace A] [Semiring A] [StarRing A] [IsTopologicalSemiring A] [ContinuousStar A] [Algebra R A] [StarModule R A] (x : A) : CompleteSpace (elemental R x) := isClosed_closure.completeSpace_coe variable {R} in theorem le_of_mem {S : StarSubalgebra R A} (hS : IsClosed (S : Set A)) {x : A} (hx : x ∈ S) : elemental R x ≤ S := topologicalClosure_minimal (adjoin_le <| Set.singleton_subset_iff.2 hx) hS variable {R} in theorem le_iff_mem {x : A} {s : StarSubalgebra R A} (hs : IsClosed (s : Set A)) : elemental R x ≤ s ↔ x ∈ s := ⟨fun h ↦ h (self_mem R x), fun h ↦ le_of_mem hs h⟩ /-- The coercion from an elemental algebra to the full algebra as a `IsClosedEmbedding`.
le_centralizer_centralizer [T2Space A] (x : A) : elemental R x ≤ centralizer R (centralizer R {x}) := topologicalClosure_adjoin_le_centralizer_centralizer .. @[elab_as_elim]
lemma
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
le_centralizer_centralizer
null
induction_on {x y : A} (hy : y ∈ elemental R x) {P : (u : A) → u ∈ elemental R x → Prop} (self : P x (self_mem R x)) (star_self : P (star x) (star_self_mem R x)) (algebraMap : ∀ r, P (algebraMap R A r) (_root_.algebraMap_mem _ r)) (add : ∀ u hu v hv, P u hu → P v hv → P (u + v) (add_mem hu hv)) (mul : ∀ u hu v hv, P u hu → P v hv → P (u * v) (mul_mem hu hv)) (closure : ∀ s : Set A, (hs : s ⊆ elemental R x) → (∀ u, (hu : u ∈ s) → P u (hs hu)) → ∀ v, (hv : v ∈ closure s) → P v (closure_minimal hs (isClosed R x) hv)) : P y hy := by apply closure (adjoin R {x} : Set A) subset_closure (fun y hy ↦ ?_) y hy rw [SetLike.mem_coe, ← mem_toSubalgebra, adjoin_toSubalgebra] at hy induction hy using Algebra.adjoin_induction with | mem u hu => obtain ((rfl : u = x) | (hu : star u = x)) := by simpa using hu · exact self · simp_rw [← hu, star_star] at star_self exact star_self | algebraMap r => exact algebraMap r | add u v hu_mem hv_mem hu hv => exact add u (subset_closure hu_mem) v (subset_closure hv_mem) (hu hu_mem) (hv hv_mem) | mul u v hu_mem hv_mem hu hv => exact mul u (subset_closure hu_mem) v (subset_closure hv_mem) (hu hu_mem) (hv hv_mem)
theorem
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
induction_on
null
starAlgHomClass_ext [T2Space B] {F : Type*} {a : A} [FunLike F (elemental R a) B] [AlgHomClass F R _ B] [StarHomClass F _ B] {φ ψ : F} (hφ : Continuous φ) (hψ : Continuous ψ) (h : φ ⟨a, self_mem R a⟩ = ψ ⟨a, self_mem R a⟩) : φ = ψ := by refine StarAlgHomClass.ext_topologicalClosure hφ hψ fun x => ?_ refine adjoin_induction_subtype x ?_ ?_ ?_ ?_ ?_ exacts [fun y hy => by simpa only [Set.mem_singleton_iff.mp hy] using h, fun r => by simp only [AlgHomClass.commutes], fun x y hx hy => by simp only [map_add, hx, hy], fun x y hx hy => by simp only [map_mul, hx, hy], fun x hx => by simp only [map_star, hx]]
theorem
Topology
[ "Mathlib.Algebra.Star.Subalgebra", "Mathlib.Topology.Algebra.Algebra", "Mathlib.Topology.Algebra.Star" ]
Mathlib/Topology/Algebra/StarSubalgebra.lean
starAlgHomClass_ext
null
@[to_additive /-- The topological support of a function is the closure of its support. i.e. the closure of the set of all elements where the function is nonzero. -/] mulTSupport (f : X → α) : Set X := closure (mulSupport f) @[to_additive]
def
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
mulTSupport
The topological support of a function is the closure of its support, i.e. the closure of the set of all elements where the function is not equal to 1.
