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isClosed_union_iff (hst : SeparatedNhds s t) : IsClosed (s ∪ t) ↔ IsClosed s ∧ IsClosed t := ⟨fun h ↦ ⟨hst.isClosed_left_of_isClosed_union h, hst.isClosed_right_of_isClosed_union h⟩, fun ⟨h1, h2⟩ ↦ h1.union h2⟩
lemma
Topology
[ "Mathlib.Topology.Continuous", "Mathlib.Topology.NhdsSet" ]
Mathlib/Topology/Separation/SeparatedNhds.lean
isClosed_union_iff
null
Closeds (α : Type*) [TopologicalSpace α] where /-- the carrier set, i.e. the points in this set -/ carrier : Set α isClosed' : IsClosed carrier
structure
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Closeds
The type of closed subsets of a topological space.
isClosed (s : Closeds α) : IsClosed (s : Set α) := s.isClosed' @[deprecated (since := "2025-04-20")] alias closed := isClosed
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
isClosed
null
Simps.coe (s : Closeds α) : Set α := s initialize_simps_projections Closeds (carrier → coe, as_prefix coe) @[simp]
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Simps.coe
See Note [custom simps projection].
carrier_eq_coe (s : Closeds α) : s.carrier = (s : Set α) := rfl @[ext]
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
carrier_eq_coe
null
protected ext {s t : Closeds α} (h : (s : Set α) = t) : s = t := SetLike.ext' h @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
ext
null
coe_mk (s : Set α) (h) : (mk s h : Set α) = s := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
coe_mk
null
mem_mk {s : Set α} {hs : IsClosed s} {x : α} : x ∈ (⟨s, hs⟩ : Closeds α) ↔ x ∈ s := .rfl
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
mem_mk
null
@[simps] protected closure (s : Set α) : Closeds α := ⟨closure s, isClosed_closure⟩ @[simp]
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
closure
The closure of a set, as an element of `TopologicalSpace.Closeds`.
mem_closure {s : Set α} {x : α} : x ∈ Closeds.closure s ↔ x ∈ closure s := .rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
mem_closure
null
gc : GaloisConnection Closeds.closure ((↑) : Closeds α → Set α) := fun _ U => ⟨subset_closure.trans, fun h => closure_minimal h U.isClosed⟩ @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
gc
null
closure_le {s : Set α} {t : Closeds α} : .closure s ≤ t ↔ s ⊆ t := t.isClosed.closure_subset_iff
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
closure_le
null
gi : GaloisInsertion (@Closeds.closure α _) (↑) where choice s hs := ⟨s, closure_eq_iff_isClosed.1 <| hs.antisymm subset_closure⟩ gc := gc le_l_u _ := subset_closure choice_eq _s hs := SetLike.coe_injective <| subset_closure.antisymm hs
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
gi
The Galois insertion between sets and closeds.
instCompleteLattice : CompleteLattice (Closeds α) := CompleteLattice.copy (GaloisInsertion.liftCompleteLattice gi) _ rfl ⟨univ, isClosed_univ⟩ rfl ⟨∅, isClosed_empty⟩ (SetLike.coe_injective closure_empty.symm) (fun s t => ⟨s ∪ t, s.2.union t.2⟩) (funext fun s => funext fun t => SetLike.coe_inj...
instance
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
instCompleteLattice
null
coframeMinimalAxioms : Coframe.MinimalAxioms (Closeds α) where iInf_sup_le_sup_sInf a s := (SetLike.coe_injective <| by simp only [coe_sup, coe_iInf, coe_sInf, Set.union_iInter₂]).le
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
coframeMinimalAxioms
The type of closed sets is inhabited, with default element the empty set. -/ instance : Inhabited (Closeds α) := ⟨⊥⟩ @[simp, norm_cast] theorem coe_sup (s t : Closeds α) : (↑(s ⊔ t) : Set α) = ↑s ∪ ↑t := by rfl @[simp, norm_cast] theorem coe_inf (s t : Closeds α) : (↑(s ⊓ t) : Set α) = ↑s ∩ ↑t := rfl @[simp, n...
instCoframe : Coframe (Closeds α) := .ofMinimalAxioms coframeMinimalAxioms
instance
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
instCoframe
null
@[simps] singleton [T1Space α] (x : α) : Closeds α := ⟨{x}, isClosed_singleton⟩ @[simp] lemma mem_singleton [T1Space α] {a b : α} : a ∈ singleton b ↔ a = b := Iff.rfl
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
singleton
The term of `TopologicalSpace.Closeds α` corresponding to a singleton.
