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self_comp_symm (e : M ≃ₜ* N) : e ∘ e.symm = id := funext e.apply_symm_apply @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
self_comp_symm
null
apply_eq_iff_symm_apply (e : M ≃ₜ* N) {x : M} {y : N} : e x = y ↔ x = e.symm y := e.toEquiv.apply_eq_iff_eq_symm_apply @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
apply_eq_iff_symm_apply
null
symm_apply_eq (e : M ≃ₜ* N) {x y} : e.symm x = y ↔ x = e y := e.toEquiv.symm_apply_eq @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
symm_apply_eq
null
eq_symm_apply (e : M ≃ₜ* N) {x y} : y = e.symm x ↔ e y = x := e.toEquiv.eq_symm_apply @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
eq_symm_apply
null
eq_comp_symm {α : Type*} (e : M ≃ₜ* N) (f : N → α) (g : M → α) : f = g ∘ e.symm ↔ f ∘ e = g := e.toEquiv.eq_comp_symm f g @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
eq_comp_symm
null
comp_symm_eq {α : Type*} (e : M ≃ₜ* N) (f : N → α) (g : M → α) : g ∘ e.symm = f ↔ g = f ∘ e := e.toEquiv.comp_symm_eq f g @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
comp_symm_eq
null
eq_symm_comp {α : Type*} (e : M ≃ₜ* N) (f : α → M) (g : α → N) : f = e.symm ∘ g ↔ e ∘ f = g := e.toEquiv.eq_symm_comp f g @[to_additive]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
eq_symm_comp
null
symm_comp_eq {α : Type*} (e : M ≃ₜ* N) (f : α → M) (g : α → N) : e.symm ∘ g = f ↔ g = e ∘ f := e.toEquiv.symm_comp_eq f g
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
symm_comp_eq
null
@[to_additive /-- The composition of two ContinuousAddEquiv. -/] trans (cme1 : M ≃ₜ* N) (cme2 : N ≃ₜ* L) : M ≃ₜ* L where __ := cme1.toMulEquiv.trans cme2.toMulEquiv continuous_toFun := by convert Continuous.comp cme2.continuous_toFun cme1.continuous_toFun continuous_invFun := by convert Continuous.comp cme1.continuous_invFun cme2.continuous_invFun @[to_additive (attr := simp)]
def
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
trans
The composition of two ContinuousMulEquiv.
coe_trans (e₁ : M ≃ₜ* N) (e₂ : N ≃ₜ* L) : ↑(e₁.trans e₂) = e₂ ∘ e₁ := rfl @[to_additive (attr := simp)]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
coe_trans
null
trans_apply (e₁ : M ≃ₜ* N) (e₂ : N ≃ₜ* L) (m : M) : e₁.trans e₂ m = e₂ (e₁ m) := rfl @[to_additive (attr := simp)]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
trans_apply
null
symm_trans_apply (e₁ : M ≃ₜ* N) (e₂ : N ≃ₜ* L) (l : L) : (e₁.trans e₂).symm l = e₁.symm (e₂.symm l) := rfl @[to_additive (attr := simp)]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
symm_trans_apply
null
symm_trans_self (e : M ≃ₜ* N) : e.symm.trans e = refl N := DFunLike.ext _ _ e.apply_symm_apply @[to_additive (attr := simp)]
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
symm_trans_self
null
self_trans_symm (e : M ≃ₜ* N) : e.trans e.symm = refl M := DFunLike.ext _ _ e.symm_apply_apply
theorem
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
self_trans_symm
null
@[to_additive /-- The `AddEquiv` between two `AddMonoid`s with a unique element. -/] ofUnique {M N} [Unique M] [Unique N] [Mul M] [Mul N] [TopologicalSpace M] [TopologicalSpace N] : M ≃ₜ* N where __ := MulEquiv.ofUnique continuous_toFun := by continuity continuous_invFun := by continuity
def
Topology
[ "Mathlib.Algebra.Group.Equiv.Basic", "Mathlib.Topology.Algebra.Group.Defs" ]
Mathlib/Topology/Algebra/ContinuousMonoidHom.lean
ofUnique
The `MulEquiv` between two monoids with a unique element.
@[to_additive] equicontinuous_of_equicontinuousAt_one {ι G M hom : Type*} [TopologicalSpace G] [UniformSpace M] [Group G] [Group M] [IsTopologicalGroup G] [IsUniformGroup M] [FunLike hom G M] [MonoidHomClass hom G M] (F : ι → hom) (hf : EquicontinuousAt ((↑) ∘ F) (1 : G)) : Equicontinuous ((↑) ∘ F) := by rw [equicontinuous_iff_continuous] rw [equicontinuousAt_iff_continuousAt] at hf let φ : G →* (ι →ᵤ M) := { toFun := swap ((↑) ∘ F) map_one' := by dsimp [UniformFun]; ext; exact map_one _ map_mul' := fun a b => by dsimp [UniformFun]; ext; exact map_mul _ _ _ } exact continuous_of_continuousAt_one φ hf @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformConvergence", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/Algebra/Equicontinuity.lean
equicontinuous_of_equicontinuousAt_one
null
uniformEquicontinuous_of_equicontinuousAt_one {ι G M hom : Type*} [UniformSpace G] [UniformSpace M] [Group G] [Group M] [IsUniformGroup G] [IsUniformGroup M] [FunLike hom G M] [MonoidHomClass hom G M] (F : ι → hom) (hf : EquicontinuousAt ((↑) ∘ F) (1 : G)) : UniformEquicontinuous ((↑) ∘ F) := by rw [uniformEquicontinuous_iff_uniformContinuous] rw [equicontinuousAt_iff_continuousAt] at hf let φ : G →* (ι →ᵤ M) := { toFun := swap ((↑) ∘ F) map_one' := by dsimp [UniformFun]; ext; exact map_one _ map_mul' := fun a b => by dsimp [UniformFun]; ext; exact map_mul _ _ _ } exact uniformContinuous_of_continuousAt_one φ hf
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformConvergence", "Mathlib.Topology.UniformSpace.Equicontinuity" ]
Mathlib/Topology/Algebra/Equicontinuity.lean
uniformEquicontinuous_of_equicontinuousAt_one
null
Filter.tendsto_cocompact_mul_left₀ [ContinuousMul K] {a : K} (ha : a ≠ 0) : Filter.Tendsto (fun x : K => a * x) (Filter.cocompact K) (Filter.cocompact K) := Filter.tendsto_cocompact_mul_left (inv_mul_cancel₀ ha)
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
Filter.tendsto_cocompact_mul_left₀
Left-multiplication by a nonzero element of a topological division ring is proper, i.e., inverse images of compact sets are compact.
