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gc_closureOperator (S : Set T) : gc.closureOperator S = hull T (kernel S)
by simp only [toDual_sInf, GaloisConnection.closureOperator_apply, ofDual_sSup] rw [← preimage_comp, ← OrderDual.toDual_symm_eq, Equiv.symm_comp_self, preimage_id_eq, id_eq]
lemma
PrimitiveSpectrum.gc_closureOperator
Topology.Order
Mathlib/Topology/Order/HullKernel.lean
[]
[ "Equiv.symm_comp_self", "OrderDual.toDual_symm_eq", "Set", "ofDual_sSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
OrderGenerates
∀ (a : α), ∃ (S : Set T), a = kernel S
def
PrimitiveSpectrum.OrderGenerates
Topology.Order
Mathlib/Topology/Order/HullKernel.lean
[]
[ "Set" ]
`T` order generates `α` if, for every `a` in `α`, there exists a subset of `T` such that `a` is the `kernel` of `S`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
gi (hG : OrderGenerates T) : GaloisInsertion (α := Set T) (β := αᵒᵈ) (OrderDual.toDual ∘ kernel) (hull T ∘ OrderDual.ofDual)
gc.toGaloisInsertion fun a ↦ by obtain ⟨S, rfl⟩ := hG a rw [OrderDual.le_toDual, kernel, kernel] exact sInf_le_sInf <| image_val_mono fun c hcS => by rw [hull, mem_preimage, mem_Ici] exact sInf_le (mem_image_of_mem Subtype.val hcS)
def
PrimitiveSpectrum.gi
Topology.Order
Mathlib/Topology/Order/HullKernel.lean
[]
[ "GaloisInsertion", "OrderDual.le_toDual", "OrderDual.ofDual", "OrderDual.toDual", "Set" ]
When `T` is order generating, the `kernel` and the `hull` form a Galois insertion
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
kernel_hull (hG : OrderGenerates T) (a : α) : kernel (hull T a) = a
by conv_rhs => rw [← OrderDual.ofDual_toDual a, ← (gi hG).l_u_eq a] rfl
lemma
PrimitiveSpectrum.kernel_hull
Topology.Order
Mathlib/Topology/Order/HullKernel.lean
[]
[ "OrderDual.ofDual_toDual" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
hull_kernel_of_isClosed [TopologicalSpace α] [IsLower α] (hT : ∀ p ∈ T, InfPrime p) (hG : OrderGenerates T) {C : Set T} (h : IsClosed C) : hull T (kernel C) = C
by obtain ⟨a, ha⟩ := (isClosed_iff hT).mp h rw [ha, kernel_hull hG]
lemma
PrimitiveSpectrum.hull_kernel_of_isClosed
Topology.Order
Mathlib/Topology/Order/HullKernel.lean
[]
[ "InfPrime", "IsClosed", "Set", "TopologicalSpace" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
closedsGC_closureOperator [TopologicalSpace α] [IsLower α] (hT : ∀ p ∈ T, InfPrime p) (hG : OrderGenerates T) (S : Set T) : (TopologicalSpace.Closeds.gc (α := T)).closureOperator S = hull T (kernel S)
by simp only [GaloisConnection.closureOperator_apply, Closeds.coe_closure, closure, le_antisymm_iff] constructor · exact fun ⦃a⦄ a ↦ a (hull T (kernel S)) ⟨(isClosed_iff hT).mpr ⟨kernel S, rfl⟩, image_subset_iff.mp (fun _ hbS => sInf_le hbS)⟩ · simp_rw [le_eq_subset, subset_sInter_iff] intro R hR ...
lemma
PrimitiveSpectrum.closedsGC_closureOperator
Topology.Order
Mathlib/Topology/Order/HullKernel.lean
[]
[ "ClosureOperator.monotone", "InfPrime", "Set", "TopologicalSpace", "TopologicalSpace.Closeds.gc", "closure", "le_antisymm_iff" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_univ₂ [PreconnectedSpace X] {a b : X} {f g : X → α} (hf : Continuous f) (hg : Continuous g) (ha : f a ≤ g a) (hb : g b ≤ f b) : ∃ x, f x = g x
by obtain ⟨x, _, hfg, hgf⟩ : (univ ∩ { x | f x ≤ g x ∧ g x ≤ f x }).Nonempty := isPreconnected_closed_iff.1 PreconnectedSpace.isPreconnected_univ _ _ (isClosed_le hf hg) (isClosed_le hg hf) (fun _ _ => le_total _ _) ⟨a, trivial, ha⟩ ⟨b, trivial, hb⟩ exact ⟨x, le_antisymm hfg hgf⟩
theorem
intermediate_value_univ₂
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "PreconnectedSpace", "isClosed_le", "le_antisymm", "le_total" ]
Intermediate value theorem for two functions: if `f` and `g` are two continuous functions on a preconnected space and `f a ≤ g a` and `g b ≤ f b`, then for some `x` we have `f x = g x`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_univ₂_eventually₁ [PreconnectedSpace X] {a : X} {l : Filter X} [NeBot l] {f g : X → α} (hf : Continuous f) (hg : Continuous g) (ha : f a ≤ g a) (he : g ≤ᶠ[l] f) : ∃ x, f x = g x
let ⟨_, h⟩ := he.exists; intermediate_value_univ₂ hf hg ha h
theorem
intermediate_value_univ₂_eventually₁