@[simps] preimage (s : Closeds β) {f : α → β} (hf : Continuous f) : Closeds α := ⟨f ⁻¹' s, s.isClosed.preimage hf⟩
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
preimage
The preimage of a closed set under a continuous map.
@[simps] Closeds.compl (s : Closeds α) : Opens α := ⟨sᶜ, s.2.isOpen_compl⟩
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Closeds.compl
The complement of a closed set as an open set.
@[simps] Opens.compl (s : Opens α) : Closeds α := ⟨sᶜ, s.2.isClosed_compl⟩ nonrec theorem Closeds.compl_compl (s : Closeds α) : s.compl.compl = s := Closeds.ext (compl_compl (s : Set α)) nonrec theorem Opens.compl_compl (s : Opens α) : s.compl.compl = s := Opens.ext (compl_compl (s : Set α))
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Opens.compl
The complement of an open set as a closed set.
Closeds.compl_bijective : Function.Bijective (@Closeds.compl α _) := Function.bijective_iff_has_inverse.mpr ⟨Opens.compl, Closeds.compl_compl, Opens.compl_compl⟩
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Closeds.compl_bijective
null
Opens.compl_bijective : Function.Bijective (@Opens.compl α _) := Function.bijective_iff_has_inverse.mpr ⟨Closeds.compl, Opens.compl_compl, Closeds.compl_compl⟩ variable (α)
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Opens.compl_bijective
null
@[simps] Closeds.complOrderIso : Closeds α ≃o (Opens α)ᵒᵈ where toFun := OrderDual.toDual ∘ Closeds.compl invFun := Opens.compl ∘ OrderDual.ofDual left_inv s := by simp [Closeds.compl_compl] right_inv s := by simp [Opens.compl_compl] map_rel_iff' := (@OrderDual.toDual_le_toDual (Opens α)).trans compl_subset_c...
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Closeds.complOrderIso
`TopologicalSpace.Closeds.compl` as an `OrderIso` to the order dual of `TopologicalSpace.Opens α`.
@[simps] Opens.complOrderIso : Opens α ≃o (Closeds α)ᵒᵈ where toFun := OrderDual.toDual ∘ Opens.compl invFun := Closeds.compl ∘ OrderDual.ofDual left_inv s := by simp [Opens.compl_compl] right_inv s := by simp [Closeds.compl_compl] map_rel_iff' := (@OrderDual.toDual_le_toDual (Closeds α)).trans compl_subset_c...
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Opens.complOrderIso
`TopologicalSpace.Opens.compl` as an `OrderIso` to the order dual of `TopologicalSpace.Closeds α`.
Closeds.coe_eq_singleton_of_isAtom [T0Space α] {s : Closeds α} (hs : IsAtom s) : ∃ a, (s : Set α) = {a} := by refine minimal_nonempty_closed_eq_singleton s.2 (coe_nonempty.2 hs.1) fun t hts ht ht' ↦ ?_ lift t to Closeds α using ht' exact SetLike.coe_injective.eq_iff.2 <| (hs.le_iff_eq <| coe_nonempty.1 ht).1 ...
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Closeds.coe_eq_singleton_of_isAtom
null
Closeds.isAtom_iff [T1Space α] {s : Closeds α} : IsAtom s ↔ ∃ x, s = Closeds.singleton x := by simp [← Closeds.isAtom_coe, Set.isAtom_iff, SetLike.ext_iff, Set.ext_iff]
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Closeds.isAtom_iff
in a `T1Space`, atoms of `TopologicalSpace.Closeds α` are precisely the `TopologicalSpace.Closeds.singleton`s.