Filter.tendsto_cocompact_mul_right₀ [ContinuousMul K] {a : K} (ha : a ≠ 0) : Filter.Tendsto (fun x : K => x * a) (Filter.cocompact K) (Filter.cocompact K) := Filter.tendsto_cocompact_mul_right (mul_inv_cancel₀ ha)
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
Filter.tendsto_cocompact_mul_right₀
Right-multiplication by a nonzero element of a topological division ring is proper, i.e., inverse images of compact sets are compact.
DivisionRing.finite_of_compactSpace_of_t2Space {K} [DivisionRing K] [TopologicalSpace K] [IsTopologicalRing K] [CompactSpace K] [T2Space K] : Finite K := by suffices DiscreteTopology K by exact finite_of_compact_of_discrete rw [discreteTopology_iff_isOpen_singleton_zero] exact GroupWithZero.isOpen_singleton_zero variable (K)
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
DivisionRing.finite_of_compactSpace_of_t2Space
Compact Hausdorff topological fields are finite. This is not an instance, as it would apply to every `Finite` goal, causing slowly failing typeclass search in some cases.
IsTopologicalDivisionRing : Prop extends IsTopologicalRing K, ContinuousInv₀ K @[deprecated (since := "2025-03-25")] alias TopologicalDivisionRing := IsTopologicalDivisionRing
class
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
IsTopologicalDivisionRing
A topological division ring is a division ring with a topology where all operations are continuous, including inversion.
Subfield.topologicalClosure (K : Subfield α) : Subfield α := { K.toSubring.topologicalClosure with carrier := _root_.closure (K : Set α) inv_mem' := fun x hx => by rcases eq_or_ne x 0 with (rfl | h) · rwa [inv_zero] · rw [← inv_coe_set, ← Set.image_inv_eq_inv] exact mem_closure_image (continuousAt_inv₀ h) hx }
def
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
Subfield.topologicalClosure
The (topological-space) closure of a subfield of a topological field is itself a subfield.
Subfield.le_topologicalClosure (s : Subfield α) : s ≤ s.topologicalClosure := _root_.subset_closure
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
Subfield.le_topologicalClosure
null
Subfield.isClosed_topologicalClosure (s : Subfield α) : IsClosed (s.topologicalClosure : Set α) := isClosed_closure
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
Subfield.isClosed_topologicalClosure
null
Subfield.topologicalClosure_minimal (s : Subfield α) {t : Subfield α} (h : s ≤ t) (ht : IsClosed (t : Set α)) : s.topologicalClosure ≤ t := closure_minimal h ht
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
Subfield.topologicalClosure_minimal
null
@[simps] affineHomeomorph (a b : 𝕜) (h : a ≠ 0) : 𝕜 ≃ₜ 𝕜 where toFun x := a * x + b invFun y := (y - b) / a left_inv x := by simp only [add_sub_cancel_right] exact mul_div_cancel_left₀ x h right_inv y := by simp [mul_div_cancel₀ _ h]
def
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
affineHomeomorph
The map `fun x => a * x + b`, as a homeomorphism from `𝕜` (a topological field) to itself, when `a ≠ 0`.
affineHomeomorph_image_Icc {𝕜 : Type*} [Field 𝕜] [LinearOrder 𝕜] [IsStrictOrderedRing 𝕜] [TopologicalSpace 𝕜] [IsTopologicalRing 𝕜] (a b c d : 𝕜) (h : 0 < a) : affineHomeomorph a b h.ne' '' Set.Icc c d = Set.Icc (a * c + b) (a * d + b) := by simp [h]
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
affineHomeomorph_image_Icc
null
affineHomeomorph_image_Ico {𝕜 : Type*} [Field 𝕜] [LinearOrder 𝕜] [IsStrictOrderedRing 𝕜] [TopologicalSpace 𝕜] [IsTopologicalRing 𝕜] (a b c d : 𝕜) (h : 0 < a) : affineHomeomorph a b h.ne' '' Set.Ico c d = Set.Ico (a * c + b) (a * d + b) := by simp [h]
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
affineHomeomorph_image_Ico
null
affineHomeomorph_image_Ioc {𝕜 : Type*} [Field 𝕜] [LinearOrder 𝕜] [IsStrictOrderedRing 𝕜] [TopologicalSpace 𝕜] [IsTopologicalRing 𝕜] (a b c d : 𝕜) (h : 0 < a) : affineHomeomorph a b h.ne' '' Set.Ioc c d = Set.Ioc (a * c + b) (a * d + b) := by simp [h]
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
affineHomeomorph_image_Ioc
null
affineHomeomorph_image_Ioo {𝕜 : Type*} [Field 𝕜] [LinearOrder 𝕜] [IsStrictOrderedRing 𝕜] [TopologicalSpace 𝕜] [IsTopologicalRing 𝕜] (a b c d : 𝕜) (h : 0 < a) : affineHomeomorph a b h.ne' '' Set.Ioo c d = Set.Ioo (a * c + b) (a * d + b) := by simp [h]
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
affineHomeomorph_image_Ioo
null
IsLocalMin.inv {f : α → β} {a : α} (h1 : IsLocalMin f a) (h2 : ∀ᶠ z in 𝓝 a, 0 < f z) : IsLocalMax f⁻¹ a := by filter_upwards [h1, h2] with z h3 h4 using(inv_le_inv₀ h4 h2.self_of_nhds).mpr h3
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
IsLocalMin.inv
null
IsPreconnected.eq_one_or_eq_neg_one_of_sq_eq [Ring 𝕜] [NoZeroDivisors 𝕜] (hS : IsPreconnected S) (hf : ContinuousOn f S) (hsq : EqOn (f ^ 2) 1 S) : EqOn f 1 S ∨ EqOn f (-1) S := by have : DiscreteTopology ({1, -1} : Set 𝕜) := Finite.instDiscreteTopology have hmaps : MapsTo f S {1, -1} := by simpa only [EqOn, Pi.one_apply, Pi.pow_apply, sq_eq_one_iff] using hsq simpa using hS.eqOn_const_of_mapsTo hf hmaps
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
IsPreconnected.eq_one_or_eq_neg_one_of_sq_eq
If `f` is a function `α → 𝕜` which is continuous on a preconnected set `S`, and `f ^ 2 = 1` on `S`, then either `f = 1` on `S`, or `f = -1` on `S`.