subset_mulTSupport (f : X → α) : mulSupport f ⊆ mulTSupport f := subset_closure @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
subset_mulTSupport
null
isClosed_mulTSupport (f : X → α) : IsClosed (mulTSupport f) := isClosed_closure @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
isClosed_mulTSupport
null
mulTSupport_eq_empty_iff {f : X → α} : mulTSupport f = ∅ ↔ f = 1 := by rw [mulTSupport, closure_empty_iff, mulSupport_eq_empty_iff] @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
mulTSupport_eq_empty_iff
null
image_eq_one_of_notMem_mulTSupport {f : X → α} {x : X} (hx : x ∉ mulTSupport f) : f x = 1 := mulSupport_subset_iff'.mp (subset_mulTSupport f) x hx @[deprecated (since := "2025-05-24")] alias image_eq_zero_of_nmem_tsupport := image_eq_zero_of_notMem_tsupport @[to_additive existing, deprecated (since := "2025-05-24")] alias image_eq_one_of_nmem_mulTSupport := image_eq_one_of_notMem_mulTSupport @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
image_eq_one_of_notMem_mulTSupport
null
range_subset_insert_image_mulTSupport (f : X → α) : range f ⊆ insert 1 (f '' mulTSupport f) := by grw [← subset_mulTSupport f]; exact range_subset_insert_image_mulSupport f @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
range_subset_insert_image_mulTSupport
null
range_eq_image_mulTSupport_or (f : X → α) : range f = f '' mulTSupport f ∨ range f = insert 1 (f '' mulTSupport f) := (wcovBy_insert _ _).eq_or_eq (image_subset_range _ _) (range_subset_insert_image_mulTSupport f)
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
range_eq_image_mulTSupport_or
null
tsupport_mul_subset_left {α : Type*} [MulZeroClass α] {f g : X → α} : (tsupport fun x => f x * g x) ⊆ tsupport f := closure_mono (support_mul_subset_left _ _)
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
tsupport_mul_subset_left
null
tsupport_mul_subset_right {α : Type*} [MulZeroClass α] {f g : X → α} : (tsupport fun x => f x * g x) ⊆ tsupport g := closure_mono (support_mul_subset_right _ _)
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
tsupport_mul_subset_right
null
tsupport_smul_subset_left {M α} [TopologicalSpace X] [Zero M] [Zero α] [SMulWithZero M α] (f : X → M) (g : X → α) : (tsupport fun x => f x • g x) ⊆ tsupport f := closure_mono <| support_smul_subset_left f g
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
tsupport_smul_subset_left
null
tsupport_smul_subset_right {M α} [TopologicalSpace X] [Zero α] [SMulZeroClass M α] (f : X → M) (g : X → α) : (tsupport fun x => f x • g x) ⊆ tsupport g := closure_mono <| support_smul_subset_right f g @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
tsupport_smul_subset_right
null
mulTSupport_mul [TopologicalSpace X] [MulOneClass α] {f g : X → α} : (mulTSupport fun x ↦ f x * g x) ⊆ mulTSupport f ∪ mulTSupport g := closure_minimal ((mulSupport_mul f g).trans (union_subset_union (subset_mulTSupport _) (subset_mulTSupport _))) (isClosed_closure.union isClosed_closure)
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
mulTSupport_mul
null
@[to_additive] notMem_mulTSupport_iff_eventuallyEq : x ∉ mulTSupport f ↔ f =ᶠ[𝓝 x] 1 := by simp_rw [mulTSupport, mem_closure_iff_nhds, not_forall, not_nonempty_iff_eq_empty, exists_prop, ← disjoint_iff_inter_eq_empty, disjoint_mulSupport_iff, eventuallyEq_iff_exists_mem] @[deprecated (since := "2025-05-23")] alias not_mem_tsupport_iff_eventuallyEq := notMem_tsupport_iff_eventuallyEq @[to_additive existing, deprecated (since := "2025-05-23")] alias not_mem_mulTSupport_iff_eventuallyEq := notMem_mulTSupport_iff_eventuallyEq @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
notMem_mulTSupport_iff_eventuallyEq
null
continuous_of_mulTSupport [TopologicalSpace β] {f : α → β} (hf : ∀ x ∈ mulTSupport f, ContinuousAt f x) : Continuous f := continuous_iff_continuousAt.2 fun x => (em _).elim (hf x) fun hx => (@continuousAt_const _ _ _ _ _ 1).congr (notMem_mulTSupport_iff_eventuallyEq.mp hx).symm @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
continuous_of_mulTSupport
null
ContinuousOn.continuous_of_mulTSupport_subset [TopologicalSpace β] {f : α → β} {s : Set α} (hs : ContinuousOn f s) (h's : IsOpen s) (h''s : mulTSupport f ⊆ s) : Continuous f := continuous_of_mulTSupport fun _ hx ↦ h's.continuousOn_iff.mp hs <| h''s hx
lemma
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
ContinuousOn.continuous_of_mulTSupport_subset
null
@[to_additive /-- A function `f` *has compact support* or is *compactly supported* if the closure of the support of `f` is compact. In a T₂ space this is equivalent to `f` being equal to `0` outside a compact set. -/] HasCompactMulSupport (f : α → β) : Prop := IsCompact (mulTSupport f) @[to_additive]
def
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactMulSupport
A function `f` *has compact multiplicative support* or is *compactly supported* if the closure of the multiplicative support of `f` is compact. In a T₂ space this is equivalent to `f` being equal to `1` outside a compact set.