Opens.isCoatom_iff [T1Space α] {s : Opens α} : IsCoatom s ↔ ∃ x, s = (Closeds.singleton x).compl := by rw [← s.compl_compl, ← isAtom_dual_iff_isCoatom] change IsAtom (Closeds.complOrderIso α s.compl) ↔ _ simp only [(Closeds.complOrderIso α).isAtom_iff, Closeds.isAtom_iff, Closeds.compl_bijective.injective...
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Opens.isCoatom_iff
in a `T1Space`, coatoms of `TopologicalSpace.Opens α` are precisely complements of singletons: `(TopologicalSpace.Closeds.singleton x).compl`.
Clopens (α : Type*) [TopologicalSpace α] where /-- the carrier set, i.e. the points in this set -/ carrier : Set α isClopen' : IsClopen carrier
structure
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Clopens
The type of clopen sets of a topological space.
isClopen (s : Clopens α) : IsClopen (s : Set α) := s.isClopen'
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
isClopen
null
isOpen (s : Clopens α) : IsOpen (s : Set α) := s.isClopen.isOpen
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
isOpen
null
isClosed (s : Clopens α) : IsClosed (s : Set α) := s.isClopen.isClosed
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
isClosed
null
Simps.coe (s : Clopens α) : Set α := s initialize_simps_projections Clopens (carrier → coe, as_prefix coe)
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Simps.coe
See Note [custom simps projection].
@[simps] toOpens (s : Clopens α) : Opens α := ⟨s, s.isOpen⟩
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
toOpens
Reinterpret a clopen as an open.
@[simps] toCloseds (s : Clopens α) : Closeds α := ⟨s, s.isClosed⟩ @[ext]
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
toCloseds
Reinterpret a clopen as a closed.
protected ext {s t : Clopens α} (h : (s : Set α) = t) : s = t := SetLike.ext' h @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
ext
null
coe_mk (s : Set α) (h) : (mk s h : Set α) = s := rfl @[simp] lemma mem_mk {s : Set α} {x h} : x ∈ mk s h ↔ x ∈ s := .rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
coe_mk
null
@[simp, norm_cast] coe_sup (s t : Clopens α) : ↑(s ⊔ t) = (s ∪ t : Set α) := rfl @[simp, norm_cast] lemma coe_inf (s t : Clopens α) : ↑(s ⊓ t) = (s ∩ t : Set α) := rfl @[simp, norm_cast] lemma coe_top : (↑(⊤ : Clopens α) : Set α) = univ := rfl @[simp, norm_cast] lemma coe_bot : (↑(⊥ : Clopens α) : Set α) = ∅ := rfl @[s...
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
coe_sup
null
@[simp] protected mem_prod {s : Clopens α} {t : Clopens β} {x : α × β} : x ∈ s ×ˢ t ↔ x.1 ∈ s ∧ x.2 ∈ t := .rfl @[simp]
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
mem_prod
null
coe_finset_sup (s : Finset ι) (U : ι → Clopens α) : (↑(s.sup U) : Set α) = ⋃ i ∈ s, U i := by classical induction s using Finset.induction_on with | empty => simp | insert _ _ _ IH => simp [IH] @[simp, norm_cast]
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
coe_finset_sup
null
coe_disjoint {s t : Clopens α} : Disjoint (s : Set α) t ↔ Disjoint s t := by simp [disjoint_iff, ← SetLike.coe_set_eq]
lemma
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
coe_disjoint
null
IrreducibleCloseds (α : Type*) [TopologicalSpace α] where /-- the carrier set, i.e. the points in this set -/ carrier : Set α is_irreducible' : IsIrreducible carrier is_closed' : IsClosed carrier
structure
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
IrreducibleCloseds
The type of irreducible closed subsets of a topological space.