IsPreconnected.eq_or_eq_neg_of_sq_eq [Field 𝕜] [ContinuousInv₀ 𝕜] [ContinuousMul 𝕜] (hS : IsPreconnected S) (hf : ContinuousOn f S) (hg : ContinuousOn g S) (hsq : EqOn (f ^ 2) (g ^ 2) S) (hg_ne : ∀ {x : α}, x ∈ S → g x ≠ 0) : EqOn f g S ∨ EqOn f (-g) S := by have hsq : EqOn ((f / g) ^ 2) 1 S := fun x hx => by simpa [div_eq_one_iff_eq (pow_ne_zero _ (hg_ne hx)), div_pow] using hsq hx simpa +contextual [EqOn, div_eq_iff (hg_ne _)] using hS.eq_one_or_eq_neg_one_of_sq_eq (hf.div hg fun z => hg_ne) hsq
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
IsPreconnected.eq_or_eq_neg_of_sq_eq
If `f, g` are functions `α → 𝕜`, both continuous on a preconnected set `S`, with `f ^ 2 = g ^ 2` on `S`, and `g z ≠ 0` all `z ∈ S`, then either `f = g` or `f = -g` on `S`.
IsPreconnected.eq_of_sq_eq [Field 𝕜] [ContinuousInv₀ 𝕜] [ContinuousMul 𝕜] (hS : IsPreconnected S) (hf : ContinuousOn f S) (hg : ContinuousOn g S) (hsq : EqOn (f ^ 2) (g ^ 2) S) (hg_ne : ∀ {x : α}, x ∈ S → g x ≠ 0) {y : α} (hy : y ∈ S) (hy' : f y = g y) : EqOn f g S := fun x hx => by rcases hS.eq_or_eq_neg_of_sq_eq hf hg @hsq @hg_ne with (h | h) · exact h hx · rw [h _, Pi.neg_apply, neg_eq_iff_add_eq_zero, ← two_mul, mul_eq_zero, (iff_of_eq (iff_false _)).2 (hg_ne _)] at hy' ⊢ <;> assumption
theorem
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
IsPreconnected.eq_of_sq_eq
If `f, g` are functions `α → 𝕜`, both continuous on a preconnected set `S`, with `f ^ 2 = g ^ 2` on `S`, and `g z ≠ 0` all `z ∈ S`, then as soon as `f = g` holds at one point of `S` it holds for all points.
Subfield.continuousSMul (M : Subfield F) : ContinuousSMul M X := Subring.continuousSMul M.toSubring X
instance
Topology
[ "Mathlib.Algebra.Field.Subfield.Defs", "Mathlib.Algebra.GroupWithZero.Divisibility", "Mathlib.Algebra.Order.Group.Pointwise.Interval", "Mathlib.Topology.Algebra.GroupWithZero", "Mathlib.Topology.Algebra.Ring.Basic", "Mathlib.Topology.Order.LocalExtr" ]
Mathlib/Topology/Algebra/Field.lean
Subfield.continuousSMul
null
GroupFilterBasis (G : Type u) [Group G] extends FilterBasis G where one' : ∀ {U}, U ∈ sets → (1 : G) ∈ U mul' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V * V ⊆ U inv' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ * x * x₀⁻¹) ⁻¹' U
class
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
GroupFilterBasis
A `GroupFilterBasis` on a group is a `FilterBasis` satisfying some additional axioms. Example : if `G` is a topological group then the neighbourhoods of the identity are a `GroupFilterBasis`. Conversely given a `GroupFilterBasis` one can define a topology compatible with the group structure on `G`.
AddGroupFilterBasis (A : Type u) [AddGroup A] extends FilterBasis A where zero' : ∀ {U}, U ∈ sets → (0 : A) ∈ U add' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V + V ⊆ U neg' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ -x) ⁻¹' U conj' : ∀ x₀, ∀ {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ + x + -x₀) ⁻¹' U attribute [to_additive] GroupFilterBasis
class
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
AddGroupFilterBasis
An `AddGroupFilterBasis` on an additive group is a `FilterBasis` satisfying some additional axioms. Example : if `G` is a topological group then the neighbourhoods of the identity are an `AddGroupFilterBasis`. Conversely given an `AddGroupFilterBasis` one can define a topology compatible with the group structure on `G`.
@[to_additive /-- `AddGroupFilterBasis` constructor in the additive commutative group case. -/] groupFilterBasisOfComm {G : Type*} [CommGroup G] (sets : Set (Set G)) (nonempty : sets.Nonempty) (inter_sets : ∀ x y, x ∈ sets → y ∈ sets → ∃ z ∈ sets, z ⊆ x ∩ y) (one : ∀ U ∈ sets, (1 : G) ∈ U) (mul : ∀ U ∈ sets, ∃ V ∈ sets, V * V ⊆ U) (inv : ∀ U ∈ sets, ∃ V ∈ sets, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U) : GroupFilterBasis G := { sets := sets nonempty := nonempty inter_sets := inter_sets _ _ one' := one _ mul' := mul _ inv' := inv _ conj' := fun x U U_in ↦ ⟨U, U_in, by simp only [mul_inv_cancel_comm, preimage_id']; rfl⟩ }
def
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
groupFilterBasisOfComm
`GroupFilterBasis` constructor in the commutative group case.