hasCompactMulSupport_def : HasCompactMulSupport f ↔ IsCompact (closure (mulSupport f)) := by rfl @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
hasCompactMulSupport_def
null
exists_compact_iff_hasCompactMulSupport [R1Space α] : (∃ K : Set α, IsCompact K ∧ ∀ x, x ∉ K → f x = 1) ↔ HasCompactMulSupport f := by simp_rw [← notMem_mulSupport, ← mem_compl_iff, ← subset_def, compl_subset_compl, hasCompactMulSupport_def, exists_isCompact_superset_iff]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
exists_compact_iff_hasCompactMulSupport
null
@[to_additive] intro [R1Space α] (hK : IsCompact K) (hfK : ∀ x, x ∉ K → f x = 1) : HasCompactMulSupport f := exists_compact_iff_hasCompactMulSupport.mp ⟨K, hK, hfK⟩ @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
intro
null
intro' (hK : IsCompact K) (h'K : IsClosed K) (hfK : ∀ x, x ∉ K → f x = 1) : HasCompactMulSupport f := by have : mulTSupport f ⊆ K := by rw [← h'K.closure_eq] apply closure_mono (mulSupport_subset_iff'.2 hfK) exact IsCompact.of_isClosed_subset hK ( isClosed_mulTSupport f) this @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
intro'
null
of_mulSupport_subset_isCompact [R1Space α] (hK : IsCompact K) (h : mulSupport f ⊆ K) : HasCompactMulSupport f := hK.closure_of_subset h @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
of_mulSupport_subset_isCompact
null
isCompact (hf : HasCompactMulSupport f) : IsCompact (mulTSupport f) := hf @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
isCompact
null
_root_.hasCompactMulSupport_iff_eventuallyEq : HasCompactMulSupport f ↔ f =ᶠ[coclosedCompact α] 1 := mem_coclosedCompact_iff.symm @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
_root_.hasCompactMulSupport_iff_eventuallyEq
null
_root_.isCompact_range_of_mulSupport_subset_isCompact [TopologicalSpace β] (hf : Continuous f) (hk : IsCompact K) (h'f : mulSupport f ⊆ K) : IsCompact (range f) := by rcases range_eq_image_or_of_mulSupport_subset h'f with h2 | h2 <;> rw [h2] exacts [hk.image hf, (hk.image hf).insert 1] @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
_root_.isCompact_range_of_mulSupport_subset_isCompact
null
isCompact_range [TopologicalSpace β] (h : HasCompactMulSupport f) (hf : Continuous f) : IsCompact (range f) := isCompact_range_of_mulSupport_subset_isCompact hf h (subset_mulTSupport f) @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
isCompact_range
null
mono' {f' : α → γ} (hf : HasCompactMulSupport f) (hff' : mulSupport f' ⊆ mulTSupport f) : HasCompactMulSupport f' := IsCompact.of_isClosed_subset hf isClosed_closure <| closure_minimal hff' isClosed_closure @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
mono'
null
mono {f' : α → γ} (hf : HasCompactMulSupport f) (hff' : mulSupport f' ⊆ mulSupport f) : HasCompactMulSupport f' := hf.mono' <| hff'.trans subset_closure @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
mono
null
comp_left (hf : HasCompactMulSupport f) (hg : g 1 = 1) : HasCompactMulSupport (g ∘ f) := hf.mono <| mulSupport_comp_subset hg f @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
comp_left
null
_root_.hasCompactMulSupport_comp_left (hg : ∀ {x}, g x = 1 ↔ x = 1) : HasCompactMulSupport (g ∘ f) ↔ HasCompactMulSupport f := by simp_rw [hasCompactMulSupport_def, mulSupport_comp_eq g (@hg) f] @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
_root_.hasCompactMulSupport_comp_left
null
comp_isClosedEmbedding (hf : HasCompactMulSupport f) {g : α' → α} (hg : IsClosedEmbedding g) : HasCompactMulSupport (f ∘ g) := by rw [hasCompactMulSupport_def, Function.mulSupport_comp_eq_preimage] refine IsCompact.of_isClosed_subset (hg.isCompact_preimage hf) isClosed_closure ?_ rw [hg.isEmbedding.closure_eq_preimage_closure_image] exact preimage_mono (closure_mono <| image_preimage_subset _ _) @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
comp_isClosedEmbedding
null
