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continuous_on_extend_from [regular_space Y] {f : X → Y} {A B : set X} (hB : B ⊆ closure A) (hf : ∀ x ∈ B, ∃ y, tendsto f (𝓝[A] x) (𝓝 y)) : continuous_on (extend_from A f) B
begin set φ := extend_from A f, intros x x_in, suffices : ∀ V' ∈ 𝓝 (φ x), is_closed V' → φ ⁻¹' V' ∈ 𝓝[B] x, by simpa [continuous_within_at, (closed_nhds_basis _).tendsto_right_iff], intros V' V'_in V'_closed, obtain ⟨V, V_in, V_op, hV⟩ : ∃ V ∈ 𝓝 x, is_open V ∧ V ∩ A ⊆ f ⁻¹' V', { have := tendsto_exte...
lemma
continuous_on_extend_from
topology
src/topology/extend_from.lean
[ "topology.separation" ]
[ "closed_nhds_basis", "closure", "continuous_on", "continuous_within_at", "extend_from", "inter_mem_nhds_within", "is_closed", "is_open", "is_open.mem_nhds", "nhds_within_basis_open", "regular_space", "tendsto_extend_from" ]
If `f` is a function to a T₃ space `Y` which has a limit within `A` at any point of a set `B ⊆ closure A`, then `extend_from A f` is continuous on `B`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_extend_from [regular_space Y] {f : X → Y} {A : set X} (hA : dense A) (hf : ∀ x, ∃ y, tendsto f (𝓝[A] x) (𝓝 y)) : continuous (extend_from A f)
begin rw continuous_iff_continuous_on_univ, exact continuous_on_extend_from (λ x _, hA x) (by simpa using hf) end
lemma
continuous_extend_from
topology
src/topology/extend_from.lean
[ "topology.separation" ]
[ "continuous", "continuous_iff_continuous_on_univ", "continuous_on_extend_from", "dense", "extend_from", "regular_space" ]
If a function `f` to a T₃ space `Y` has a limit within a dense set `A` for any `x`, then `extend_from A f` is continuous.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
extremally_disconnected : Prop
(open_closure : ∀ U : set X, is_open U → is_open (closure U))
class
extremally_disconnected
topology
src/topology/extremally_disconnected.lean
[ "topology.stone_cech" ]
[ "closure", "is_open" ]
An extremally disconnected topological space is a space in which the closure of every open set is open.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
compact_t2.projective : Prop
Π {Y Z : Type u} [topological_space Y] [topological_space Z], by exactI Π [compact_space Y] [t2_space Y] [compact_space Z] [t2_space Z], Π {f : X → Z} {g : Y → Z} (hf : continuous f) (hg : continuous g) (g_sur : surjective g), ∃ h : X → Y, continuous h ∧ g ∘ h = f
def
compact_t2.projective
topology
src/topology/extremally_disconnected.lean
[ "topology.stone_cech" ]
[ "compact_space", "continuous", "t2_space", "topological_space" ]
The assertion `compact_t2.projective` states that given continuous maps `f : X → Z` and `g : Y → Z` with `g` surjective between `t_2`, compact topological spaces, there exists a continuous lift `h : X → Y`, such that `f = g ∘ h`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
stone_cech.projective [discrete_topology X] : compact_t2.projective (stone_cech X)
begin introsI Y Z _tsY _tsZ _csY _t2Y _csZ _csZ f g hf hg g_sur, let s : Z → Y := λ z, classical.some $ g_sur z, have hs : g ∘ s = id := funext (λ z, classical.some_spec (g_sur z)), let t := s ∘ f ∘ stone_cech_unit, have ht : continuous t := continuous_of_discrete_topology, let h : stone_cech X → Y := stone...
lemma
stone_cech.projective
topology
src/topology/extremally_disconnected.lean
[ "topology.stone_cech" ]
[ "compact_t2.projective", "continuous", "continuous_of_discrete_topology", "continuous_stone_cech_extend", "discrete_topology", "stone_cech", "stone_cech_extend", "stone_cech_extend_extends", "stone_cech_unit" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
compact_t2.projective.extremally_disconnected [compact_space X] [t2_space X] (h : compact_t2.projective X) : extremally_disconnected X
begin refine { open_closure := λ U hU, _ }, let Z₁ : set (X × bool) := Uᶜ ×ˢ {tt}, let Z₂ : set (X × bool) := closure U ×ˢ {ff}, let Z : set (X × bool) := Z₁ ∪ Z₂, have hZ₁₂ : disjoint Z₁ Z₂ := disjoint_left.2 (λ x hx₁ hx₂, by cases hx₁.2.symm.trans hx₂.2), have hZ₁ : is_closed Z₁ := hU.is_closed_compl.prod...