@[to_additive] one {U : Set G} : U ∈ B → (1 : G) ∈ U := GroupFilterBasis.one' @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
one
null
mul {U : Set G} : U ∈ B → ∃ V ∈ B, V * V ⊆ U := GroupFilterBasis.mul' @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
mul
null
inv {U : Set G} : U ∈ B → ∃ V ∈ B, V ⊆ (fun x ↦ x⁻¹) ⁻¹' U := GroupFilterBasis.inv' @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
inv
null
conj : ∀ x₀, ∀ {U}, U ∈ B → ∃ V ∈ B, V ⊆ (fun x ↦ x₀ * x * x₀⁻¹) ⁻¹' U := GroupFilterBasis.conj'
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
conj
null
@[to_additive /-- The neighborhood function of an `AddGroupFilterBasis`. -/] N (B : GroupFilterBasis G) : G → Filter G := fun x ↦ map (fun y ↦ x * y) B.toFilterBasis.filter @[to_additive (attr := simp)]
def
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
N
The trivial group filter basis consists of `{1}` only. The associated topology is discrete. -/ @[to_additive /-- The trivial additive group filter basis consists of `{0}` only. The associated topology is discrete. -/] instance : Inhabited (GroupFilterBasis G) where default := { sets := {{1}} nonempty := singleton_nonempty _ inter_sets := by simp one' := by simp mul' := by simp inv' := by simp conj' := by simp } @[to_additive] theorem subset_mul_self (B : GroupFilterBasis G) {U : Set G} (h : U ∈ B) : U ⊆ U * U := fun x x_in ↦ ⟨1, one h, x, x_in, one_mul x⟩ /-- The neighborhood function of a `GroupFilterBasis`.
N_one (B : GroupFilterBasis G) : B.N 1 = B.toFilterBasis.filter := by simp only [N, one_mul, map_id'] @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
N_one
null
protected hasBasis (B : GroupFilterBasis G) (x : G) : HasBasis (B.N x) (fun V : Set G ↦ V ∈ B) fun V ↦ (fun y ↦ x * y) '' V := HasBasis.map (fun y ↦ x * y) toFilterBasis.hasBasis
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
hasBasis
null
@[to_additive /-- The topological space structure coming from an additive group filter basis. -/] topology (B : GroupFilterBasis G) : TopologicalSpace G := TopologicalSpace.mkOfNhds B.N @[to_additive]
def
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
topology
The topological space structure coming from a group filter basis.
nhds_eq (B : GroupFilterBasis G) {x₀ : G} : @nhds G B.topology x₀ = B.N x₀ := by apply TopologicalSpace.nhds_mkOfNhds_of_hasBasis (fun x ↦ (FilterBasis.hasBasis _).map _) · intro a U U_in exact ⟨1, B.one U_in, mul_one a⟩ · intro a U U_in rcases GroupFilterBasis.mul U_in with ⟨V, V_in, hVU⟩ filter_upwards [image_mem_map (B.mem_filter_of_mem V_in)] rintro _ ⟨x, hx, rfl⟩ calc (a * x) • V ∈ (a * x) • B.filter := smul_set_mem_smul_filter <| B.mem_filter_of_mem V_in _ = a • x • V := smul_smul .. |>.symm _ ⊆ a • (V * V) := smul_set_mono <| smul_set_subset_smul hx _ ⊆ a • U := smul_set_mono hVU @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
nhds_eq
null
nhds_one_eq (B : GroupFilterBasis G) : @nhds G B.topology (1 : G) = B.toFilterBasis.filter := by rw [B.nhds_eq] simp only [N, one_mul] exact map_id @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
nhds_one_eq
null
nhds_hasBasis (B : GroupFilterBasis G) (x₀ : G) : HasBasis (@nhds G B.topology x₀) (fun V : Set G ↦ V ∈ B) fun V ↦ (fun y ↦ x₀ * y) '' V := by rw [B.nhds_eq] apply B.hasBasis @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
nhds_hasBasis
null
nhds_one_hasBasis (B : GroupFilterBasis G) : HasBasis (@nhds G B.topology 1) (fun V : Set G ↦ V ∈ B) id := by rw [B.nhds_one_eq] exact B.toFilterBasis.hasBasis @[to_additive]
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
nhds_one_hasBasis
null
mem_nhds_one (B : GroupFilterBasis G) {U : Set G} (hU : U ∈ B) : U ∈ @nhds G B.topology 1 := by rw [B.nhds_one_hasBasis.mem_iff] exact ⟨U, hU, rfl.subset⟩
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
mem_nhds_one
null
RingFilterBasis (R : Type u) [Ring R] extends AddGroupFilterBasis R where mul' : ∀ {U}, U ∈ sets → ∃ V ∈ sets, V * V ⊆ U mul_left' : ∀ (x₀ : R) {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ * x) ⁻¹' U mul_right' : ∀ (x₀ : R) {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x * x₀) ⁻¹' U
class
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
RingFilterBasis
If a group is endowed with a topological structure coming from a group filter basis then, it's a topological group. -/ @[to_additive /-- If an additive group is endowed with a topological structure coming from an additive group filter basis, then it's an additive topological group. -/] instance (priority := 100) isTopologicalGroup (B : GroupFilterBasis G) : @IsTopologicalGroup G B.topology _ := by letI := B.topology have basis := B.nhds_one_hasBasis have basis' := basis.prod basis refine IsTopologicalGroup.of_nhds_one ?_ ?_ ?_ ?_ · rw [basis'.tendsto_iff basis] suffices ∀ U ∈ B, ∃ V W, (V ∈ B ∧ W ∈ B) ∧ ∀ a b, a ∈ V → b ∈ W → a * b ∈ U by simpa intro U U_in rcases mul U_in with ⟨V, V_in, hV⟩ refine ⟨V, V, ⟨V_in, V_in⟩, ?_⟩ intro a b a_in b_in exact hV <| mul_mem_mul a_in b_in · rw [basis.tendsto_iff basis] intro U U_in simpa using inv U_in · intro x₀ rw [nhds_eq, nhds_one_eq] rfl · intro x₀ rw [basis.tendsto_iff basis] intro U U_in exact conj x₀ U_in end GroupFilterBasis /-- A `RingFilterBasis` on a ring is a `FilterBasis` satisfying some additional axioms. Example : if `R` is a topological ring then the neighbourhoods of the identity are a `RingFilterBasis`. Conversely given a `RingFilterBasis` on a ring `R`, one can define a topology on `R` which is compatible with the ring structure.