comp₂_left (hf : HasCompactMulSupport f) (hf₂ : HasCompactMulSupport f₂) (hm : m 1 1 = 1) : HasCompactMulSupport fun x => m (f x) (f₂ x) := by rw [hasCompactMulSupport_iff_eventuallyEq] at hf hf₂ ⊢ filter_upwards [hf, hf₂] with x hx hx₂ simp_rw [hx, hx₂, Pi.one_apply, hm] @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
comp₂_left
null
isCompact_preimage [TopologicalSpace β] {K : Set β} (h'f : HasCompactMulSupport f) (hf : Continuous f) (hk : IsClosed K) (h'k : 1 ∉ K) : IsCompact (f ⁻¹' K) := by apply IsCompact.of_isClosed_subset h'f (hk.preimage hf) (fun x hx ↦ ?_) apply subset_mulTSupport aesop variable [T2Space α']
lemma
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
isCompact_preimage
null
@[to_additive] mulTSupport_extend_one_subset : mulTSupport (g.extend f 1) ⊆ g '' mulTSupport f := (hf.image cont).isClosed.closure_subset_iff.mpr <| mulSupport_extend_one_subset.trans (image_mono subset_closure) @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
mulTSupport_extend_one_subset
null
extend_one : HasCompactMulSupport (g.extend f 1) := HasCompactMulSupport.of_mulSupport_subset_isCompact (hf.image cont) (subset_closure.trans <| hf.mulTSupport_extend_one_subset cont) @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
extend_one
null
mulTSupport_extend_one (inj : g.Injective) : mulTSupport (g.extend f 1) = g '' mulTSupport f := (hf.mulTSupport_extend_one_subset cont).antisymm <| (image_closure_subset_closure_image cont).trans (closure_mono (mulSupport_extend_one inj).superset)
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
mulTSupport_extend_one
null
@[to_additive] continuous_extend_one [TopologicalSpace β] {U : Set α'} (hU : IsOpen U) {f : U → β} (cont : Continuous f) (supp : HasCompactMulSupport f) : Continuous (Subtype.val.extend f 1) := continuous_of_mulTSupport fun x h ↦ by rw [show x = ↑(⟨x, Subtype.coe_image_subset _ _ (supp.mulTSupport_extend_one_subset continuous_subtype_val h)⟩ : U) by rfl, ← (hU.isOpenEmbedding_subtypeVal).continuousAt_iff, extend_comp Subtype.val_injective] exact cont.continuousAt
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
continuous_extend_one
null
@[to_additive /-- If `f` has compact support, then `f` tends to zero at infinity. -/] is_one_at_infty {f : α → γ} [TopologicalSpace γ] (h : HasCompactMulSupport f) : Tendsto f (cocompact α) (𝓝 1) := by intro N hN rw [mem_map, mem_cocompact'] refine ⟨mulTSupport f, h.isCompact, ?_⟩ rw [compl_subset_comm] intro v hv rw [mem_preimage, image_eq_one_of_notMem_mulTSupport hv] exact mem_of_mem_nhds hN
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
is_one_at_infty
If `f` has compact multiplicative support, then `f` tends to 1 at infinity.
@[to_additive] HasCompactMulSupport.of_compactSpace (f : α → γ) : HasCompactMulSupport f := IsCompact.of_isClosed_subset isCompact_univ (isClosed_mulTSupport f) (Set.subset_univ (mulTSupport f))
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactMulSupport.of_compactSpace
In a compact space `α`, any function has compact support.
@[to_additive] HasCompactMulSupport.mul (hf : HasCompactMulSupport f) (hf' : HasCompactMulSupport f') : HasCompactMulSupport (f * f') := hf.comp₂_left hf' (mul_one 1) @[to_additive, simp]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactMulSupport.mul
null
protected HasCompactMulSupport.one {α β : Type*} [TopologicalSpace α] [One β] : HasCompactMulSupport (1 : α → β) := by simp [HasCompactMulSupport, mulTSupport]
lemma
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactMulSupport.one
null
@[to_additive] protected HasCompactMulSupport.inv {α β : Type*} [TopologicalSpace α] [DivisionMonoid β] {f : α → β} (hf : HasCompactMulSupport f) : HasCompactMulSupport (f⁻¹) := by simpa only [HasCompactMulSupport, mulTSupport, mulSupport_inv] using hf @[deprecated (since := "2025-07-31")] alias HasCompactSupport.neg' := HasCompactSupport.neg @[deprecated (since := "2025-07-31")] alias HasCompactMulSupport.inv' := HasCompactMulSupport.inv @[to_additive]
lemma