lemma
compact_t2.projective.extremally_disconnected
topology
src/topology/extremally_disconnected.lean
[ "topology.stone_cech" ]
[ "closure", "closure_minimal", "compact_space", "compact_t2.projective", "continuous", "continuous_id", "continuous_subtype_val", "disjoint", "extremally_disconnected", "is_closed", "set.mem_singleton", "set.preimage_comp", "t2_space" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_Iic_principal {s : set α} : is_open (Iic (𝓟 s))
generate_open.basic _ (mem_range_self _)
lemma
filter.is_open_Iic_principal
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_set_of_mem {s : set α} : is_open {l : filter α | s ∈ l}
by simpa only [Iic_principal] using is_open_Iic_principal
lemma
filter.is_open_set_of_mem
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_topological_basis_Iic_principal : is_topological_basis (range (Iic ∘ 𝓟 : set α → set (filter α)))
{ exists_subset_inter := begin rintro _ ⟨s, rfl⟩ _ ⟨t, rfl⟩ l hl, exact ⟨Iic (𝓟 s) ∩ Iic (𝓟 t), ⟨s ∩ t, by simp⟩, hl, subset.rfl⟩ end, sUnion_eq := sUnion_eq_univ_iff.2 $ λ l, ⟨Iic ⊤, ⟨univ, congr_arg Iic principal_univ⟩, le_top⟩, eq_generate_from := rfl }
lemma
filter.is_topological_basis_Iic_principal
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_iff {s : set (filter α)} : is_open s ↔ ∃ T : set (set α), s = ⋃ t ∈ T, Iic (𝓟 t)
is_topological_basis_Iic_principal.open_iff_eq_sUnion.trans $ by simp only [exists_subset_range_iff, sUnion_image]
lemma
filter.is_open_iff
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_eq (l : filter α) : 𝓝 l = l.lift' (Iic ∘ 𝓟)
nhds_generate_from.trans $ by simp only [mem_set_of_eq, and_comm (l ∈ _), infi_and, infi_range, filter.lift', filter.lift, (∘), mem_Iic, le_principal_iff]
lemma
filter.nhds_eq
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "filter.lift", "filter.lift'", "infi_and", "infi_range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_eq' (l : filter α) : 𝓝 l = l.lift' (λ s, {l' | s ∈ l'})
by simpa only [(∘), Iic_principal] using nhds_eq l
lemma
filter.nhds_eq'
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_nhds {la : filter α} {lb : filter β} {f : α → filter β} : tendsto f la (𝓝 lb) ↔ ∀ s ∈ lb, ∀ᶠ a in la, s ∈ f a
by simp only [nhds_eq', tendsto_lift', mem_set_of_eq]
lemma
filter.tendsto_nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "tendsto_nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_basis.nhds {l : filter α} {p : ι → Prop} {s : ι → set α} (h : has_basis l p s) : has_basis (𝓝 l) p (λ i, Iic (𝓟 (s i)))
by { rw nhds_eq, exact h.lift' monotone_principal.Iic }
lemma
filter.has_basis.nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_basis.nhds' {l : filter α} {p : ι → Prop} {s : ι → set α} (h : has_basis l p s) : has_basis (𝓝 l) p (λ i, {l' | s i ∈ l'})
by simpa only [Iic_principal] using h.nhds
lemma
filter.has_basis.nhds'
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_iff {l : filter α} {S : set (filter α)} : S ∈ 𝓝 l ↔ ∃ t ∈ l, Iic (𝓟 t) ⊆ S
l.basis_sets.nhds.mem_iff
lemma
filter.mem_nhds_iff
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "mem_nhds_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_nhds_iff' {l : filter α} {S : set (filter α)} : S ∈ 𝓝 l ↔ ∃ t ∈ l, ∀ ⦃l' : filter α⦄, t ∈ l' → l' ∈ S
l.basis_sets.nhds'.mem_iff
lemma
filter.mem_nhds_iff'
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_bot : 𝓝 (⊥ : filter α) = pure ⊥
by simp [nhds_eq, lift'_bot monotone_principal.Iic]
lemma
filter.nhds_bot
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_top : 𝓝 (⊤ : filter α) = ⊤
by simp [nhds_eq]
lemma
filter.nhds_top
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "nhds_top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_principal (s : set α) : 𝓝 (𝓟 s) = 𝓟 (Iic (𝓟 s))
(has_basis_principal s).nhds.eq_of_same_basis (has_basis_principal _)
lemma
filter.nhds_principal
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_pure (x : α) : 𝓝 (pure x : filter α) = 𝓟 {⊥, pure x}
by rw [← principal_singleton, nhds_principal, principal_singleton, Iic_pure]
lemma
filter.nhds_pure
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_infi (f : ι → filter α) : 𝓝 (⨅ i, f i) = ⨅ i, 𝓝 (f i)
by { simp only [nhds_eq], apply lift'_infi_of_map_univ; simp }
lemma
filter.nhds_infi
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "nhds_infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_inf (l₁ l₂ : filter α) : 𝓝 (l₁ ⊓ l₂) = 𝓝 l₁ ⊓ 𝓝 l₂
by simpa only [infi_bool_eq] using nhds_infi (λ b, cond b l₁ l₂)
lemma
filter.nhds_inf
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "infi_bool_eq", "nhds_inf", "nhds_infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
monotone_nhds : monotone (𝓝 : filter α → filter (filter α))
monotone.of_map_inf nhds_inf
lemma
filter.monotone_nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "monotone", "monotone.of_map_inf", "nhds_inf" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Inter_nhds (l : filter α) : ⋂₀ {s | s ∈ 𝓝 l} = Iic l
by simp only [nhds_eq, sInter_lift'_sets monotone_principal.Iic, Iic, le_principal_iff, ← set_of_forall, ← filter.le_def]
lemma
filter.Inter_nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "filter.le_def" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_mono {l₁ l₂ : filter α} : 𝓝 l₁ ≤ 𝓝 l₂ ↔ l₁ ≤ l₂
begin refine ⟨λ h, _, λ h, monotone_nhds h⟩, rw [← Iic_subset_Iic, ← Inter_nhds, ← Inter_nhds], exact sInter_subset_sInter h end
lemma
filter.nhds_mono
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "nhds_mono" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_interior {s : set (filter α)} {l : filter α} : l ∈ interior s ↔ ∃ t ∈ l, Iic (𝓟 t) ⊆ s
by rw [mem_interior_iff_mem_nhds, mem_nhds_iff]
lemma
filter.mem_interior
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "interior", "mem_interior", "mem_interior_iff_mem_nhds", "mem_nhds_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_closure {s : set (filter α)} {l : filter α} : l ∈ closure s ↔ ∀ t ∈ l, ∃ l' ∈ s, t ∈ l'