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "Filter", "PreconnectedSpace", "intermediate_value_univ₂" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_univ₂_eventually₂ [PreconnectedSpace X] {l₁ l₂ : Filter X} [NeBot l₁] [NeBot l₂] {f g : X → α} (hf : Continuous f) (hg : Continuous g) (he₁ : f ≤ᶠ[l₁] g) (he₂ : g ≤ᶠ[l₂] f) : ∃ x, f x = g x
let ⟨_, h₁⟩ := he₁.exists let ⟨_, h₂⟩ := he₂.exists intermediate_value_univ₂ hf hg h₁ h₂
theorem
intermediate_value_univ₂_eventually₂
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "Filter", "PreconnectedSpace", "intermediate_value_univ₂" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value₂ {s : Set X} (hs : IsPreconnected s) {a b : X} (ha : a ∈ s) (hb : b ∈ s) {f g : X → α} (hf : ContinuousOn f s) (hg : ContinuousOn g s) (ha' : f a ≤ g a) (hb' : g b ≤ f b) : ∃ x ∈ s, f x = g x
let ⟨x, hx⟩ := @intermediate_value_univ₂ s α _ _ _ _ (Subtype.preconnectedSpace hs) ⟨a, ha⟩ ⟨b, hb⟩ _ _ (continuousOn_iff_continuous_restrict.1 hf) (continuousOn_iff_continuous_restrict.1 hg) ha' hb' ⟨x, x.2, hx⟩
theorem
IsPreconnected.intermediate_value₂
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected", "Set", "Subtype.preconnectedSpace", "intermediate_value_univ₂" ]
Intermediate value theorem for two functions: if `f` and `g` are two functions continuous on a preconnected set `s` and for some `a b ∈ s` we have `f a ≤ g a` and `g b ≤ f b`, then for some `x ∈ s` we have `f x = g x`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value₂_eventually₁ {s : Set X} (hs : IsPreconnected s) {a : X} {l : Filter X} (ha : a ∈ s) [NeBot l] (hl : l ≤ 𝓟 s) {f g : X → α} (hf : ContinuousOn f s) (hg : ContinuousOn g s) (ha' : f a ≤ g a) (he : g ≤ᶠ[l] f) : ∃ x ∈ s, f x = g x
by rw [continuousOn_iff_continuous_restrict] at hf hg obtain ⟨b, h⟩ := @intermediate_value_univ₂_eventually₁ _ _ _ _ _ _ (Subtype.preconnectedSpace hs) ⟨a, ha⟩ _ (comap_coe_neBot_of_le_principal hl) _ _ hf hg ha' (he.comap _) exact ⟨b, b.prop, h⟩
theorem
IsPreconnected.intermediate_value₂_eventually₁
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "Subtype.preconnectedSpace", "continuousOn_iff_continuous_restrict", "intermediate_value_univ₂_eventually₁" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value₂_eventually₂ {s : Set X} (hs : IsPreconnected s) {l₁ l₂ : Filter X} [NeBot l₁] [NeBot l₂] (hl₁ : l₁ ≤ 𝓟 s) (hl₂ : l₂ ≤ 𝓟 s) {f g : X → α} (hf : ContinuousOn f s) (hg : ContinuousOn g s) (he₁ : f ≤ᶠ[l₁] g) (he₂ : g ≤ᶠ[l₂] f) : ∃ x ∈ s, f x = g x
by rw [continuousOn_iff_continuous_restrict] at hf hg obtain ⟨b, h⟩ := @intermediate_value_univ₂_eventually₂ _ _ _ _ _ _ (Subtype.preconnectedSpace hs) _ _ (comap_coe_neBot_of_le_principal hl₁) (comap_coe_neBot_of_le_principal hl₂) _ _ hf hg (he₁.comap _) (he₂.comap _) exact ⟨b, b.prop, h⟩
theorem
IsPreconnected.intermediate_value₂_eventually₂
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "Subtype.preconnectedSpace", "continuousOn_iff_continuous_restrict", "intermediate_value_univ₂_eventually₂" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value {s : Set X} (hs : IsPreconnected s) {a b : X} (ha : a ∈ s) (hb : b ∈ s) {f : X → α} (hf : ContinuousOn f s) : Icc (f a) (f b) ⊆ f '' s
fun _x hx => hs.intermediate_value₂ ha hb hf continuousOn_const hx.1 hx.2
theorem
IsPreconnected.intermediate_value
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected", "Set", "continuousOn_const" ]
**Intermediate Value Theorem** for continuous functions on connected sets.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Ico {s : Set X} (hs : IsPreconnected s) {a : X} {l : Filter X} (ha : a ∈ s) [NeBot l] (hl : l ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) {v : α} (ht : Tendsto f l (𝓝 v)) : Ico (f a) v ⊆ f '' s
fun _ h => hs.intermediate_value₂_eventually₁ ha hl hf continuousOn_const h.1 (ht.eventually_const_le h.2)
theorem
IsPreconnected.intermediate_value_Ico
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Ioc {s : Set X} (hs : IsPreconnected s) {a : X} {l : Filter X} (ha : a ∈ s) [NeBot l] (hl : l ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) {v : α} (ht : Tendsto f l (𝓝 v)) : Ioc v (f a) ⊆ f '' s
fun _ h => (hs.intermediate_value₂_eventually₁ ha hl continuousOn_const hf h.2 (ht.eventually_le_const h.1)).imp fun _ h => h.imp_right Eq.symm
theorem