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactMulSupport.inv
null
HasCompactSupport.div {α β : Type*} [TopologicalSpace α] [DivisionMonoid β] {f f' : α → β} (hf : HasCompactMulSupport f) (hf' : HasCompactMulSupport f') : HasCompactMulSupport (f / f') := div_eq_mul_inv f f' ▸ hf.mul hf'.inv
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactSupport.div
null
HasCompactSupport.smul_left (hf : HasCompactSupport f') : HasCompactSupport (f • f') := by rw [hasCompactSupport_iff_eventuallyEq] at hf ⊢ exact hf.mono fun x hx => by simp_rw [Pi.smul_apply', hx, Pi.zero_apply, smul_zero]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactSupport.smul_left
null
HasCompactSupport.smul_right (hf : HasCompactSupport f) : HasCompactSupport (f • f') := by rw [hasCompactSupport_iff_eventuallyEq] at hf ⊢ exact hf.mono fun x hx => by simp_rw [Pi.smul_apply', hx, Pi.zero_apply, zero_smul]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactSupport.smul_right
null
HasCompactSupport.mul_right (hf : HasCompactSupport f) : HasCompactSupport (f * f') := by rw [hasCompactSupport_iff_eventuallyEq] at hf ⊢ exact hf.mono fun x hx => by simp_rw [Pi.mul_apply, hx, Pi.zero_apply, zero_mul]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactSupport.mul_right
null
HasCompactSupport.mul_left (hf : HasCompactSupport f') : HasCompactSupport (f * f') := by rw [hasCompactSupport_iff_eventuallyEq] at hf ⊢ exact hf.mono fun x hx => by simp_rw [Pi.mul_apply, hx, Pi.zero_apply, mul_zero]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactSupport.mul_left
null
protected HasCompactSupport.abs {f : α → β} (hf : HasCompactSupport f) : HasCompactSupport |f| := hf.comp_left (g := abs) abs_zero
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactSupport.abs
null
@[to_additive /-- If a family of functions `f` has locally-finite support, subordinate to a family of open sets, then for any point we can find a neighbourhood on which only finitely-many members of `f` are non-zero. -/] LocallyFinite.exists_finset_nhds_mulSupport_subset {U : ι → Set X} [One R] {f : ι → X → R} (hlf : LocallyFinite fun i => mulSupport (f i)) (hso : ∀ i, mulTSupport (f i) ⊆ U i) (ho : ∀ i, IsOpen (U i)) (x : X) : ∃ (is : Finset ι), ∃ n, n ∈ 𝓝 x ∧ (n ⊆ ⋂ i ∈ is, U i) ∧ ∀ z ∈ n, (mulSupport fun i => f i z) ⊆ is := by obtain ⟨n, hn, hnf⟩ := hlf x classical let is := {i ∈ hnf.toFinset | x ∈ U i} let js := {j ∈ hnf.toFinset | x ∉ U j} refine ⟨is, (n ∩ ⋂ j ∈ js, (mulTSupport (f j))ᶜ) ∩ ⋂ i ∈ is, U i, inter_mem (inter_mem hn ?_) ?_, inter_subset_right, fun z hz => ?_⟩ · exact (biInter_finset_mem js).mpr fun j hj => IsClosed.compl_mem_nhds (isClosed_mulTSupport _) (Set.notMem_subset (hso j) (Finset.mem_filter.mp hj).2) · exact (biInter_finset_mem is).mpr fun i hi => (ho i).mem_nhds (Finset.mem_filter.mp hi).2 · have hzn : z ∈ n := by rw [inter_assoc] at hz exact mem_of_mem_inter_left hz replace hz := mem_of_mem_inter_right (mem_of_mem_inter_left hz) simp only [js, Finset.mem_filter, Finite.mem_toFinset, mem_setOf_eq, mem_iInter, and_imp] at hz suffices (mulSupport fun i => f i z) ⊆ hnf.toFinset by refine hnf.toFinset.subset_coe_filter_of_subset_forall _ this fun i hi => ?_ specialize hz i ⟨z, ⟨hi, hzn⟩⟩ contrapose hz simp [hz, subset_mulTSupport (f i) hi] intro i hi simp only [Finite.coe_toFinset, mem_setOf_eq] exact ⟨z, ⟨hi, hzn⟩⟩ @[deprecated (since := "2025-05-22")] alias LocallyFinite.exists_finset_nhd_mulSupport_subset := LocallyFinite.exists_finset_nhds_mulSupport_subset @[deprecated (since := "2025-05-22")] alias LocallyFinite.exists_finset_nhd_support_subset := LocallyFinite.exists_finset_nhds_support_subset @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
LocallyFinite.exists_finset_nhds_mulSupport_subset
If a family of functions `f` has locally-finite multiplicative support, subordinate to a family of open sets, then for any point we can find a neighbourhood on which only finitely-many members of `f` are not equal to 1.