by simp only [closure_eq_compl_interior_compl, filter.mem_interior, mem_compl_iff, not_exists, not_forall, not_not, exists_prop, not_and, and_comm, subset_def, mem_Iic, le_principal_iff]
lemma
filter.mem_closure
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "closure", "closure_eq_compl_interior_compl", "exists_prop", "filter", "filter.mem_interior", "not_and", "not_exists", "not_forall", "not_not" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
closure_singleton (l : filter α) : closure {l} = Ici l
by { ext l', simp [filter.mem_closure, filter.le_def] }
lemma
filter.closure_singleton
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "closure", "closure_singleton", "filter", "filter.le_def", "filter.mem_closure" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
specializes_iff_le {l₁ l₂ : filter α} : l₁ ⤳ l₂ ↔ l₁ ≤ l₂
by simp only [specializes_iff_closure_subset, filter.closure_singleton, Ici_subset_Ici]
lemma
filter.specializes_iff_le
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "filter.closure_singleton", "specializes_iff_closure_subset" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_at_top [preorder α] : 𝓝 at_top = ⨅ x : α, 𝓟 (Iic (𝓟 (Ici x)))
by simp only [at_top, nhds_infi, nhds_principal]
lemma
filter.nhds_at_top
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "nhds_infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_nhds_at_top_iff [preorder β] {l : filter α} {f : α → filter β} : tendsto f l (𝓝 at_top) ↔ ∀ y, ∀ᶠ a in l, Ici y ∈ f a
by simp only [nhds_at_top, tendsto_infi, tendsto_principal, mem_Iic, le_principal_iff]
lemma
filter.tendsto_nhds_at_top_iff
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_at_bot [preorder α] : 𝓝 at_bot = ⨅ x : α, 𝓟 (Iic (𝓟 (Iic x)))
@nhds_at_top αᵒᵈ _
lemma
filter.nhds_at_bot
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto_nhds_at_bot_iff [preorder β] {l : filter α} {f : α → filter β} : tendsto f l (𝓝 at_bot) ↔ ∀ y, ∀ᶠ a in l, Iic y ∈ f a
@filter.tendsto_nhds_at_top_iff α βᵒᵈ _ _ _
lemma
filter.tendsto_nhds_at_bot_iff
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "filter.tendsto_nhds_at_top_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nhds_nhds (x : X) : 𝓝 (𝓝 x) = ⨅ (s : set X) (hs : is_open s) (hx : x ∈ s), 𝓟 (Iic (𝓟 s))
by simp only [(nhds_basis_opens x).nhds.eq_binfi, infi_and, @infi_comm _ (_ ∈ _)]
lemma
filter.nhds_nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "infi_and", "infi_comm", "is_open", "nhds_basis_opens" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inducing_nhds : inducing (𝓝 : X → filter X)
inducing_iff_nhds.2 $ λ x, (nhds_def' _).trans $ by simp only [nhds_nhds, comap_infi, comap_principal, Iic_principal, preimage_set_of_eq, ← mem_interior_iff_mem_nhds, set_of_mem_eq, is_open.interior_eq] { contextual := tt }
lemma
filter.inducing_nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter", "inducing", "is_open.interior_eq", "mem_interior_iff_mem_nhds", "nhds_def'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_nhds : continuous (𝓝 : X → filter X)
inducing_nhds.continuous
lemma
filter.continuous_nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "continuous", "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
tendsto.nhds {f : α → X} {l : filter α} {x : X} (h : tendsto f l (𝓝 x)) : tendsto (𝓝 ∘ f) l (𝓝 (𝓝 x))
(continuous_nhds.tendsto _).comp h
lemma
filter.tendsto.nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "filter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_within_at.nhds (h : continuous_within_at f s x) : continuous_within_at (𝓝 ∘ f) s x
h.nhds
lemma
continuous_within_at.nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "continuous_within_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_at.nhds (h : continuous_at f x) : continuous_at (𝓝 ∘ f) x
h.nhds
lemma
continuous_at.nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "continuous_at" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous_on.nhds (h : continuous_on f s) : continuous_on (𝓝 ∘ f) s
λ x hx, (h x hx).nhds
lemma
continuous_on.nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "continuous_on", "nhds" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
continuous.nhds (h : continuous f) : continuous (𝓝 ∘ f)
filter.continuous_nhds.comp h
lemma
continuous.nhds
topology
src/topology/filter.lean
[ "order.filter.lift", "topology.separation", "data.set.intervals.monotone" ]
[ "continuous" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
glue_data extends glue_data Top
(f_open : ∀ i j, open_embedding (f i j)) (f_mono := λ i j, (Top.mono_iff_injective _).mpr (f_open i j).to_embedding.inj)
structure
Top.glue_data
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top", "Top.mono_iff_injective", "open_embedding" ]
A family of gluing data consists of 1. An index type `J` 2. An object `U i` for each `i : J`. 3. An object `V i j` for each `i j : J`. (Note that this is `J × J → Top` rather than `J → J → Top` to connect to the limits library easier.) 4. An open embedding `f i j : V i j ⟶ U i` for each `i j : ι`. 5. A transition m...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
π_surjective : function.surjective 𝖣 .π
(Top.epi_iff_surjective 𝖣 .π).mp infer_instance
lemma
Top.glue_data.π_surjective
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.epi_iff_surjective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open_iff (U : set 𝖣 .glued) : is_open U ↔ ∀ i, is_open (𝖣 .ι i ⁻¹' U)
begin delta category_theory.glue_data.ι, simp_rw ← multicoequalizer.ι_sigma_π 𝖣 .diagram, rw ← (homeo_of_iso (multicoequalizer.iso_coequalizer 𝖣 .diagram).symm).is_open_preimage, rw [coequalizer_is_open_iff, colimit_is_open_iff.{u}], split, { intros h j, exact h ⟨j⟩, }, { intros h j, cases j, exact h j,...