IsPreconnected.intermediate_value_Ioc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Ioo {s : Set X} (hs : IsPreconnected s) {l₁ l₂ : Filter X} [NeBot l₁] [NeBot l₂] (hl₁ : l₁ ≤ 𝓟 s) (hl₂ : l₂ ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) {v₁ v₂ : α} (ht₁ : Tendsto f l₁ (𝓝 v₁)) (ht₂ : Tendsto f l₂ (𝓝 v₂)) : Ioo v₁ v₂ ⊆ f '' s
fun _ h => hs.intermediate_value₂_eventually₂ hl₁ hl₂ hf continuousOn_const (ht₁.eventually_le_const h.1) (ht₂.eventually_const_le h.2)
theorem
IsPreconnected.intermediate_value_Ioo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Ici {s : Set X} (hs : IsPreconnected s) {a : X} {l : Filter X} (ha : a ∈ s) [NeBot l] (hl : l ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) (ht : Tendsto f l atTop) : Ici (f a) ⊆ f '' s
fun y h => hs.intermediate_value₂_eventually₁ ha hl hf continuousOn_const h (tendsto_atTop.1 ht y)
theorem
IsPreconnected.intermediate_value_Ici
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Iic {s : Set X} (hs : IsPreconnected s) {a : X} {l : Filter X} (ha : a ∈ s) [NeBot l] (hl : l ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) (ht : Tendsto f l atBot) : Iic (f a) ⊆ f '' s
fun y h => (hs.intermediate_value₂_eventually₁ ha hl continuousOn_const hf h (tendsto_atBot.1 ht y)).imp fun _ h => h.imp_right Eq.symm
theorem
IsPreconnected.intermediate_value_Iic
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Ioi {s : Set X} (hs : IsPreconnected s) {l₁ l₂ : Filter X} [NeBot l₁] [NeBot l₂] (hl₁ : l₁ ≤ 𝓟 s) (hl₂ : l₂ ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) {v : α} (ht₁ : Tendsto f l₁ (𝓝 v)) (ht₂ : Tendsto f l₂ atTop) : Ioi v ⊆ f '' s
fun y h => hs.intermediate_value₂_eventually₂ hl₁ hl₂ hf continuousOn_const (ht₁.eventually_le_const h) (ht₂.eventually_ge_atTop y)
theorem
IsPreconnected.intermediate_value_Ioi
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Iio {s : Set X} (hs : IsPreconnected s) {l₁ l₂ : Filter X} [NeBot l₁] [NeBot l₂] (hl₁ : l₁ ≤ 𝓟 s) (hl₂ : l₂ ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) {v : α} (ht₁ : Tendsto f l₁ atBot) (ht₂ : Tendsto f l₂ (𝓝 v)) : Iio v ⊆ f '' s
fun y h => hs.intermediate_value₂_eventually₂ hl₁ hl₂ hf continuousOn_const (ht₁.eventually_le_atBot y) (ht₂.eventually_const_le h)
theorem
IsPreconnected.intermediate_value_Iio
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.intermediate_value_Iii {s : Set X} (hs : IsPreconnected s) {l₁ l₂ : Filter X} [NeBot l₁] [NeBot l₂] (hl₁ : l₁ ≤ 𝓟 s) (hl₂ : l₂ ≤ 𝓟 s) {f : X → α} (hf : ContinuousOn f s) (ht₁ : Tendsto f l₁ atBot) (ht₂ : Tendsto f l₂ atTop) : univ ⊆ f '' s
fun y _ => hs.intermediate_value₂_eventually₂ hl₁ hl₂ hf continuousOn_const (ht₁.eventually_le_atBot y) (ht₂.eventually_ge_atTop y)
theorem
IsPreconnected.intermediate_value_Iii
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Filter", "IsPreconnected", "Set", "continuousOn_const" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_univ [PreconnectedSpace X] (a b : X) {f : X → α} (hf : Continuous f) : Icc (f a) (f b) ⊆ range f
fun _ hx => intermediate_value_univ₂ hf continuous_const hx.1 hx.2
theorem
intermediate_value_univ
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "PreconnectedSpace", "continuous_const", "intermediate_value_univ₂" ]
**Intermediate Value Theorem** for continuous functions on connected spaces.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
mem_range_of_exists_le_of_exists_ge [PreconnectedSpace X] {c : α} {f : X → α} (hf : Continuous f) (h₁ : ∃ a, f a ≤ c) (h₂ : ∃ b, c ≤ f b) : c ∈ range f
let ⟨a, ha⟩ := h₁; let ⟨b, hb⟩ := h₂; intermediate_value_univ a b hf ⟨ha, hb⟩
theorem
mem_range_of_exists_le_of_exists_ge
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "PreconnectedSpace", "intermediate_value_univ" ]
**Intermediate Value Theorem** for continuous functions on connected spaces.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.Icc_subset {s : Set α} (hs : IsPreconnected s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) : Icc a b ⊆ s
by simpa only [image_id] using! hs.intermediate_value ha hb continuousOn_id
theorem
IsPreconnected.Icc_subset
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "Set", "continuousOn_id" ]
If a preconnected set contains endpoints of an interval, then it includes the whole interval.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.ordConnected {s : Set α} (h : IsPreconnected s) : OrdConnected s
⟨fun _ hx _ hy => h.Icc_subset hx hy⟩
theorem
IsPreconnected.ordConnected