locallyFinite_mulSupport_iff [One M] {f : ι → X → M} : (LocallyFinite fun i ↦ mulSupport <| f i) ↔ LocallyFinite fun i ↦ mulTSupport <| f i := ⟨LocallyFinite.closure, fun H ↦ H.subset fun _ ↦ subset_closure⟩
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
locallyFinite_mulSupport_iff
null
LocallyFinite.smul_left [Zero R] [Zero M] [SMulWithZero R M] {s : ι → X → R} (h : LocallyFinite fun i ↦ support <| s i) (f : ι → X → M) : LocallyFinite fun i ↦ support <| s i • f i := h.subset fun i x ↦ mt <| fun h ↦ by rw [Pi.smul_apply', h, zero_smul]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
LocallyFinite.smul_left
null
LocallyFinite.smul_right [Zero M] [SMulZeroClass R M] {f : ι → X → M} (h : LocallyFinite fun i ↦ support <| f i) (s : ι → X → R) : LocallyFinite fun i ↦ support <| s i • f i := h.subset fun i x ↦ mt <| fun h ↦ by rw [Pi.smul_apply', h, smul_zero]
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
LocallyFinite.smul_right
null
@[to_additive] HasCompactMulSupport.comp_homeomorph {M} [One M] {f : Y → M} (hf : HasCompactMulSupport f) (φ : X ≃ₜ Y) : HasCompactMulSupport (f ∘ φ) := hf.comp_isClosedEmbedding φ.isClosedEmbedding
theorem
Topology
[ "Mathlib.Algebra.GroupWithZero.Indicator", "Mathlib.Algebra.Module.Basic", "Mathlib.Algebra.Order.Group.Unbundled.Abs", "Mathlib.Topology.Homeomorph.Defs", "Mathlib.Topology.Separation.Hausdorff" ]
Mathlib/Topology/Algebra/Support.lean
HasCompactMulSupport.comp_homeomorph
null
IsTopologicallyNilpotent {R : Type*} [MonoidWithZero R] [TopologicalSpace R] (a : R) : Prop := Tendsto (a ^ ·) atTop (𝓝 0)
def
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
IsTopologicallyNilpotent
An element is topologically nilpotent if its powers converge to `0`.
map {F : Type*} [FunLike F R S] [MonoidWithZeroHomClass F R S] {φ : F} (hφ : Continuous φ) {a : R} (ha : IsTopologicallyNilpotent a) : IsTopologicallyNilpotent (φ a) := by unfold IsTopologicallyNilpotent at ha ⊢ simp_rw [← map_pow] exact (map_zero φ ▸ hφ.tendsto 0).comp ha
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
map
The image of a topologically nilpotent element under a continuous morphism is topologically nilpotent
zero : IsTopologicallyNilpotent (0 : R) := tendsto_atTop_of_eventually_const (i₀ := 1) (fun _ hi => by rw [zero_pow (Nat.ne_zero_iff_zero_lt.mpr hi)])
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
zero
`0` is topologically nilpotent
_root_.IsNilpotent.isTopologicallyNilpotent {a : R} (ha : IsNilpotent a) : IsTopologicallyNilpotent a := by obtain ⟨n, hn⟩ := ha apply tendsto_atTop_of_eventually_const (i₀ := n) intro i hi rw [← Nat.add_sub_of_le hi, pow_add, hn, zero_mul]
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
_root_.IsNilpotent.isTopologicallyNilpotent
null
exists_pow_mem_of_mem_nhds {a : R} (ha : IsTopologicallyNilpotent a) {v : Set R} (hv : v ∈ 𝓝 0) : ∃ n, a ^ n ∈ v := (ha.eventually_mem hv).exists
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
exists_pow_mem_of_mem_nhds
null
mul_right_of_commute [IsLinearTopology Rᵐᵒᵖ R] {a b : R} (ha : IsTopologicallyNilpotent a) (hab : Commute a b) : IsTopologicallyNilpotent (a * b) := by simp_rw [IsTopologicallyNilpotent, hab.mul_pow] exact IsLinearTopology.tendsto_mul_zero_of_left _ _ ha
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
mul_right_of_commute
If `a` and `b` commute and `a` is topologically nilpotent, then `a * b` is topologically nilpotent.
mul_left_of_commute [IsLinearTopology R R] {a b : R} (hb : IsTopologicallyNilpotent b) (hab : Commute a b) : IsTopologicallyNilpotent (a * b) := by simp_rw [IsTopologicallyNilpotent, hab.mul_pow] exact IsLinearTopology.tendsto_mul_zero_of_right _ _ hb
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
mul_left_of_commute
If `a` and `b` commute and `b` is topologically nilpotent, then `a * b` is topologically nilpotent.
add_of_commute [IsLinearTopology R R] {a b : R} (ha : IsTopologicallyNilpotent a) (hb : IsTopologicallyNilpotent b) (h : Commute a b) : IsTopologicallyNilpotent (a + b) := by simp only [IsTopologicallyNilpotent, atTop_basis.tendsto_iff IsLinearTopology.hasBasis_ideal, true_and] intro I I_mem_nhds obtain ⟨na, ha⟩ := ha.exists_pow_mem_of_mem_nhds I_mem_nhds obtain ⟨nb, hb⟩ := hb.exists_pow_mem_of_mem_nhds I_mem_nhds exact ⟨na + nb, fun m hm ↦ I.add_pow_mem_of_pow_mem_of_le_of_commute ha hb (le_trans hm (Nat.le_add_right _ _)) h⟩
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
add_of_commute
If `a` and `b` are topologically nilpotent and commute, then `a + b` is topologically nilpotent.
mul_right {a : R} (ha : IsTopologicallyNilpotent a) (b : R) : IsTopologicallyNilpotent (a * b) := ha.mul_right_of_commute (Commute.all ..)