lemma
Top.glue_data.is_open_iff
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "category_theory.glue_data.ι", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_jointly_surjective (x : 𝖣 .glued) : ∃ i (y : D.U i), 𝖣 .ι i y = x
𝖣 .ι_jointly_surjective (forget Top) x
lemma
Top.glue_data.ι_jointly_surjective
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel (a b : Σ i, ((D.U i : Top) : Type*)) : Prop
a = b ∨ ∃ (x : D.V (a.1, b.1)) , D.f _ _ x = a.2 ∧ D.f _ _ (D.t _ _ x) = b.2
def
Top.glue_data.rel
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top", "rel" ]
An equivalence relation on `Σ i, D.U i` that holds iff `𝖣 .ι i x = 𝖣 .ι j y`. See `Top.glue_data.ι_eq_iff_rel`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel_equiv : equivalence D.rel
⟨ λ x, or.inl (refl x), begin rintros a b (⟨⟨⟩⟩|⟨x,e₁,e₂⟩), exacts [or.inl rfl, or.inr ⟨D.t _ _ x, by simp [e₁, e₂]⟩] end, begin rintros ⟨i,a⟩ ⟨j,b⟩ ⟨k,c⟩ (⟨⟨⟩⟩|⟨x,e₁,e₂⟩), exact id, rintro (⟨⟨⟩⟩|⟨y,e₃,e₄⟩), exact or.inr ⟨x,e₁,e₂⟩, let z := (pullback_iso_prod_subtype (D.f j i) (D.f j k)).inv ⟨...
lemma
Top.glue_data.rel_equiv
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "continuous_map.congr_fun" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eqv_gen_of_π_eq {x y : ∐ D.U} (h : 𝖣 .π x = 𝖣 .π y) : eqv_gen (types.coequalizer_rel 𝖣 .diagram.fst_sigma_map 𝖣 .diagram.snd_sigma_map) x y
begin delta glue_data.π multicoequalizer.sigma_π at h, simp_rw comp_app at h, replace h := (Top.mono_iff_injective (multicoequalizer.iso_coequalizer 𝖣 .diagram).inv).mp _ h, let diagram := parallel_pair 𝖣 .diagram.fst_sigma_map 𝖣 .diagram.snd_sigma_map ⋙ forget _, have : colimit.ι diagram one x = colimit.ι...
lemma
Top.glue_data.eqv_gen_of_π_eq
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.mono_iff_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_eq_iff_rel (i j : D.J) (x : D.U i) (y : D.U j) : 𝖣 .ι i x = 𝖣 .ι j y ↔ D.rel ⟨i, x⟩ ⟨j, y⟩
begin split, { delta glue_data.ι, simp_rw ← multicoequalizer.ι_sigma_π, intro h, rw ← (show _ = sigma.mk i x, from concrete_category.congr_hom (sigma_iso_sigma.{u} D.U).inv_hom_id _), rw ← (show _ = sigma.mk j y, from concrete_category.congr_hom (sigma_iso_sigma.{u} D.U).inv_hom_id _), ...
lemma
Top.glue_data.ι_eq_iff_rel
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.comp_app", "Top.sigma_iso_sigma_inv_apply", "continuous_map.to_fun_eq_coe", "eqv_gen.mono", "inv_image.equivalence" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_injective (i : D.J) : function.injective (𝖣 .ι i)
begin intros x y h, rcases (D.ι_eq_iff_rel _ _ _ _).mp h with (⟨⟨⟩⟩|⟨_,e₁,e₂⟩), { refl }, { dsimp only at *, cases e₁, cases e₂, simp } end
lemma
Top.glue_data.ι_injective
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_mono (i : D.J) : mono (𝖣 .ι i)
(Top.mono_iff_injective _).mpr (D.ι_injective _)
instance
Top.glue_data.ι_mono
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.mono_iff_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
image_inter (i j : D.J) : set.range (𝖣 .ι i) ∩ set.range (𝖣 .ι j) = set.range (D.f i j ≫ 𝖣 .ι _)
begin ext x, split, { rintro ⟨⟨x₁, eq₁⟩, ⟨x₂, eq₂⟩⟩, obtain (⟨⟨⟩⟩|⟨y,e₁,e₂⟩) := (D.ι_eq_iff_rel _ _ _ _).mp (eq₁.trans eq₂.symm), { exact ⟨inv (D.f i i) x₁, by simp [eq₁]⟩ }, { dsimp only at *, substs e₁ eq₁, exact ⟨y, by simp⟩ } }, { rintro ⟨x, hx⟩, exact ⟨⟨D.f i j x, hx⟩, ⟨D.f j i (D.t _ _ x),...