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsConnected.Icc_subset {s : Set α} (hs : IsConnected s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) : Icc a b ⊆ s
hs.2.Icc_subset ha hb
theorem
IsConnected.Icc_subset
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected", "Set" ]
If a preconnected set contains endpoints of an interval, then it includes the whole interval.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.eq_univ_of_unbounded {s : Set α} (hs : IsPreconnected s) (hb : ¬BddBelow s) (ha : ¬BddAbove s) : s = univ
by refine eq_univ_of_forall fun x => ?_ obtain ⟨y, ys, hy⟩ : ∃ y ∈ s, y < x := not_bddBelow_iff.1 hb x obtain ⟨z, zs, hz⟩ : ∃ z ∈ s, x < z := not_bddAbove_iff.1 ha x exact hs.Icc_subset ys zs ⟨le_of_lt hy, le_of_lt hz⟩
theorem
IsPreconnected.eq_univ_of_unbounded
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsPreconnected", "Set", "le_of_lt" ]
If a preconnected set in a linear order space is unbounded below and above, then it is the whole space.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
denselyOrdered_of_preconnectedSpace [LinearOrder α] [OrderTopology α] [PreconnectedSpace α] : DenselyOrdered α
where dense x y hxy := by suffices (Iio y ∩ Ioi x).Nonempty by grind [Set.inter_nonempty_iff_exists_left] exact nonempty_inter (isOpen_Iio' y) (isOpen_Ioi' x) (Set.Iio_union_Ioi_of_lt hxy) ⟨x, Set.mem_Iio.mpr hxy⟩ ⟨y, Set.mem_Ioi.mpr hxy⟩
theorem
denselyOrdered_of_preconnectedSpace
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "DenselyOrdered", "LinearOrder", "OrderTopology", "PreconnectedSpace", "Set.Iio_union_Ioi_of_lt", "Set.inter_nonempty_iff_exists_left", "isOpen_Ioi'", "nonempty_inter" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsConnected.Ioo_csInf_csSup_subset {s : Set α} (hs : IsConnected s) (hb : BddBelow s) (ha : BddAbove s) : Ioo (sInf s) (sSup s) ⊆ s
fun _x hx => let ⟨_y, ys, hy⟩ := (isGLB_lt_iff (isGLB_csInf hs.nonempty hb)).1 hx.1 let ⟨_z, zs, hz⟩ := (lt_isLUB_iff (isLUB_csSup hs.nonempty ha)).1 hx.2 hs.Icc_subset ys zs ⟨hy.le, hz.le⟩
theorem
IsConnected.Ioo_csInf_csSup_subset
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsConnected", "Set", "isLUB_csSup", "lt_isLUB_iff" ]
A bounded connected subset of a conditionally complete linear order includes the open interval `(Inf s, Sup s)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
eq_Icc_csInf_csSup_of_connected_bdd_closed {s : Set α} (hc : IsConnected s) (hb : BddBelow s) (ha : BddAbove s) (hcl : IsClosed s) : s = Icc (sInf s) (sSup s)
(subset_Icc_csInf_csSup hb ha).antisymm <| hc.Icc_subset (hcl.csInf_mem hc.nonempty hb) (hcl.csSup_mem hc.nonempty ha)
theorem
eq_Icc_csInf_csSup_of_connected_bdd_closed
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsClosed", "IsConnected", "Set", "antisymm", "subset_Icc_csInf_csSup" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.Ioi_csInf_subset {s : Set α} (hs : IsPreconnected s) (hb : BddBelow s) (ha : ¬BddAbove s) : Ioi (sInf s) ⊆ s
fun x hx => have sne : s.Nonempty := nonempty_of_not_bddAbove ha let ⟨_y, ys, hy⟩ : ∃ y ∈ s, y < x := (isGLB_lt_iff (isGLB_csInf sne hb)).1 hx let ⟨_z, zs, hz⟩ : ∃ z ∈ s, x < z := not_bddAbove_iff.1 ha x hs.Icc_subset ys zs ⟨hy.le, hz.le⟩
theorem
IsPreconnected.Ioi_csInf_subset
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsPreconnected", "Set", "nonempty_of_not_bddAbove" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.Iio_csSup_subset {s : Set α} (hs : IsPreconnected s) (hb : ¬BddBelow s) (ha : BddAbove s) : Iio (sSup s) ⊆ s
IsPreconnected.Ioi_csInf_subset (α := αᵒᵈ) hs ha hb
theorem
IsPreconnected.Iio_csSup_subset
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsPreconnected", "IsPreconnected.Ioi_csInf_subset", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsPreconnected.mem_intervals {s : Set α} (hs : IsPreconnected s) : s ∈ ({Icc (sInf s) (sSup s), Ico (sInf s) (sSup s), Ioc (sInf s) (sSup s), Ioo (sInf s) (sSup s), Ici (sInf s), Ioi (sInf s), Iic (sSup s), Iio (sSup s), univ, ∅} : Set (Set α))
by rcases s.eq_empty_or_nonempty with (rfl | hne) · apply_rules [Or.inr, mem_singleton] have hs' : IsConnected s := ⟨hne, hs⟩ by_cases hb : BddBelow s <;> by_cases ha : BddAbove s · refine mem_of_subset_of_mem ?_ <| mem_Icc_Ico_Ioc_Ioo_of_subset_of_subset (hs'.Ioo_csInf_csSup_subset hb ha) (subset_Icc_c...