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
mul_right
If `a` is topologically nilpotent, then `a * b` is topologically nilpotent.
mul_left (a : R) {b : R} (hb : IsTopologicallyNilpotent b) : IsTopologicallyNilpotent (a * b) := hb.mul_left_of_commute (Commute.all ..)
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
mul_left
If `b` is topologically nilpotent, then `a * b` is topologically nilpotent.
add {a b : R} (ha : IsTopologicallyNilpotent a) (hb : IsTopologicallyNilpotent b) : IsTopologicallyNilpotent (a + b) := ha.add_of_commute hb (Commute.all ..) variable (R) in
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
add
If `a` and `b` are topologically nilpotent, then `a + b` is topologically nilpotent.
@[simps] _root_.topologicalNilradical : Ideal R where carrier := {a | IsTopologicallyNilpotent a} add_mem' := add zero_mem' := zero smul_mem' := mul_left
def
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
_root_.topologicalNilradical
The topological nilradical of a ring with a linear topology
mem_topologicalNilradical_iff {a : R} : a ∈ topologicalNilradical R ↔ IsTopologicallyNilpotent a := by simp [topologicalNilradical]
theorem
Topology
[ "Mathlib.Topology.Algebra.LinearTopology", "Mathlib.RingTheory.Ideal.Basic", "Mathlib.RingTheory.Nilpotent.Defs" ]
Mathlib/Topology/Algebra/TopologicallyNilpotent.lean
mem_topologicalNilradical_iff
null
@[to_additive (attr := simp)] UniformFun.toFun_one [One β] : toFun (1 : α →ᵤ β) = 1 := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.toFun_one
null
UniformFun.ofFun_one [One β] : ofFun (1 : α → β) = 1 := rfl @[to_additive] instance [One β] : One (α →ᵤ[𝔖] β) := Pi.instOne @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.ofFun_one
null
UniformOnFun.toFun_one [One β] : toFun 𝔖 (1 : α →ᵤ[𝔖] β) = 1 := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.toFun_one
null
UniformOnFun.one_apply [One β] : ofFun 𝔖 (1 : α → β) = 1 := rfl @[to_additive] instance [Mul β] : Mul (α →ᵤ β) := Pi.instMul @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.one_apply
null
UniformFun.toFun_mul [Mul β] (f g : α →ᵤ β) : toFun (f * g) = toFun f * toFun g := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.toFun_mul
null
UniformFun.ofFun_mul [Mul β] (f g : α → β) : ofFun (f * g) = ofFun f * ofFun g := rfl @[to_additive] instance [Mul β] : Mul (α →ᵤ[𝔖] β) := Pi.instMul @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.ofFun_mul
null
UniformOnFun.toFun_mul [Mul β] (f g : α →ᵤ[𝔖] β) : toFun 𝔖 (f * g) = toFun 𝔖 f * toFun 𝔖 g := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.toFun_mul
null
UniformOnFun.ofFun_mul [Mul β] (f g : α → β) : ofFun 𝔖 (f * g) = ofFun 𝔖 f * ofFun 𝔖 g := rfl @[to_additive] instance [Inv β] : Inv (α →ᵤ β) := Pi.instInv @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.ofFun_mul
null
UniformFun.toFun_inv [Inv β] (f : α →ᵤ β) : toFun (f⁻¹) = (toFun f)⁻¹ := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.toFun_inv
null
UniformFun.ofFun_inv [Inv β] (f : α → β) : ofFun (f⁻¹) = (ofFun f)⁻¹ := rfl @[to_additive] instance [Inv β] : Inv (α →ᵤ[𝔖] β) := Pi.instInv @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.ofFun_inv
null
UniformOnFun.toFun_inv [Inv β] (f : α →ᵤ[𝔖] β) : toFun 𝔖 (f⁻¹) = (toFun 𝔖 f)⁻¹ := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.toFun_inv
null
UniformOnFun.ofFun_inv [Inv β] (f : α → β) : ofFun 𝔖 (f⁻¹) = (ofFun 𝔖 f)⁻¹ := rfl @[to_additive] instance [Div β] : Div (α →ᵤ β) := Pi.instDiv @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.ofFun_inv
null
UniformFun.toFun_div [Div β] (f g : α →ᵤ β) : toFun (f / g) = toFun f / toFun g := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.toFun_div