isIrreducible (s : IrreducibleCloseds α) : IsIrreducible (s : Set α) := s.is_irreducible'
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
isIrreducible
null
isClosed (s : IrreducibleCloseds α) : IsClosed (s : Set α) := s.is_closed'
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
isClosed
null
Simps.coe (s : IrreducibleCloseds α) : Set α := s initialize_simps_projections IrreducibleCloseds (carrier → coe, as_prefix coe) @[ext]
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
Simps.coe
See Note [custom simps projection].
protected ext {s t : IrreducibleCloseds α} (h : (s : Set α) = t) : s = t := SetLike.ext' h @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
ext
null
coe_mk (s : Set α) (h : IsIrreducible s) (h' : IsClosed s) : (mk s h h' : Set α) = s := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
coe_mk
null
@[simps] singleton [T1Space α] (x : α) : IrreducibleCloseds α := ⟨{x}, isIrreducible_singleton, isClosed_singleton⟩ @[simp] lemma mem_singleton [T1Space α] {a b : α} : a ∈ singleton b ↔ a = b := Iff.rfl
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
singleton
The term of `TopologicalSpace.IrreducibleCloseds α` corresponding to a singleton.
@[simps apply symm_apply] equivSubtype : IrreducibleCloseds α ≃ { x : Set α // IsIrreducible x ∧ IsClosed x } where toFun a := ⟨a.1, a.2, a.3⟩ invFun a := ⟨a.1, a.2.1, a.2.2⟩
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
equivSubtype
The equivalence between `IrreducibleCloseds α` and `{x : Set α // IsIrreducible x ∧ IsClosed x }`.
@[simps apply symm_apply] equivSubtype' : IrreducibleCloseds α ≃ { x : Set α // IsClosed x ∧ IsIrreducible x } where toFun a := ⟨a.1, a.3, a.2⟩ invFun a := ⟨a.1, a.2.2, a.2.1⟩ variable (α) in
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
equivSubtype'
The equivalence between `IrreducibleCloseds α` and `{x : Set α // IsClosed x ∧ IsIrreducible x }`.
orderIsoSubtype : IrreducibleCloseds α ≃o { x : Set α // IsIrreducible x ∧ IsClosed x } := equivSubtype.toOrderIso (fun _ _ h ↦ h) (fun _ _ h ↦ h) variable (α) in
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
orderIsoSubtype
The equivalence `IrreducibleCloseds α ≃ { x : Set α // IsIrreducible x ∧ IsClosed x }` is an order isomorphism.
orderIsoSubtype' : IrreducibleCloseds α ≃o { x : Set α // IsClosed x ∧ IsIrreducible x } := equivSubtype'.toOrderIso (fun _ _ h ↦ h) (fun _ _ h ↦ h)
def
Topology
[ "Mathlib.Topology.Sets.Opens", "Mathlib.Topology.Clopen" ]
Mathlib/Topology/Sets/Closeds.lean
orderIsoSubtype'
The equivalence `IrreducibleCloseds α ≃ { x : Set α // IsClosed x ∧ IsIrreducible x }` is an order isomorphism.
IsCompactOpenCovered {S ι : Type*} {X : ι → Type*} (f : ∀ i, X i → S) [∀ i, TopologicalSpace (X i)] (U : Set S) : Prop := ∃ (s : Set ι) (_ : s.Finite) (V : ∀ i ∈ s, Opens (X i)), (∀ (i : ι) (h : i ∈ s), IsCompact (V i h).1) ∧ ⋃ (i : ι) (h : i ∈ s), (f i) '' (V i h) = U
def
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
IsCompactOpenCovered
A set `U` is compact-open covered by the family `fᵢ : X i → S`, if `U` is the finite union of images of compact open sets in the `X i`.
empty : IsCompactOpenCovered f ∅ := ⟨∅, Set.finite_empty, fun _ _ ↦ ⟨∅, isOpen_empty⟩, fun _ _ ↦ isCompact_empty, by simp⟩
lemma
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
empty
null
iff_of_unique [Unique ι] : IsCompactOpenCovered f U ↔ ∃ (V : Opens (X default)), IsCompact V.1 ∧ f default '' V.1 = U := by refine ⟨fun ⟨s, hs, V, hc, hcov⟩ ↦ ?_, fun ⟨V, hc, h⟩ ↦ ?_⟩ · by_cases h : s = ∅ · aesop · obtain rfl : s = {default} := by rw [← Set.univ_unique, Subsingleton.eq_univ_of_n...