lemma
Top.glue_data.image_inter
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preimage_range (i j : D.J) : 𝖣 .ι j ⁻¹' (set.range (𝖣 .ι i)) = set.range (D.f j i)
by rw [← set.preimage_image_eq (set.range (D.f j i)) (D.ι_injective j), ← set.image_univ, ← set.image_univ, ←set.image_comp, ←coe_comp, set.image_univ,set.image_univ, ← image_inter, set.preimage_range_inter]
lemma
Top.glue_data.preimage_range
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "set.image_univ", "set.preimage_image_eq", "set.preimage_range_inter", "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preimage_image_eq_image (i j : D.J) (U : set (𝖣 .U i)) : 𝖣 .ι j ⁻¹' (𝖣 .ι i '' U) = D.f _ _ '' ((D.t j i ≫ D.f _ _) ⁻¹' U)
begin have : D.f _ _ ⁻¹' (𝖣 .ι j ⁻¹' (𝖣 .ι i '' U)) = (D.t j i ≫ D.f _ _) ⁻¹' U, { ext x, conv_rhs { rw ← set.preimage_image_eq U (D.ι_injective _) }, generalize : 𝖣 .ι i '' U = U', simp }, rw [← this, set.image_preimage_eq_inter_range], symmetry, apply set.inter_eq_self_of_subset_left, rw ← ...
lemma
Top.glue_data.preimage_image_eq_image
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "set.image_preimage_eq_inter_range", "set.image_subset_range", "set.inter_eq_self_of_subset_left", "set.preimage_image_eq", "set.preimage_mono" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
preimage_image_eq_image' (i j : D.J) (U : set (𝖣 .U i)) : 𝖣 .ι j ⁻¹' (𝖣 .ι i '' U) = (D.t i j ≫ D.f _ _) '' ((D.f _ _) ⁻¹' U)
begin convert D.preimage_image_eq_image i j U using 1, rw [coe_comp, coe_comp, ← set.image_image], congr' 1, rw [← set.eq_preimage_iff_image_eq, set.preimage_preimage], change _ = (D.t i j ≫ D.t j i ≫ _) ⁻¹' _, rw 𝖣 .t_inv_assoc, rw ← is_iso_iff_bijective, apply (forget Top).map_is_iso end
lemma
Top.glue_data.preimage_image_eq_image'
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top", "set.eq_preimage_iff_image_eq", "set.image_image", "set.preimage_preimage" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_image_open (i : D.J) (U : opens (𝖣 .U i)) : is_open (𝖣 .ι i '' U)
begin rw is_open_iff, intro j, rw preimage_image_eq_image, apply (D.f_open _ _).is_open_map, apply (D.t j i ≫ D.f i j).continuous_to_fun.is_open_preimage, exact U.is_open end
lemma
Top.glue_data.open_image_open
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "is_open", "is_open_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_open_embedding (i : D.J) : open_embedding (𝖣 .ι i)
open_embedding_of_continuous_injective_open (𝖣 .ι i).continuous_to_fun (D.ι_injective i) (λ U h, D.open_image_open i ⟨U, h⟩)
lemma
Top.glue_data.ι_open_embedding
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "open_embedding", "open_embedding_of_continuous_injective_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_core
{J : Type u} (U : J → Top.{u}) (V : Π i, J → opens (U i)) (t : Π i j, (opens.to_Top _).obj (V i j) ⟶ (opens.to_Top _).obj (V j i)) (V_id : ∀ i, V i i = ⊤) (t_id : ∀ i, ⇑(t i i) = id) (t_inter : ∀ ⦃i j⦄ k (x : V i j), ↑x ∈ V i k → @coe (V j i) (U j) _ (t i j x) ∈ V j k) (cocycle : ∀ i j k (x : V i j) (h : ↑x ∈ V i k), ...
structure
Top.glue_data.mk_core
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[]
A family of gluing data consists of 1. An index type `J` 2. A bundled topological space `U i` for each `i : J`. 3. An open set `V i j ⊆ U i` for each `i j : J`. 4. A transition map `t i j : V i j ⟶ V j i` for each `i j : ι`. such that 6. `V i i = U i`. 7. `t i i` is the identity. 8. For each `x ∈ V i j ∩ V i k`, `t i j...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_core.t_inv (h : mk_core) (i j : h.J) (x : h.V j i) : h.t i j ((h.t j i) x) = x
begin have := h.cocycle j i j x _, rw h.t_id at this, convert subtype.eq this, { ext, refl }, all_goals { rw h.V_id, trivial } end
lemma
Top.glue_data.mk_core.t_inv
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_core.t' (h : mk_core.{u}) (i j k : h.J) : pullback (h.V i j).inclusion (h.V i k).inclusion ⟶ pullback (h.V j k).inclusion (h.V j i).inclusion
begin refine (pullback_iso_prod_subtype _ _).hom ≫ ⟨_, _⟩ ≫ (pullback_iso_prod_subtype _ _).inv, { intro x, refine ⟨⟨⟨(h.t i j x.1.1).1, _⟩, h.t i j x.1.1⟩, rfl⟩, rcases x with ⟨⟨⟨x, hx⟩, ⟨x', hx'⟩⟩, (rfl : x = x')⟩, exact h.t_inter _ ⟨x, hx⟩ hx' }, continuity, end
def
Top.glue_data.mk_core.t'
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "continuity" ]
(Implementation) the restricted transition map to be fed into `glue_data`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk' (h : mk_core.{u}) : Top.glue_data
{ J := h.J, U := h.U, V := λ i, (opens.to_Top _).obj (h.V i.1 i.2), f := λ i j, (h.V i j).inclusion , f_id := λ i, (h.V_id i).symm ▸ is_iso.of_iso (opens.inclusion_top_iso (h.U i)), f_open := λ (i j : h.J), (h.V i j).open_embedding, t := h.t, t_id := λ i, by { ext, rw h.t_id, refl }, t' := h.t', t_fac...