mul {U : Set R} (hU : U ∈ B) : ∃ V ∈ B, V * V ⊆ U := mul' hU
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
mul
null
mul_left (x₀ : R) {U : Set R} (hU : U ∈ B) : ∃ V ∈ B, V ⊆ (fun x ↦ x₀ * x) ⁻¹' U := mul_left' x₀ hU
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
mul_left
null
mul_right (x₀ : R) {U : Set R} (hU : U ∈ B) : ∃ V ∈ B, V ⊆ (fun x ↦ x * x₀) ⁻¹' U := mul_right' x₀ hU
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
mul_right
null
topology : TopologicalSpace R := B.toAddGroupFilterBasis.topology
def
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
topology
The topology associated to a ring filter basis. It has the given basis as a basis of neighborhoods of zero.
ModuleFilterBasis (R M : Type*) [CommRing R] [TopologicalSpace R] [AddCommGroup M] [Module R M] extends AddGroupFilterBasis M where smul' : ∀ {U}, U ∈ sets → ∃ V ∈ 𝓝 (0 : R), ∃ W ∈ sets, V • W ⊆ U smul_left' : ∀ (x₀ : R) {U}, U ∈ sets → ∃ V ∈ sets, V ⊆ (fun x ↦ x₀ • x) ⁻¹' U smul_right' : ∀ (m₀ : M) {U}, U ∈ sets → ∀ᶠ x in 𝓝 (0 : R), x • m₀ ∈ U
structure
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
ModuleFilterBasis
If a ring is endowed with a topological structure coming from a ring filter basis then it's a topological ring. -/ instance (priority := 100) isTopologicalRing {R : Type u} [Ring R] (B : RingFilterBasis R) : @IsTopologicalRing R B.topology _ := by let B' := B.toAddGroupFilterBasis letI := B'.topology have basis := B'.nhds_zero_hasBasis have basis' := basis.prod basis haveI := B'.isTopologicalAddGroup apply IsTopologicalRing.of_addGroup_of_nhds_zero · rw [basis'.tendsto_iff basis] suffices ∀ U ∈ B', ∃ V W, (V ∈ B' ∧ W ∈ B') ∧ ∀ a b, a ∈ V → b ∈ W → a * b ∈ U by simpa intro U U_in rcases B.mul U_in with ⟨V, V_in, hV⟩ refine ⟨V, V, ⟨V_in, V_in⟩, ?_⟩ intro a b a_in b_in exact hV <| mul_mem_mul a_in b_in · intro x₀ rw [basis.tendsto_iff basis] intro U simpa using B.mul_left x₀ · intro x₀ rw [basis.tendsto_iff basis] intro U simpa using B.mul_right x₀ end RingFilterBasis /-- A `ModuleFilterBasis` on a module is a `FilterBasis` satisfying some additional axioms. Example : if `M` is a topological module then the neighbourhoods of zero are a `ModuleFilterBasis`. Conversely given a `ModuleFilterBasis` one can define a topology compatible with the module structure on `M`.
GroupFilterBasis.hasMem : Membership (Set M) (ModuleFilterBasis R M) := ⟨fun B s ↦ s ∈ B.sets⟩
instance
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
GroupFilterBasis.hasMem
null
smul {U : Set M} (hU : U ∈ B) : ∃ V ∈ 𝓝 (0 : R), ∃ W ∈ B, V • W ⊆ U := B.smul' hU
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
smul
null
smul_left (x₀ : R) {U : Set M} (hU : U ∈ B) : ∃ V ∈ B, V ⊆ (fun x ↦ x₀ • x) ⁻¹' U := B.smul_left' x₀ hU
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
smul_left
null
smul_right (m₀ : M) {U : Set M} (hU : U ∈ B) : ∀ᶠ x in 𝓝 (0 : R), x • m₀ ∈ U := B.smul_right' m₀ hU
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
smul_right
null
topology : TopologicalSpace M := B.toAddGroupFilterBasis.topology
def
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
topology
If `R` is discrete then the trivial additive group filter basis on any `R`-module is a module filter basis. -/ instance [DiscreteTopology R] : Inhabited (ModuleFilterBasis R M) := ⟨{ show AddGroupFilterBasis M from default with smul' := by rintro U (rfl : U ∈ {{(0 : M)}}) use univ, univ_mem, {0}, rfl rintro a ⟨x, -, m, rfl, rfl⟩ simp only [smul_zero, mem_singleton_iff] smul_left' := by rintro x₀ U (h : U ∈ {{(0 : M)}}) rw [mem_singleton_iff] at h use {0}, rfl simp [h] smul_right' := by rintro m₀ U (h : U ∈ (0 : Set (Set M))) rw [Set.mem_zero] at h simp [h, nhds_discrete] }⟩ /-- The topology associated to a module filter basis on a module over a topological ring. It has the given basis as a basis of neighborhoods of zero.
topology' {R M : Type*} [CommRing R] {_ : TopologicalSpace R} [AddCommGroup M] [Module R M] (B : ModuleFilterBasis R M) : TopologicalSpace M := B.toAddGroupFilterBasis.topology
def
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
topology'
The topology associated to a module filter basis on a module over a topological ring. It has the given basis as a basis of neighborhoods of zero. This version gets the ring topology by unification instead of type class inference.