theorem
IsPreconnected.mem_intervals
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsConnected", "IsPreconnected", "Set", "by_cases", "le_csSup", "subset_Icc_csInf_csSup" ]
A preconnected set in a conditionally complete linear order is either one of the intervals `[Inf s, Sup s]`, `[Inf s, Sup s)`, `(Inf s, Sup s]`, `(Inf s, Sup s)`, `[Inf s, +∞)`, `(Inf s, +∞)`, `(-∞, Sup s]`, `(-∞, Sup s)`, `(-∞, +∞)`, or `∅`. The converse statement requires `α` to be densely ordered.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
setOf_isPreconnected_subset_of_ordered : { s : Set α | IsPreconnected s } ⊆ -- bounded intervals (range (uncurry Icc) ∪ range (uncurry Ico) ∪ range (uncurry Ioc) ∪ range (uncurry Ioo)) ∪ -- unbounded intervals and `univ` (range Ici ∪ range Ioi ∪ range Iic ∪ range Iio ∪ {univ, ∅})
by intro s hs rcases hs.mem_intervals with (hs | hs | hs | hs | hs | hs | hs | hs | hs | hs) <;> rw [hs] <;> simp only [union_insert, union_singleton, mem_insert_iff, mem_union, mem_range, Prod.exists, uncurry_apply_pair, exists_apply_eq_apply, true_or, or_true, exists_apply_eq_apply2]
theorem
setOf_isPreconnected_subset_of_ordered
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "Set", "exists_apply_eq_apply2" ]
A preconnected set is either one of the intervals `Icc`, `Ico`, `Ioc`, `Ioo`, `Ici`, `Ioi`, `Iic`, `Iio`, or `univ`, or `∅`. The converse statement requires `α` to be densely ordered. Though one can represent `∅` as `(Inf ∅, Inf ∅)`, we include it into the list of possible cases to improve readability.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.mem_of_ge_of_forall_exists_gt {a b : α} {s : Set α} (hs : IsClosed (s ∩ Icc a b)) (ha : a ∈ s) (hab : a ≤ b) (hgt : ∀ x ∈ s ∩ Ico a b, (s ∩ Ioc x b).Nonempty) : b ∈ s
by let S := s ∩ Icc a b replace ha : a ∈ S := ⟨ha, left_mem_Icc.2 hab⟩ have Sbd : BddAbove S := ⟨b, fun z hz => hz.2.2⟩ let c := sSup (s ∩ Icc a b) have c_mem : c ∈ S := hs.csSup_mem ⟨_, ha⟩ Sbd have c_le : c ≤ b := csSup_le ⟨_, ha⟩ fun x hx => hx.2.2 rcases eq_or_lt_of_le c_le with hc | hc · exact hc ▸...
theorem
IsClosed.mem_of_ge_of_forall_exists_gt
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsClosed", "Set", "csSup_le", "eq_or_lt_of_le", "le_csSup", "le_of_lt", "le_trans", "not_lt_of_ge" ]
A "continuous induction principle" for a closed interval: if a set `s` meets `[a, b]` on a closed subset, contains `a`, and the set `s ∩ [a, b)` has no maximal point, then `b ∈ s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.Icc_subset_of_forall_exists_gt {a b : α} {s : Set α} (hs : IsClosed (s ∩ Icc a b)) (ha : a ∈ s) (hgt : ∀ x ∈ s ∩ Ico a b, ∀ y ∈ Ioi x, (s ∩ Ioc x y).Nonempty) : Icc a b ⊆ s
by intro y hy have : IsClosed (s ∩ Icc a y) := by suffices s ∩ Icc a y = s ∩ Icc a b ∩ Icc a y from this ▸ hs.inter isClosed_Icc grind [inter_assoc, inter_eq_self_of_subset_right, Icc_subset_Icc_right] exact IsClosed.mem_of_ge_of_forall_exists_gt this ha hy.1 fun x hx ↦ hgt x ⟨hx.1, Ico_subset_Ico_rig...
theorem
IsClosed.Icc_subset_of_forall_exists_gt
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsClosed", "IsClosed.mem_of_ge_of_forall_exists_gt", "Set", "isClosed_Icc" ]
A "continuous induction principle" for a closed interval: if a set `s` meets `[a, b]` on a closed subset, contains `a`, and for any `a ≤ x < y ≤ b`, `x ∈ s`, the set `s ∩ (x, y]` is not empty, then `[a, b] ⊆ s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.mem_of_ge_of_forall_exists_lt {a b : α} {s : Set α} (hs : IsClosed (s ∩ Icc a b)) (hb : b ∈ s) (hab : a ≤ b) (hgt : ∀ x ∈ s ∩ Ioc a b, (s ∩ Ico a x).Nonempty) : a ∈ s
by suffices OrderDual.toDual a ∈ ofDual ⁻¹' s by aesop have : IsClosed (OrderDual.ofDual ⁻¹' (s ∩ Icc a b)) := hs rw [preimage_inter, ← Icc_toDual] at this apply this.mem_of_ge_of_forall_exists_gt (by simp_all) (by simp_all) (fun x hx ↦ ?_) rw [Ico_toDual, ← preimage_inter, ← Equiv.image_symm_eq_preimage, mem...