def
Top.glue_data.mk'
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.comp_app", "Top.glue_data", "Top.id_app", "continuous_map.coe_mk", "mk'", "open_embedding", "prod.mk.inj_iff", "subtype.coe_mk", "subtype.mk_eq_mk", "subtype.val_eq_coe" ]
This is a constructor of `Top.glue_data` whose arguments are in terms of elements and intersections rather than subobjects and pullbacks. Please refer to `Top.glue_data.mk_core` for details.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_open_subsets : Top.glue_data.{u}
mk'.{u} { J := J, U := λ i, (opens.to_Top $ Top.of α).obj (U i), V := λ i j, (opens.map $ opens.inclusion _).obj (U j), t := λ i j, ⟨λ x, ⟨⟨x.1.1, x.2⟩, x.1.2⟩, by continuity⟩, V_id := λ i, by { ext, cases U i, simp }, t_id := λ i, by { ext, refl }, t_inter := λ i j k x hx, hx, cocycle := λ i j k x h, rfl...
def
Top.glue_data.of_open_subsets
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.of" ]
We may construct a glue data from a family of open sets.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
from_open_subsets_glue : (of_open_subsets U).to_glue_data.glued ⟶ Top.of α
multicoequalizer.desc _ _ (λ x, opens.inclusion _) (by { rintro ⟨i, j⟩, ext x, refl })
def
Top.glue_data.from_open_subsets_glue
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.of" ]
The canonical map from the glue of a family of open subsets `α` into `α`. This map is an open embedding (`from_open_subsets_glue_open_embedding`), and its range is `⋃ i, (U i : set α)` (`range_from_open_subsets_glue`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ι_from_open_subsets_glue (i : J) : (of_open_subsets U).to_glue_data.ι i ≫ from_open_subsets_glue U = opens.inclusion _
multicoequalizer.π_desc _ _ _ _ _
lemma
Top.glue_data.ι_from_open_subsets_glue
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
from_open_subsets_glue_injective : function.injective (from_open_subsets_glue U)
begin intros x y e, obtain ⟨i, ⟨x, hx⟩, rfl⟩ := (of_open_subsets U).ι_jointly_surjective x, obtain ⟨j, ⟨y, hy⟩, rfl⟩ := (of_open_subsets U).ι_jointly_surjective y, rw [ι_from_open_subsets_glue_apply, ι_from_open_subsets_glue_apply] at e, change x = y at e, subst e, rw (of_open_subsets U).ι_eq_iff_rel, r...
lemma
Top.glue_data.from_open_subsets_glue_injective
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
from_open_subsets_glue_is_open_map : is_open_map (from_open_subsets_glue U)
begin intros s hs, rw (of_open_subsets U).is_open_iff at hs, rw is_open_iff_forall_mem_open, rintros _ ⟨x, hx, rfl⟩, obtain ⟨i, ⟨x, hx'⟩, rfl⟩ := (of_open_subsets U).ι_jointly_surjective x, use from_open_subsets_glue U '' s ∩ set.range (@opens.inclusion (Top.of α) (U i)), use set.inter_subset_left _ _, ...
lemma
Top.glue_data.from_open_subsets_glue_is_open_map
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "Top.of", "is_open_iff_forall_mem_open", "is_open_map", "set.image_preimage_eq_inter_range", "set.inter_subset_left", "set.mem_range_self", "set.preimage_comp", "set.preimage_image_eq", "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
from_open_subsets_glue_open_embedding : open_embedding (from_open_subsets_glue U)
open_embedding_of_continuous_injective_open (continuous_map.continuous_to_fun _) (from_open_subsets_glue_injective U) (from_open_subsets_glue_is_open_map U)
lemma
Top.glue_data.from_open_subsets_glue_open_embedding
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "open_embedding", "open_embedding_of_continuous_injective_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_from_open_subsets_glue : set.range (from_open_subsets_glue U) = ⋃ i, (U i : set α)
begin ext, split, { rintro ⟨x, rfl⟩, obtain ⟨i, ⟨x, hx'⟩, rfl⟩ := (of_open_subsets U).ι_jointly_surjective x, rw ι_from_open_subsets_glue_apply, exact set.subset_Union _ i hx' }, { rintro ⟨_, ⟨i, rfl⟩, hx⟩, refine ⟨(of_open_subsets U).to_glue_data.ι i ⟨x, hx⟩, ι_from_open_subsets_glue_apply _ _ ...