_root_.ContinuousSMul.of_basis_zero {ι : Type*} [IsTopologicalRing R] [TopologicalSpace M] [IsTopologicalAddGroup M] {p : ι → Prop} {b : ι → Set M} (h : HasBasis (𝓝 0) p b) (hsmul : ∀ {i}, p i → ∃ V ∈ 𝓝 (0 : R), ∃ j, p j ∧ V • b j ⊆ b i) (hsmul_left : ∀ (x₀ : R) {i}, p i → ∃ j, p j ∧ MapsTo (x₀ • ·) (b j) (b i)) (hsmul_right : ∀ (m₀ : M) {i}, p i → ∀ᶠ x in 𝓝 (0 : R), x • m₀ ∈ b i) : ContinuousSMul R M := by apply ContinuousSMul.of_nhds_zero · rw [h.tendsto_right_iff] intro i hi rcases hsmul hi with ⟨V, V_in, j, hj, hVj⟩ apply mem_of_superset (prod_mem_prod V_in <| h.mem_of_mem hj) rintro ⟨v, w⟩ ⟨v_in : v ∈ V, w_in : w ∈ b j⟩ exact hVj (Set.smul_mem_smul v_in w_in) · intro m₀ rw [h.tendsto_right_iff] intro i hi exact hsmul_right m₀ hi · intro x₀ rw [h.tendsto_right_iff] intro i hi rcases hsmul_left x₀ hi with ⟨j, hj, hji⟩ exact mem_of_superset (h.mem_of_mem hj) hji
theorem
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
_root_.ContinuousSMul.of_basis_zero
A topological additive group with a basis of `𝓝 0` satisfying the axioms of `ModuleFilterBasis` is a topological module. This lemma is mathematically useless because one could obtain such a result by applying `ModuleFilterBasis.continuousSMul` and use the fact that group topologies are characterized by their neighborhoods of 0 to obtain the `ContinuousSMul` on the pre-existing topology. But it turns out it's just easier to get it as a byproduct of the proof, so this is just a free quality-of-life improvement.
ofBases {R M : Type*} [CommRing R] [AddCommGroup M] [Module R M] (BR : RingFilterBasis R) (BM : AddGroupFilterBasis M) (smul : ∀ {U}, U ∈ BM → ∃ V ∈ BR, ∃ W ∈ BM, V • W ⊆ U) (smul_left : ∀ (x₀ : R) {U}, U ∈ BM → ∃ V ∈ BM, V ⊆ (fun x ↦ x₀ • x) ⁻¹' U) (smul_right : ∀ (m₀ : M) {U}, U ∈ BM → ∃ V ∈ BR, V ⊆ (fun x ↦ x • m₀) ⁻¹' U) : @ModuleFilterBasis R M _ BR.topology _ _ := let _ := BR.topology { BM with smul' := by intro U U_in rcases smul U_in with ⟨V, V_in, W, W_in, H⟩ exact ⟨V, BR.toAddGroupFilterBasis.mem_nhds_zero V_in, W, W_in, H⟩ smul_left' := smul_left smul_right' := by intro m₀ U U_in rcases smul_right m₀ U_in with ⟨V, V_in, H⟩ exact mem_of_superset (BR.toAddGroupFilterBasis.mem_nhds_zero V_in) H }
def
Topology
[ "Mathlib.Topology.Algebra.Module.Basic" ]
Mathlib/Topology/Algebra/FilterBasis.lean
ofBases
If a module is endowed with a topological structure coming from a module filter basis then it's a topological module. -/ instance (priority := 100) continuousSMul [IsTopologicalRing R] : @ContinuousSMul R M _ _ B.topology := by let B' := B.toAddGroupFilterBasis let _ := B'.topology have _ := B'.isTopologicalAddGroup exact ContinuousSMul.of_basis_zero B'.nhds_zero_hasBasis (fun {_} => by simpa using B.smul) (by simpa using B.smul_left) B.smul_right /-- Build a module filter basis from compatible ring and additive group filter bases.
@[norm_cast] UniformSpace.Completion.coe_zero [Zero α] : ((0 : α) : Completion α) = 0 := rfl @[simp] lemma UniformSpace.Completion.coe_eq_zero_iff [Zero α] [T0Space α] {x : α} : (x : Completion α) = 0 ↔ x = 0 := Completion.coe_inj
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
UniformSpace.Completion.coe_zero
null
@[norm_cast] coe_neg (a : α) : ((-a : α) : Completion α) = -a := (map_coe uniformContinuous_neg a).symm @[norm_cast]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
coe_neg
null
coe_sub (a b : α) : ((a - b : α) : Completion α) = a - b := (map₂_coe_coe a b Sub.sub uniformContinuous_sub).symm @[norm_cast]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
coe_sub
null
coe_add (a b : α) : ((a + b : α) : Completion α) = a + b := (map₂_coe_coe a b (· + ·) uniformContinuous_add).symm
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
coe_add
null
addGroup : AddGroup (Completion α) := { (inferInstance : SubNegMonoid <| Completion α) with neg_add_cancel := fun a ↦ Completion.induction_on a (isClosed_eq (continuous_map₂ Completion.continuous_map continuous_id) continuous_const) fun a ↦ show -(a : Completion α) + a = 0 by rw_mod_cast [neg_add_cancel] rfl }
instance
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
addGroup
null
isUniformAddGroup : IsUniformAddGroup (Completion α) := ⟨uniformContinuous_map₂ Sub.sub⟩
instance
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
isUniformAddGroup
null
@[simps] toCompl : α →+ Completion α where toFun := (↑) map_add' := coe_add map_zero' := coe_zero
def
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
toCompl
The map from a group to its completion as a group hom.