theorem
IsClosed.mem_of_ge_of_forall_exists_lt
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Equiv.image_symm_eq_preimage", "IsClosed", "OrderDual.ofDual", "OrderDual.toDual", "Set" ]
A "continuous induction principle" for a closed interval: if a set `s` meets `[a, b]` on a closed subset, contains `b`, and the set `s ∩ (a, b]` has no minimal point, then `a ∈ s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.Icc_subset_of_forall_exists_lt {a b : α} {s : Set α} (hs : IsClosed (s ∩ Icc a b)) (hb : b ∈ s) (hgt : ∀ x ∈ s ∩ Ioc a b, ∀ y ∈ Iio x, (s ∩ Ico y x).Nonempty) : Icc a b ⊆ s
by intro y hy have : IsClosed (s ∩ Icc y b) := by suffices s ∩ Icc y b = s ∩ Icc a b ∩ Icc y b from this ▸ hs.inter isClosed_Icc grind [Icc_subset_Icc_left, inter_eq_self_of_subset_right, inter_assoc] exact IsClosed.mem_of_ge_of_forall_exists_lt this hb hy.2 fun x hx ↦ hgt x ⟨hx.1, Ioc_subset_Ioc_left...
theorem
IsClosed.Icc_subset_of_forall_exists_lt
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsClosed", "IsClosed.mem_of_ge_of_forall_exists_lt", "Set", "isClosed_Icc" ]
A "continuous induction principle" for a closed interval: if a set `s` meets `[a, b]` on a closed subset, contains `b`, and for any `a ≤ y < x ≤ b`, `x ∈ s`, the set `s ∩ [y, x)` is not empty, then `[a, b] ⊆ s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.Icc_subset_of_forall_mem_nhdsGT_of_Icc_subset {a b : α} {s : Set α} (hs : IsClosed (s ∩ Icc a b)) (ha : a ∈ s) (h : ∀ t ∈ Ico a b, Icc a t ⊆ s → s ∈ 𝓝[>] t) : Icc a b ⊆ s
by rcases lt_or_ge b a with hab | hab · simp_all set A := {t ∈ Icc a b | Icc a t ⊆ s} have a_mem : a ∈ A := ⟨left_mem_Icc.mpr hab, by simp [ha]⟩ have bdd_A : BddAbove A := ⟨b, fun t ht ↦ ht.1.2⟩ set t₁ := sSup A have t₁_mem : t₁ ∈ Icc a b := ⟨le_csSup bdd_A a_mem, csSup_le ⟨a, a_mem⟩ (fun t ht ↦ ht.1.2)⟩ ...
lemma
IsClosed.Icc_subset_of_forall_mem_nhdsGT_of_Icc_subset
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BddAbove", "IsClosed", "Set", "closure", "csSup_le", "csSup_mem_closure", "eq_of_le_of_not_lt", "exists_between", "le_csSup", "le_or_gt", "lt_csSup_iff", "lt_min", "lt_or_ge", "mem_nhdsGT_iff_exists_Ioo_subset'", "min_le_left", "min_le_right" ]
A "continuous induction principle" for a closed interval: if a set `s` meets `[a, b]` on a closed subset, contains `a`, and for any `x ∈ [a, b)` such that `[a, x]` is included in `s`, the set `s` includes some open neighborhood of `x` within `(x, +∞)`, then `[a, b] ⊆ s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
IsClosed.Icc_subset_of_forall_mem_nhdsWithin {a b : α} {s : Set α} (hs : IsClosed (s ∩ Icc a b)) (ha : a ∈ s) (hgt : ∀ x ∈ s ∩ Ico a b, s ∈ 𝓝[>] x) : Icc a b ⊆ s
hs.Icc_subset_of_forall_mem_nhdsGT_of_Icc_subset ha (fun _t ht h't ↦ hgt _ ⟨h't ⟨ht.1, le_rfl⟩, ht⟩)
theorem
IsClosed.Icc_subset_of_forall_mem_nhdsWithin
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsClosed", "Set" ]
A "continuous induction principle" for a closed interval: if a set `s` meets `[a, b]` on a closed subset, contains `a`, and for any `x ∈ s ∩ [a, b)` the set `s` includes some open neighborhood of `x` within `(x, +∞)`, then `[a, b] ⊆ s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Icc_aux (x y : α) (s t : Set α) (hxy : x ≤ y) (hs : IsClosed s) (ht : IsClosed t) (hab : Icc a b ⊆ s ∪ t) (hx : x ∈ Icc a b ∩ s) (hy : y ∈ Icc a b ∩ t) : (Icc a b ∩ (s ∩ t)).Nonempty
by have xyab : Icc x y ⊆ Icc a b := Icc_subset_Icc hx.1.1 hy.1.2 by_contra hst suffices Icc x y ⊆ s from hst ⟨y, xyab <| right_mem_Icc.2 hxy, this <| right_mem_Icc.2 hxy, hy.2⟩ apply (IsClosed.inter hs isClosed_Icc).Icc_subset_of_forall_mem_nhdsWithin hx.2 rintro z ⟨zs, hz⟩ have zt : z ∈ tᶜ := fun zt =>...