lemma
Top.glue_data.range_from_open_subsets_glue
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "set.range", "set.subset_Union" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
open_cover_glue_homeo (h : (⋃ i, (U i : set α)) = set.univ) : (of_open_subsets U).to_glue_data.glued ≃ₜ α
homeomorph.homeomorph_of_continuous_open (equiv.of_bijective (from_open_subsets_glue U) ⟨from_open_subsets_glue_injective U, set.range_iff_surjective.mp ((range_from_open_subsets_glue U).symm ▸ h)⟩) (from_open_subsets_glue U).2 (from_open_subsets_glue_is_open_map U)
def
Top.glue_data.open_cover_glue_homeo
topology
src/topology/gluing.lean
[ "category_theory.glue_data", "category_theory.concrete_category.elementwise", "topology.category.Top.limits.pullbacks", "topology.category.Top.opens" ]
[ "equiv.of_bijective", "homeomorph.homeomorph_of_continuous_open" ]
The gluing of an open cover is homeomomorphic to the original space.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ (s : set α) : Prop
∃T : set (set α), (∀t ∈ T, is_open t) ∧ T.countable ∧ s = (⋂₀ T)
def
is_Gδ
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_open" ]
A Gδ set is a countable intersection of open sets.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_open.is_Gδ {s : set α} (h : is_open s) : is_Gδ s
⟨{s}, by simp [h], countable_singleton _, (set.sInter_singleton _).symm⟩
lemma
is_open.is_Gδ
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_open", "set.sInter_singleton" ]
An open set is a Gδ set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_empty : is_Gδ (∅ : set α)
is_open_empty.is_Gδ
lemma
is_Gδ_empty
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_univ : is_Gδ (univ : set α)
is_open_univ.is_Gδ
lemma
is_Gδ_univ
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_bInter_of_open {I : set ι} (hI : I.countable) {f : ι → set α} (hf : ∀i ∈ I, is_open (f i)) : is_Gδ (⋂i∈I, f i)
⟨f '' I, by rwa ball_image_iff, hI.image _, by rw sInter_image⟩
lemma
is_Gδ_bInter_of_open
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_Inter_of_open [encodable ι] {f : ι → set α} (hf : ∀i, is_open (f i)) : is_Gδ (⋂i, f i)
⟨range f, by rwa forall_range_iff, countable_range _, by rw sInter_range⟩
lemma
is_Gδ_Inter_of_open
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "encodable", "is_Gδ", "is_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_Inter [encodable ι] {s : ι → set α} (hs : ∀ i, is_Gδ (s i)) : is_Gδ (⋂ i, s i)
begin choose T hTo hTc hTs using hs, obtain rfl : s = λ i, ⋂₀ T i := funext hTs, refine ⟨⋃ i, T i, _, countable_Union hTc, (sInter_Union _).symm⟩, simpa [@forall_swap ι] using hTo end
lemma
is_Gδ_Inter
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "encodable", "forall_swap", "is_Gδ" ]
The intersection of an encodable family of Gδ sets is a Gδ set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_bInter {s : set ι} (hs : s.countable) {t : Π i ∈ s, set α} (ht : ∀ i ∈ s, is_Gδ (t i ‹_›)) : is_Gδ (⋂ i ∈ s, t i ‹_›)
begin rw [bInter_eq_Inter], haveI := hs.to_encodable, exact is_Gδ_Inter (λ x, ht x x.2) end
lemma
is_Gδ_bInter
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_Gδ_Inter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_sInter {S : set (set α)} (h : ∀s∈S, is_Gδ s) (hS : S.countable) : is_Gδ (⋂₀ S)
by simpa only [sInter_eq_bInter] using is_Gδ_bInter hS h
lemma
is_Gδ_sInter
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_Gδ_bInter" ]
A countable intersection of Gδ sets is a Gδ set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ.inter {s t : set α} (hs : is_Gδ s) (ht : is_Gδ t) : is_Gδ (s ∩ t)
by { rw inter_eq_Inter, exact is_Gδ_Inter (bool.forall_bool.2 ⟨ht, hs⟩) }
lemma
is_Gδ.inter
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_Gδ_Inter" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ.union {s t : set α} (hs : is_Gδ s) (ht : is_Gδ t) : is_Gδ (s ∪ t)
begin rcases hs with ⟨S, Sopen, Scount, rfl⟩, rcases ht with ⟨T, Topen, Tcount, rfl⟩, rw [sInter_union_sInter], apply is_Gδ_bInter_of_open (Scount.prod Tcount), rintros ⟨a, b⟩ ⟨ha, hb⟩, exact (Sopen a ha).union (Topen b hb) end
lemma
is_Gδ.union
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_Gδ_bInter_of_open" ]
The union of two Gδ sets is a Gδ set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_bUnion {s : set ι} (hs : s.finite) {f : ι → set α} (h : ∀ i ∈ s, is_Gδ (f i)) : is_Gδ (⋃ i ∈ s, f i)
begin refine finite.induction_on hs (by simp) _ h, simp only [ball_insert_iff, bUnion_insert], exact λ a s _ _ ihs H, H.1.union (ihs H.2) end
lemma
is_Gδ_bUnion
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ" ]
The union of finitely many Gδ sets is a Gδ set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_closed.is_Gδ {α} [uniform_space α] [is_countably_generated (𝓤 α)] {s : set α} (hs : is_closed s) : is_Gδ s
begin rcases (@uniformity_has_basis_open α _).exists_antitone_subbasis with ⟨U, hUo, hU, -⟩, rw [← hs.closure_eq, ← hU.bInter_bUnion_ball], refine is_Gδ_bInter (to_countable _) (λ n hn, is_open.is_Gδ _), exact is_open_bUnion (λ x hx, uniform_space.is_open_ball _ (hUo _).2) end
lemma
is_closed.is_Gδ
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_Gδ_bInter", "is_closed", "is_open.is_Gδ", "is_open_bUnion", "uniform_space", "uniform_space.is_open_ball", "uniformity_has_basis_open" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_compl_singleton (a : α) : is_Gδ ({a}ᶜ : set α)
is_open_compl_singleton.is_Gδ
lemma
is_Gδ_compl_singleton
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set.countable.is_Gδ_compl {s : set α} (hs : s.countable) : is_Gδ sᶜ
begin rw [← bUnion_of_singleton s, compl_Union₂], exact is_Gδ_bInter hs (λ x _, is_Gδ_compl_singleton x) end
lemma
set.countable.is_Gδ_compl
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_Gδ_bInter", "is_Gδ_compl_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set.finite.is_Gδ_compl {s : set α} (hs : s.finite) : is_Gδ sᶜ
hs.countable.is_Gδ_compl
lemma
set.finite.is_Gδ_compl
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set.subsingleton.is_Gδ_compl {s : set α} (hs : s.subsingleton) : is_Gδ sᶜ
hs.finite.is_Gδ_compl
lemma
set.subsingleton.is_Gδ_compl
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
finset.is_Gδ_compl (s : finset α) : is_Gδ (sᶜ : set α)
s.finite_to_set.is_Gδ_compl
lemma
finset.is_Gδ_compl
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "finset", "is_Gδ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_singleton (a : α) : is_Gδ ({a} : set α)
begin rcases (nhds_basis_opens a).exists_antitone_subbasis with ⟨U, hU, h_basis⟩, rw [← bInter_basis_nhds h_basis.to_has_basis], exact is_Gδ_bInter (to_countable _) (λ n hn, (hU n).2.is_Gδ), end
lemma
is_Gδ_singleton
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "bInter_basis_nhds", "is_Gδ", "is_Gδ_bInter", "nhds_basis_opens" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
set.finite.is_Gδ {s : set α} (hs : s.finite) : is_Gδ s
finite.induction_on hs is_Gδ_empty $ λ a s _ _ hs, (is_Gδ_singleton a).union hs
lemma
set.finite.is_Gδ
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "is_Gδ", "is_Gδ_empty", "is_Gδ_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_Gδ_set_of_continuous_at [uniform_space β] [is_countably_generated (𝓤 β)] (f : α → β) : is_Gδ {x | continuous_at f x}
begin obtain ⟨U, hUo, hU⟩ := (@uniformity_has_basis_open_symmetric β _).exists_antitone_subbasis, simp only [uniform.continuous_at_iff_prod, nhds_prod_eq], simp only [(nhds_basis_opens _).prod_self.tendsto_iff hU.to_has_basis, forall_prop_of_true, set_of_forall, id], refine is_Gδ_Inter (λ k, is_open.is_Gδ $...