continuous_toCompl : Continuous (toCompl : α → Completion α) := continuous_coe α variable (α) in
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
continuous_toCompl
null
isDenseInducing_toCompl : IsDenseInducing (toCompl : α → Completion α) := isDenseInducing_coe
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
isDenseInducing_toCompl
null
instAddCommGroup : AddCommGroup (Completion α) := { (inferInstance : AddGroup <| Completion α) with add_comm := fun a b ↦ Completion.induction_on₂ a b (isClosed_eq (continuous_map₂ continuous_fst continuous_snd) (continuous_map₂ continuous_snd continuous_fst)) fun x y ↦ by change (x : Completion α) + ↑y = ↑y + ↑x rw [← coe_add, ← coe_add, add_comm] }
instance
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
instAddCommGroup
null
instModule [Semiring R] [Module R α] [UniformContinuousConstSMul R α] : Module R (Completion α) := { (inferInstance : DistribMulAction R <| Completion α), (inferInstance : MulActionWithZero R <| Completion α) with add_smul := fun a b ↦ ext' (continuous_const_smul _) ((continuous_const_smul _).add (continuous_const_smul _)) fun x ↦ by rw [← coe_smul, add_smul, coe_add, coe_smul, coe_smul] }
instance
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
instModule
null
AddMonoidHom.extension [CompleteSpace β] [T0Space β] (f : α →+ β) (hf : Continuous f) : Completion α →+ β := have hf : UniformContinuous f := uniformContinuous_addMonoidHom_of_continuous hf { toFun := Completion.extension f map_zero' := by rw [← coe_zero, extension_coe hf, f.map_zero] map_add' := fun a b ↦ Completion.induction_on₂ a b (isClosed_eq (continuous_extension.comp continuous_add) ((continuous_extension.comp continuous_fst).add (continuous_extension.comp continuous_snd))) fun a b ↦ show Completion.extension f _ = Completion.extension f _ + Completion.extension f _ by rw_mod_cast [extension_coe hf, extension_coe hf, extension_coe hf, f.map_add] }
def
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.extension
Extension to the completion of a continuous group hom.
AddMonoidHom.extension_coe [CompleteSpace β] [T0Space β] (f : α →+ β) (hf : Continuous f) (a : α) : f.extension hf a = f a := UniformSpace.Completion.extension_coe (uniformContinuous_addMonoidHom_of_continuous hf) a @[continuity]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.extension_coe
null
AddMonoidHom.continuous_extension [CompleteSpace β] [T0Space β] (f : α →+ β) (hf : Continuous f) : Continuous (f.extension hf) := UniformSpace.Completion.continuous_extension
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.continuous_extension
null
AddMonoidHom.completion (f : α →+ β) (hf : Continuous f) : Completion α →+ Completion β := (toCompl.comp f).extension (continuous_toCompl.comp hf) @[continuity]
def
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.completion
Completion of a continuous group hom, as a group hom.
AddMonoidHom.continuous_completion (f : α →+ β) (hf : Continuous f) : Continuous (AddMonoidHom.completion f hf : Completion α → Completion β) := continuous_map
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.continuous_completion
null
AddMonoidHom.completion_coe (f : α →+ β) (hf : Continuous f) (a : α) : AddMonoidHom.completion f hf a = f a := map_coe (uniformContinuous_addMonoidHom_of_continuous hf) a
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.completion_coe
null
AddMonoidHom.completion_zero : AddMonoidHom.completion (0 : α →+ β) continuous_const = 0 := by ext x refine Completion.induction_on x ?_ ?_ · apply isClosed_eq (AddMonoidHom.continuous_completion (0 : α →+ β) continuous_const) exact continuous_const · simp [(0 : α →+ β).completion_coe continuous_const, coe_zero]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.completion_zero
null
AddMonoidHom.completion_add {γ : Type*} [AddCommGroup γ] [UniformSpace γ] [IsUniformAddGroup γ] (f g : α →+ γ) (hf : Continuous f) (hg : Continuous g) : AddMonoidHom.completion (f + g) (hf.add hg) = AddMonoidHom.completion f hf + AddMonoidHom.completion g hg := by have hfg := hf.add hg ext x refine Completion.induction_on x ?_ ?_ · exact isClosed_eq ((f + g).continuous_completion hfg) ((f.continuous_completion hf).add (g.continuous_completion hg)) · simp [(f + g).completion_coe hfg, coe_add, f.completion_coe hf, g.completion_coe hg]
theorem
Topology
[ "Mathlib.Topology.Algebra.UniformMulAction", "Mathlib.Topology.UniformSpace.Completion", "Mathlib.Topology.Algebra.Group.Pointwise" ]
Mathlib/Topology/Algebra/GroupCompletion.lean
AddMonoidHom.completion_add
null
Filter.Tendsto.div_const {x : G₀} (hf : Tendsto f l (𝓝 x)) (y : G₀) : Tendsto (fun a => f a / y) l (𝓝 (x / y)) := by simpa only [div_eq_mul_inv] using hf.mul tendsto_const_nhds variable [TopologicalSpace α] nonrec theorem ContinuousAt.div_const {a : α} (hf : ContinuousAt f a) (y : G₀) : ContinuousAt (fun x => f x / y) a := hf.div_const y nonrec theorem ContinuousWithinAt.div_const {a} (hf : ContinuousWithinAt f s a) (y : G₀) : ContinuousWithinAt (fun x => f x / y) s a := hf.div_const _
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
Filter.Tendsto.div_const
null
ContinuousOn.div_const (hf : ContinuousOn f s) (y : G₀) : ContinuousOn (fun x => f x / y) s := by simpa only [div_eq_mul_inv] using hf.mul continuousOn_const @[continuity, fun_prop]
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
ContinuousOn.div_const
null
Continuous.div_const (hf : Continuous f) (y : G₀) : Continuous fun x => f x / y := by simpa only [div_eq_mul_inv] using hf.mul continuous_const
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
Continuous.div_const
null
ContinuousInv₀ (G₀ : Type*) [Zero G₀] [Inv G₀] [TopologicalSpace G₀] : Prop where /-- The map `fun x ↦ x⁻¹` is continuous at all nonzero points. -/ continuousAt_inv₀ : ∀ ⦃x : G₀⦄, x ≠ 0 → ContinuousAt Inv.inv x export ContinuousInv₀ (continuousAt_inv₀) @[deprecated (since := "2025-09-01")] alias HasContinuousInv₀ := ContinuousInv₀
class
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
ContinuousInv₀
A type with `0` and `Inv` such that `fun x ↦ x⁻¹` is continuous at all nonzero points. Any normed (semi)field has this property.