null
UniformFun.ofFun_div [Div β] (f g : α → β) : ofFun (f / g) = ofFun f / ofFun g := rfl @[to_additive] instance [Div β] : Div (α →ᵤ[𝔖] β) := Pi.instDiv @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.ofFun_div
null
UniformOnFun.toFun_div [Div β] (f g : α →ᵤ[𝔖] β) : toFun 𝔖 (f / g) = toFun 𝔖 f / toFun 𝔖 g := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.toFun_div
null
UniformOnFun.ofFun_div [Div β] (f g : α → β) : ofFun 𝔖 (f / g) = ofFun 𝔖 f / ofFun 𝔖 g := rfl @[to_additive]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.ofFun_div
null
@[simp] UniformFun.toFun_smul {M : Type*} [SMul M β] (c : M) (f : α →ᵤ β) : toFun (c • f) = c • toFun f := rfl @[simp]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.toFun_smul
null
UniformFun.ofFun_smul {M : Type*} [SMul M β] (c : M) (f : α → β) : ofFun (c • f) = c • ofFun f := rfl
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.ofFun_smul
null
@[simp] UniformOnFun.toFun_smul {M : Type*} [SMul M β] (c : M) (f : α →ᵤ[𝔖] β) : toFun 𝔖 (c • f) = c • toFun 𝔖 f := rfl @[simp]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.toFun_smul
null
UniformOnFun.ofFun_smul {M : Type*} [SMul M β] (c : M) (f : α → β) : ofFun 𝔖 (c • f) = c • ofFun 𝔖 f := rfl
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.ofFun_smul
null
@[to_additive] protected UniformFun.hasBasis_nhds_one_of_basis {p : ι → Prop} {b : ι → Set G} (h : (𝓝 1 : Filter G).HasBasis p b) : (𝓝 1 : Filter (α →ᵤ G)).HasBasis p fun i => { f : α →ᵤ G | ∀ x, toFun f x ∈ b i } := by convert UniformFun.hasBasis_nhds_of_basis α _ (1 : α →ᵤ G) h.uniformity_of_nhds_one simp @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.hasBasis_nhds_one_of_basis
null
protected UniformFun.hasBasis_nhds_one : (𝓝 1 : Filter (α →ᵤ G)).HasBasis (fun V : Set G => V ∈ (𝓝 1 : Filter G)) fun V => { f : α → G | ∀ x, f x ∈ V } := UniformFun.hasBasis_nhds_one_of_basis (basis_sets _)
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformFun.hasBasis_nhds_one
null
@[to_additive] protected UniformOnFun.hasBasis_nhds_one_of_basis (𝔖 : Set <| Set α) (h𝔖₁ : 𝔖.Nonempty) (h𝔖₂ : DirectedOn (· ⊆ ·) 𝔖) {p : ι → Prop} {b : ι → Set G} (h : (𝓝 1 : Filter G).HasBasis p b) : (𝓝 1 : Filter (α →ᵤ[𝔖] G)).HasBasis (fun Si : Set α × ι => Si.1 ∈ 𝔖 ∧ p Si.2) fun Si => { f : α →ᵤ[𝔖] G | ∀ x ∈ Si.1, toFun 𝔖 f x ∈ b Si.2 } := by convert UniformOnFun.hasBasis_nhds_of_basis α _ 𝔖 (1 : α →ᵤ[𝔖] G) h𝔖₁ h𝔖₂ <| h.uniformity_of_nhds_one_swapped simp [UniformOnFun.gen] @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.hasBasis_nhds_one_of_basis
null
protected UniformOnFun.hasBasis_nhds_one (𝔖 : Set <| Set α) (h𝔖₁ : 𝔖.Nonempty) (h𝔖₂ : DirectedOn (· ⊆ ·) 𝔖) : (𝓝 1 : Filter (α →ᵤ[𝔖] G)).HasBasis (fun SV : Set α × Set G => SV.1 ∈ 𝔖 ∧ SV.2 ∈ (𝓝 1 : Filter G)) fun SV => { f : α →ᵤ[𝔖] G | ∀ x ∈ SV.1, f x ∈ SV.2 } := UniformOnFun.hasBasis_nhds_one_of_basis 𝔖 h𝔖₁ h𝔖₂ (basis_sets _) @[to_additive (attr := simp)]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.hasBasis_nhds_one
null
UniformOnFun.ofFun_prod {β : Type*} [CommMonoid β] {f : ι → α → β} (I : Finset ι) : ofFun 𝔖 (∏ i ∈ I, f i) = ∏ i ∈ I, ofFun 𝔖 (f i) := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.ofFun_prod
null
UniformOnFun.toFun_prod {β : Type*} [CommMonoid β] {f : ι → α → β} (I : Finset ι) : toFun 𝔖 (∏ i ∈ I, f i) = ∏ i ∈ I, toFun 𝔖 (f i) := rfl @[to_additive (attr := simp)]
lemma
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Algebra.Module.Pi", "Mathlib.Topology.UniformSpace.UniformConvergenceTopology" ]
Mathlib/Topology/Algebra/UniformConvergence.lean
UniformOnFun.toFun_prod
null