theorem
isPreconnected_Icc_aux
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsClosed", "IsClosed.inter", "Set", "isClosed_Icc", "le_of_lt" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Icc : IsPreconnected (Icc a b)
isPreconnected_closed_iff.2 (by rintro s t hs ht hab ⟨x, hx⟩ ⟨y, hy⟩ -- This used to use `wlog`, but it was causing timeouts. rcases le_total x y with h | h · exact isPreconnected_Icc_aux x y s t h hs ht hab hx hy · rw [inter_comm s t] rw [union_comm s t] at hab exact i...
theorem
isPreconnected_Icc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "isPreconnected_Icc_aux", "le_total" ]
A closed interval in a densely ordered conditionally complete linear order is preconnected.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_uIcc : IsPreconnected ([[a, b]])
isPreconnected_Icc
theorem
isPreconnected_uIcc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "isPreconnected_Icc" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Set.OrdConnected.isPreconnected {s : Set α} (h : s.OrdConnected) : IsPreconnected s
isPreconnected_of_forall_pair fun x hx y hy => ⟨[[x, y]], h.uIcc_subset hx hy, left_mem_uIcc, right_mem_uIcc, isPreconnected_uIcc⟩
theorem
Set.OrdConnected.isPreconnected
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "Set", "isPreconnected_of_forall_pair" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_iff_ordConnected {s : Set α} : IsPreconnected s ↔ OrdConnected s
⟨IsPreconnected.ordConnected, Set.OrdConnected.isPreconnected⟩
theorem
isPreconnected_iff_ordConnected
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "Set" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Ici : IsPreconnected (Ici a)
ordConnected_Ici.isPreconnected
theorem
isPreconnected_Ici
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Iic : IsPreconnected (Iic a)
ordConnected_Iic.isPreconnected
theorem
isPreconnected_Iic
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Iio : IsPreconnected (Iio a)
ordConnected_Iio.isPreconnected
theorem
isPreconnected_Iio
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Ioi : IsPreconnected (Ioi a)
ordConnected_Ioi.isPreconnected
theorem
isPreconnected_Ioi
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Ioo : IsPreconnected (Ioo a b)
ordConnected_Ioo.isPreconnected
theorem
isPreconnected_Ioo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_uIoo : IsPreconnected (uIoo a b)
isPreconnected_Ioo
theorem
isPreconnected_uIoo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "isPreconnected_Ioo" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Ioc : IsPreconnected (Ioc a b)
ordConnected_Ioc.isPreconnected
theorem
isPreconnected_Ioc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_uIoc : IsPreconnected (uIoc a b)
isPreconnected_Ioc
theorem
isPreconnected_uIoc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "isPreconnected_Ioc" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isPreconnected_Ico : IsPreconnected (Ico a b)
ordConnected_Ico.isPreconnected
theorem
isPreconnected_Ico
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Ici : IsConnected (Ici a)
⟨nonempty_Ici, isPreconnected_Ici⟩
theorem
isConnected_Ici
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Iic : IsConnected (Iic a)
⟨nonempty_Iic, isPreconnected_Iic⟩
theorem
isConnected_Iic
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Ioi [NoMaxOrder α] : IsConnected (Ioi a)
⟨nonempty_Ioi, isPreconnected_Ioi⟩
theorem
isConnected_Ioi
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected", "NoMaxOrder" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Iio [NoMinOrder α] : IsConnected (Iio a)
⟨nonempty_Iio, isPreconnected_Iio⟩
theorem
isConnected_Iio
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected", "NoMinOrder" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Icc (h : a ≤ b) : IsConnected (Icc a b)
⟨nonempty_Icc.2 h, isPreconnected_Icc⟩
theorem
isConnected_Icc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Ioo (h : a < b) : IsConnected (Ioo a b)
⟨nonempty_Ioo.2 h, isPreconnected_Ioo⟩
theorem
isConnected_Ioo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_uIoo (h : a ≠ b) : IsConnected (uIoo a b)
⟨nonempty_uIoo.2 h, isPreconnected_uIoo⟩
theorem
isConnected_uIoo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Ioc (h : a < b) : IsConnected (Ioc a b)
⟨nonempty_Ioc.2 h, isPreconnected_Ioc⟩
theorem
isConnected_Ioc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_uIoc (h : a ≠ b) : IsConnected (uIoc a b)
⟨nonempty_uIoc.2 h, isPreconnected_uIoc⟩
theorem
isConnected_uIoc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isConnected_Ico (h : a < b) : IsConnected (Ico a b)
⟨nonempty_Ico.2 h, isPreconnected_Ico⟩
theorem
isConnected_Ico
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsConnected" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
setOf_isPreconnected_eq_of_ordered : { s : Set α | IsPreconnected s } = -- bounded intervals range (uncurry Icc) ∪ range (uncurry Ico) ∪ range (uncurry Ioc) ∪ range (uncurry Ioo) ∪ -- unbounded intervals and `univ` (range Ici ∪ range Ioi ∪ range Iic ∪ range Iio ∪ {univ, ∅})
by refine Subset.antisymm setOf_isPreconnected_subset_of_ordered ?_ simp only [subset_def, forall_mem_range, uncurry, or_imp, forall_and, mem_union, mem_setOf_eq, insert_eq, mem_singleton_iff, forall_eq, forall_true_iff, and_true, isPreconnected_Icc, isPreconnected_Ico, isPreconnected_Ioc, isPreconnected_Io...