lemma
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
iff_of_unique
null
id_iff_isOpen_and_isCompact [TopologicalSpace S] : IsCompactOpenCovered (fun _ : Unit ↦ id) U ↔ IsOpen U ∧ IsCompact U := by rw [iff_of_unique] refine ⟨fun ⟨V, hV, heq⟩ ↦ ?_, fun ⟨ho, hc⟩ ↦ ⟨⟨U, ho⟩, hc, by simp⟩⟩ simp only [id_eq, Set.image_id', carrier_eq_coe, ← heq] at heq ⊢ exact ⟨V.2, hV⟩
lemma
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
id_iff_isOpen_and_isCompact
null
iff_isCompactOpenCovered_sigmaMk : IsCompactOpenCovered f U ↔ IsCompactOpenCovered (fun (_ : Unit) (p : Σ i : ι, X i) ↦ f p.1 p.2) U := by classical rw [iff_of_unique (ι := Unit)] refine ⟨fun ⟨s, hs, V, hc, hU⟩ ↦ ?_, fun ⟨V, hc, heq⟩ ↦ ?_⟩ · refine ⟨⟨s.sigma fun i ↦ if h : i ∈ s then V i h else ∅, isO...
lemma
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
iff_isCompactOpenCovered_sigmaMk
null
of_iUnion_eq_of_finite (s : Set (Set S)) (hs : ⋃ t ∈ s, t = U) (hf : s.Finite) (H : ∀ t ∈ s, IsCompactOpenCovered f t) : IsCompactOpenCovered f U := by rw [iff_isCompactOpenCovered_sigmaMk, iff_of_unique] have (t) (h : t ∈ s) : ∃ (V : Opens (Σ i, X i)), IsCompact V.1 ∧ (fun p ↦ f p.fst p.snd) '' V.carrier...
lemma
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
of_iUnion_eq_of_finite
null
exists_mem_of_isBasis {B : ∀ i, Set (Opens (X i))} (hB : ∀ i, IsBasis (B i)) (hBc : ∀ (i : ι), ∀ U ∈ B i, IsCompact U.1) {U : Set S} (hU : IsCompactOpenCovered f U) : ∃ (n : ℕ) (a : Fin n → ι) (V : ∀ i, Opens (X (a i))), (∀ i, V i ∈ B (a i)) ∧ ⋃ i, f (a i) '' V i = U := by suffices h : ∃ (κ : Type _...
lemma
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
exists_mem_of_isBasis
If `U` is compact-open covered and the `X i` have a basis of compact opens, `U` can be written as the union of images of elements of the basis.
of_isOpenMap [TopologicalSpace S] [∀ i, PrespectralSpace (X i)] (hfc : ∀ i, Continuous (f i)) (h : ∀ i, IsOpenMap (f i)) {U : Set S} (hs : ∀ x ∈ U, ∃ i y, f i y = x) (hU : IsOpen U) (hc : IsCompact U) : IsCompactOpenCovered f U := by rw [iff_isCompactOpenCovered_sigmaMk, iff_of_unique] refine (isOpenMap...
lemma
Topology
[ "Mathlib.Data.Finite.Sigma", "Mathlib.Topology.Spectral.Prespectral" ]
Mathlib/Topology/Sets/CompactOpenCovered.lean
of_isOpenMap
null
Compacts (α : Type*) [TopologicalSpace α] where /-- the carrier set, i.e. the points in this set -/ carrier : Set α isCompact' : IsCompact carrier
structure
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
Compacts
The type of compact sets of a topological space.