lemma
is_Gδ_set_of_continuous_at
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "continuous_at", "forall_prop_of_true", "is_Gδ", "is_Gδ_Inter", "is_open.is_Gδ", "is_open.mem_nhds", "nhds_basis_opens", "nhds_prod_eq", "uniform.continuous_at_iff_prod", "uniform_space", "uniformity_has_basis_open_symmetric" ]
The set of points where a function is continuous is a Gδ set.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
residual (α : Type*) [topological_space α] : filter α
filter.countable_generate {t | is_open t ∧ dense t}
def
residual
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "dense", "filter", "filter.countable_generate", "is_open", "topological_space" ]
A set `s` is called *residual* if it includes a countable intersection of dense open sets.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
countable_Inter_filter_residual : countable_Inter_filter (residual α)
by rw [residual]; apply_instance
instance
countable_Inter_filter_residual
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "countable_Inter_filter", "residual" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
residual_of_dense_open {s : set α} (ho : is_open s) (hd : dense s) : s ∈ residual α
countable_generate_sets.basic ⟨ho, hd⟩
lemma
residual_of_dense_open
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "dense", "is_open", "residual" ]
Dense open sets are residual.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
residual_of_dense_Gδ {s : set α} (ho : is_Gδ s) (hd : dense s) : s ∈ residual α
begin rcases ho with ⟨T, To, Tct, rfl⟩, exact (countable_sInter_mem Tct).mpr (λ t tT, residual_of_dense_open (To t tT) (hd.mono (sInter_subset_of_mem tT))), end
lemma
residual_of_dense_Gδ
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "countable_sInter_mem", "dense", "is_Gδ", "residual", "residual_of_dense_open" ]
Dense Gδ sets are residual.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_residual_iff {s : set α} : s ∈ residual α ↔ ∃ (S : set (set α)), (∀ t ∈ S, is_open t) ∧ (∀ t ∈ S, dense t) ∧ S.countable ∧ ⋂₀ S ⊆ s
mem_countable_generate_iff.trans $ by simp_rw [subset_def, mem_set_of, forall_and_distrib, and_assoc]
lemma
mem_residual_iff
topology
src/topology/G_delta.lean
[ "topology.uniform_space.basic", "topology.separation", "order.filter.countable_Inter" ]
[ "dense", "forall_and_distrib", "is_open", "residual" ]
A set is residual iff it includes a countable intersection of dense open sets.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homeomorph (α : Type*) (β : Type*) [topological_space α] [topological_space β] extends α ≃ β
(continuous_to_fun : continuous to_fun . tactic.interactive.continuity') (continuous_inv_fun : continuous inv_fun . tactic.interactive.continuity')
structure
homeomorph
topology
src/topology/homeomorph.lean
[ "logic.equiv.fin", "topology.dense_embedding", "topology.support" ]
[ "continuous", "inv_fun", "tactic.interactive.continuity'", "topological_space" ]
Homeomorphism between `α` and `β`, also called topological isomorphism
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
homeomorph_mk_coe (a : equiv α β) (b c) : ((homeomorph.mk a b c) : α → β) = a
rfl
lemma
homeomorph.homeomorph_mk_coe
topology
src/topology/homeomorph.lean
[ "logic.equiv.fin", "topology.dense_embedding", "topology.support" ]
[ "equiv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
symm (h : α ≃ₜ β) : β ≃ₜ α
{ continuous_to_fun := h.continuous_inv_fun, continuous_inv_fun := h.continuous_to_fun, to_equiv := h.to_equiv.symm }
def
homeomorph.symm
topology
src/topology/homeomorph.lean
[ "logic.equiv.fin", "topology.dense_embedding", "topology.support" ]
[]
Inverse of a homeomorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
simps.apply (h : α ≃ₜ β) : α → β
h
def
homeomorph.simps.apply
topology
src/topology/homeomorph.lean
[ "logic.equiv.fin", "topology.dense_embedding", "topology.support" ]
[]
See Note [custom simps projection]. We need to specify this projection explicitly in this case, because it is a composition of multiple projections.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83