tendsto_inv₀ {x : G₀} (hx : x ≠ 0) : Tendsto Inv.inv (𝓝 x) (𝓝 x⁻¹) := continuousAt_inv₀ hx
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
tendsto_inv₀
null
continuousOn_inv₀ : ContinuousOn (Inv.inv : G₀ → G₀) {0}ᶜ := fun _x hx => (continuousAt_inv₀ hx).continuousWithinAt
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
continuousOn_inv₀
null
Filter.Tendsto.inv₀ {a : G₀} (hf : Tendsto f l (𝓝 a)) (ha : a ≠ 0) : Tendsto (fun x => (f x)⁻¹) l (𝓝 a⁻¹) := (tendsto_inv₀ ha).comp hf variable [TopologicalSpace α] nonrec theorem ContinuousWithinAt.inv₀ (hf : ContinuousWithinAt f s a) (ha : f a ≠ 0) : ContinuousWithinAt (fun x => (f x)⁻¹) s a := hf.inv₀ ha @[fun_prop] nonrec theorem ContinuousAt.inv₀ (hf : ContinuousAt f a) (ha : f a ≠ 0) : ContinuousAt (fun x => (f x)⁻¹) a := hf.inv₀ ha @[continuity, fun_prop]
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
Filter.Tendsto.inv₀
If a function converges to a nonzero value, its inverse converges to the inverse of this value. We use the name `Filter.Tendsto.inv₀` as `Filter.Tendsto.inv` is already used in multiplicative topological groups.
Continuous.inv₀ (hf : Continuous f) (h0 : ∀ x, f x ≠ 0) : Continuous fun x => (f x)⁻¹ := continuous_iff_continuousAt.2 fun x => (hf.tendsto x).inv₀ (h0 x) @[fun_prop]
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
Continuous.inv₀
null
ContinuousOn.inv₀ (hf : ContinuousOn f s) (h0 : ∀ x ∈ s, f x ≠ 0) : ContinuousOn (fun x => (f x)⁻¹) s := fun x hx => (hf x hx).inv₀ (h0 x hx)
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
ContinuousOn.inv₀
null
Units.isEmbedding_val₀ : IsEmbedding (val : G₀ˣ → G₀) := embedding_val_mk <| (continuousOn_inv₀ (G₀ := G₀)).mono fun _ ↦ IsUnit.ne_zero
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
Units.isEmbedding_val₀
If `G₀` is a group with zero with topology such that `x ↦ x⁻¹` is continuous at all nonzero points. Then the coercion `G₀ˣ → G₀` is a topological embedding.
noncomputable unitsHomeomorphNeZero : G₀ˣ ≃ₜ {g : G₀ // g ≠ 0} := Units.isEmbedding_val₀.toHomeomorph.trans <| show _ ≃ₜ {g | _} from .setCongr <| Set.ext fun x ↦ (Units.exists_iff_ne_zero (p := (· = x))).trans <| by simp
def
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
unitsHomeomorphNeZero
If a group with zero has continuous inversion, then its group of units is homeomorphic to the set of nonzero elements.
nhds_inv₀ (hx : x ≠ 0) : 𝓝 x⁻¹ = (𝓝 x)⁻¹ := by refine le_antisymm (inv_le_iff_le_inv.1 ?_) (tendsto_inv₀ hx) simpa only [inv_inv] using tendsto_inv₀ (inv_ne_zero hx)
lemma
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
nhds_inv₀
null
tendsto_inv_iff₀ {l : Filter α} {f : α → G₀} (hx : x ≠ 0) : Tendsto (fun x ↦ (f x)⁻¹) l (𝓝 x⁻¹) ↔ Tendsto f l (𝓝 x) := by simp only [nhds_inv₀ hx, ← Filter.comap_inv, tendsto_comap_iff, Function.comp_def, inv_inv]
lemma
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
tendsto_inv_iff₀
null
Filter.Tendsto.div {l : Filter α} {a b : G₀} (hf : Tendsto f l (𝓝 a)) (hg : Tendsto g l (𝓝 b)) (hy : b ≠ 0) : Tendsto (f / g) l (𝓝 (a / b)) := by simpa only [div_eq_mul_inv] using hf.mul (hg.inv₀ hy)
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
Filter.Tendsto.div
null
Filter.tendsto_mul_iff_of_ne_zero [T1Space G₀] {f g : α → G₀} {l : Filter α} {x y : G₀} (hg : Tendsto g l (𝓝 y)) (hy : y ≠ 0) : Tendsto (fun n => f n * g n) l (𝓝 <| x * y) ↔ Tendsto f l (𝓝 x) := by refine ⟨fun hfg => ?_, fun hf => hf.mul hg⟩ rw [← mul_div_cancel_right₀ x hy] refine Tendsto.congr' ?_ (hfg.div hg hy) exact (hg.eventually_ne hy).mono fun n hn => mul_div_cancel_right₀ _ hn variable [TopologicalSpace α] [TopologicalSpace β] {s : Set α} {a : α} nonrec theorem ContinuousWithinAt.div (hf : ContinuousWithinAt f s a) (hg : ContinuousWithinAt g s a) (h₀ : g a ≠ 0) : ContinuousWithinAt (f / g) s a := hf.div hg h₀
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
Filter.tendsto_mul_iff_of_ne_zero
null
ContinuousOn.div (hf : ContinuousOn f s) (hg : ContinuousOn g s) (h₀ : ∀ x ∈ s, g x ≠ 0) : ContinuousOn (f / g) s := fun x hx => (hf x hx).div (hg x hx) (h₀ x hx)
theorem
Topology
[ "Mathlib.Algebra.Group.Pi.Lemmas", "Mathlib.Algebra.GroupWithZero.Units.Equiv", "Mathlib.Topology.Algebra.Monoid", "Mathlib.Topology.Homeomorph.Lemmas" ]
Mathlib/Topology/Algebra/GroupWithZero.lean
ContinuousOn.div
null