Simps.coe (s : Compacts α) : Set α := s initialize_simps_projections Compacts (carrier → coe, as_prefix coe)
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
Simps.coe
See Note [custom simps projection].
protected isCompact (s : Compacts α) : IsCompact (s : Set α) := s.isCompact'
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
isCompact
null
@[ext] protected ext {s t : Compacts α} (h : (s : Set α) = t) : s = t := SetLike.ext' h @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
ext
null
coe_mk (s : Set α) (h) : (mk s h : Set α) = s := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_mk
null
carrier_eq_coe (s : Compacts α) : s.carrier = s := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
carrier_eq_coe
null
protected map (f : α → β) (hf : Continuous f) (K : Compacts α) : Compacts β := ⟨f '' K.1, K.2.image hf⟩ @[simp, norm_cast]
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
map
The type of compact sets is inhabited, with default element the empty set. -/ instance : Inhabited (Compacts α) := ⟨⊥⟩ @[simp] theorem coe_sup (s t : Compacts α) : (↑(s ⊔ t) : Set α) = ↑s ∪ ↑t := rfl @[simp] theorem coe_inf [T2Space α] (s t : Compacts α) : (↑(s ⊓ t) : Set α) = ↑s ∩ ↑t := rfl @[simp] theorem coe_...
coe_map {f : α → β} (hf : Continuous f) (s : Compacts α) : (s.map f hf : Set β) = f '' s := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_map
null
map_id (K : Compacts α) : K.map id continuous_id = K := Compacts.ext <| Set.image_id _
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
map_id
null
map_comp (f : β → γ) (g : α → β) (hf : Continuous f) (hg : Continuous g) (K : Compacts α) : K.map (f ∘ g) (hf.comp hg) = (K.map g hg).map f hf := Compacts.ext <| Set.image_comp _ _ _
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
map_comp
null
@[simps] protected equiv (f : α ≃ₜ β) : Compacts α ≃ Compacts β where toFun := Compacts.map f f.continuous invFun := Compacts.map _ f.symm.continuous left_inv s := by ext1 simp only [coe_map, ← image_comp, f.symm_comp_self, image_id] right_inv s := by ext1 simp only [coe_map, ← image_comp, f.sel...
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
equiv
A homeomorphism induces an equivalence on compact sets, by taking the image.
equiv_refl : Compacts.equiv (Homeomorph.refl α) = Equiv.refl _ := Equiv.ext map_id @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
equiv_refl
null
equiv_trans (f : α ≃ₜ β) (g : β ≃ₜ γ) : Compacts.equiv (f.trans g) = (Compacts.equiv f).trans (Compacts.equiv g) := Equiv.ext <| map_comp g f g.continuous f.continuous @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
equiv_trans
null
equiv_symm (f : α ≃ₜ β) : Compacts.equiv f.symm = (Compacts.equiv f).symm := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
equiv_symm
null
coe_equiv_apply_eq_preimage (f : α ≃ₜ β) (K : Compacts α) : (Compacts.equiv f K : Set β) = f.symm ⁻¹' (K : Set α) := f.toEquiv.image_eq_preimage K
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_equiv_apply_eq_preimage
The image of a compact set under a homeomorphism can also be expressed as a preimage.
protected prod (K : Compacts α) (L : Compacts β) : Compacts (α × β) where carrier := K ×ˢ L isCompact' := IsCompact.prod K.2 L.2 @[simp]
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
prod
The product of two `TopologicalSpace.Compacts`, as a `TopologicalSpace.Compacts` in the product space.
coe_prod (K : Compacts α) (L : Compacts β) : (K.prod L : Set (α × β)) = (K : Set α) ×ˢ (L : Set β) := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_prod
null
NonemptyCompacts (α : Type*) [TopologicalSpace α] extends Compacts α where nonempty' : carrier.Nonempty
structure
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
NonemptyCompacts
The type of nonempty compact sets of a topological space.
Simps.coe (s : NonemptyCompacts α) : Set α := s initialize_simps_projections NonemptyCompacts (carrier → coe, as_prefix coe)
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
Simps.coe
See Note [custom simps projection].
protected isCompact (s : NonemptyCompacts α) : IsCompact (s : Set α) := s.isCompact'
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
isCompact
null
protected nonempty (s : NonemptyCompacts α) : (s : Set α).Nonempty := s.nonempty'
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
nonempty
null
toCloseds [T2Space α] (s : NonemptyCompacts α) : Closeds α := ⟨s, s.isCompact.isClosed⟩ @[ext]
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
toCloseds
Reinterpret a nonempty compact as a closed set.
protected ext {s t : NonemptyCompacts α} (h : (s : Set α) = t) : s = t := SetLike.ext' h @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
ext
null
coe_mk (s : Compacts α) (h) : (mk s h : Set α) = s := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_mk
null
carrier_eq_coe (s : NonemptyCompacts α) : s.carrier = s := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
carrier_eq_coe
null
coe_toCompacts (s : NonemptyCompacts α) : (s.toCompacts : Set α) = s := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_toCompacts
null
@[simp] coe_sup (s t : NonemptyCompacts α) : (↑(s ⊔ t) : Set α) = ↑s ∪ ↑t := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_sup
null
coe_top [CompactSpace α] [Nonempty α] : (↑(⊤ : NonemptyCompacts α) : Set α) = univ := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_top
null
protected prod (K : NonemptyCompacts α) (L : NonemptyCompacts β) : NonemptyCompacts (α × β) := { K.toCompacts.prod L.toCompacts with nonempty' := K.nonempty.prod L.nonempty } @[simp]
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
prod
In an inhabited space, the type of nonempty compact subsets is also inhabited, with default element the singleton set containing the default element. -/ instance [Inhabited α] : Inhabited (NonemptyCompacts α) := ⟨{ carrier := {default} isCompact' := isCompact_singleton nonempty' := singleton_nonempty _ }...
coe_prod (K : NonemptyCompacts α) (L : NonemptyCompacts β) : (K.prod L : Set (α × β)) = (K : Set α) ×ˢ (L : Set β) := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_prod
null
PositiveCompacts (α : Type*) [TopologicalSpace α] extends Compacts α where interior_nonempty' : (interior carrier).Nonempty
structure
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
PositiveCompacts
The type of compact sets with nonempty interior of a topological space. See also `TopologicalSpace.Compacts` and `TopologicalSpace.NonemptyCompacts`.
Simps.coe (s : PositiveCompacts α) : Set α := s initialize_simps_projections PositiveCompacts (carrier → coe, as_prefix coe)
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
Simps.coe
See Note [custom simps projection].
protected isCompact (s : PositiveCompacts α) : IsCompact (s : Set α) := s.isCompact'
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
isCompact
null
interior_nonempty (s : PositiveCompacts α) : (interior (s : Set α)).Nonempty := s.interior_nonempty'
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
interior_nonempty
null
protected nonempty (s : PositiveCompacts α) : (s : Set α).Nonempty := s.interior_nonempty.mono interior_subset
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
nonempty
null
toNonemptyCompacts (s : PositiveCompacts α) : NonemptyCompacts α := ⟨s.toCompacts, s.nonempty⟩ @[ext]
def
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
toNonemptyCompacts
Reinterpret a positive compact as a nonempty compact.
protected ext {s t : PositiveCompacts α} (h : (s : Set α) = t) : s = t := SetLike.ext' h @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
ext
null
coe_mk (s : Compacts α) (h) : (mk s h : Set α) = s := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_mk
null
carrier_eq_coe (s : PositiveCompacts α) : s.carrier = s := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
carrier_eq_coe
null
coe_toCompacts (s : PositiveCompacts α) : (s.toCompacts : Set α) = s := rfl
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_toCompacts
null
@[simp] coe_sup (s t : PositiveCompacts α) : (↑(s ⊔ t) : Set α) = ↑s ∪ ↑t := rfl @[simp]
theorem
Topology
[ "Mathlib.Topology.Sets.Closeds", "Mathlib.Topology.QuasiSeparated" ]
Mathlib/Topology/Sets/Compacts.lean
coe_sup
null