theorem
setOf_isPreconnected_eq_of_ordered
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsPreconnected", "Set", "forall_true_iff", "isPreconnected_Icc", "isPreconnected_Ici", "isPreconnected_Ico", "isPreconnected_Iic", "isPreconnected_Iio", "isPreconnected_Ioc", "isPreconnected_Ioi", "isPreconnected_Ioo", "isPreconnected_empty", "setOf_isPreconnected_subset_of_ordered" ]
In a dense conditionally complete linear order, the set of preconnected sets is exactly the set of the intervals `Icc`, `Ico`, `Ioc`, `Ioo`, `Ici`, `Ioi`, `Iic`, `Iio`, `(-∞, +∞)`, or `∅`. Though one can represent `∅` as `(sInf s, sInf s)`, we include it into the list of possible cases to improve readability.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isTotallyDisconnected_iff_lt {s : Set α} : IsTotallyDisconnected s ↔ ∀ x ∈ s, ∀ y ∈ s, x < y → ∃ z ∉ s, z ∈ Ioo x y
by simp only [IsTotallyDisconnected, isPreconnected_iff_ordConnected, ← not_nontrivial_iff, nontrivial_iff_exists_lt, not_exists, not_and] refine ⟨fun h x hx y hy hxy ↦ ?_, fun h t hts ht x hx y hy hxy ↦ ?_⟩ · simp_rw [← not_ordConnected_inter_Icc_iff hx hy] exact fun hs ↦ h _ inter_subset_left hs _ ⟨hx, ...
lemma
isTotallyDisconnected_iff_lt
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "IsTotallyDisconnected", "Set", "isPreconnected_iff_ordConnected", "le_rfl" ]
This lemma characterizes when a subset `s` of a densely ordered conditionally complete linear order is totally disconnected with respect to the order topology: between any two distinct points of `s` must lie a point not in `s`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Icc {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Icc (f a) (f b) ⊆ f '' Icc a b
isPreconnected_Icc.intermediate_value (left_mem_Icc.2 hab) (right_mem_Icc.2 hab) hf
theorem
intermediate_value_Icc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn" ]
**Intermediate Value Theorem** for continuous functions on closed intervals, case `f a ≤ t ≤ f b`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Icc' {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Icc (f b) (f a) ⊆ f '' Icc a b
isPreconnected_Icc.intermediate_value (right_mem_Icc.2 hab) (left_mem_Icc.2 hab) hf
theorem
intermediate_value_Icc'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn" ]
**Intermediate Value Theorem** for continuous functions on closed intervals, case `f a ≥ t ≥ f b`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_uIcc {a b : α} {f : α → δ} (hf : ContinuousOn f [[a, b]]) : [[f a, f b]] ⊆ f '' uIcc a b
by cases le_total (f a) (f b) <;> simp [*, isPreconnected_uIcc.intermediate_value]
theorem
intermediate_value_uIcc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "le_total" ]
**Intermediate Value Theorem** for continuous functions on closed intervals, unordered case.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
exists_mem_uIcc_isFixedPt {a b : α} {f : α → α} (hf : ContinuousOn f (uIcc a b)) (ha : a ≤ f a) (hb : f b ≤ b) : ∃ c ∈ [[a, b]], IsFixedPt f c
isPreconnected_uIcc.intermediate_value₂ right_mem_uIcc left_mem_uIcc hf continuousOn_id hb ha
theorem
exists_mem_uIcc_isFixedPt
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "continuousOn_id" ]
If `f : α → α` is continuous on `[[a, b]]`, `a ≤ f a`, and `f b ≤ b`, then `f` has a fixed point on `[[a, b]]`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
exists_mem_Icc_isFixedPt {a b : α} {f : α → α} (hf : ContinuousOn f (Icc a b)) (hle : a ≤ b) (ha : a ≤ f a) (hb : f b ≤ b) : ∃ c ∈ Icc a b, IsFixedPt f c
isPreconnected_Icc.intermediate_value₂ (right_mem_Icc.2 hle) (left_mem_Icc.2 hle) hf continuousOn_id hb ha
theorem
exists_mem_Icc_isFixedPt
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "continuousOn_id" ]
If `f : α → α` is continuous on `[a, b]`, `a ≤ b`, `a ≤ f a`, and `f b ≤ b`, then `f` has a fixed point on `[a, b]`. In particular, if `[a, b]` is forward-invariant under `f`, then `f` has a fixed point on `[a, b]`, see `exists_mem_Icc_isFixedPt_of_mapsTo`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
exists_mem_Icc_isFixedPt_of_mapsTo {a b : α} {f : α → α} (hf : ContinuousOn f (Icc a b)) (hle : a ≤ b) (hmaps : MapsTo f (Icc a b) (Icc a b)) : ∃ c ∈ Icc a b, IsFixedPt f c
exists_mem_Icc_isFixedPt hf hle (hmaps <| left_mem_Icc.2 hle).1 (hmaps <| right_mem_Icc.2 hle).2
theorem
exists_mem_Icc_isFixedPt_of_mapsTo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "exists_mem_Icc_isFixedPt" ]
If a closed interval is forward-invariant under a continuous map `f : α → α`, then this map has a fixed point on this interval.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Ico {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Ico (f a) (f b) ⊆ f '' Ico a b
Or.elim (eq_or_lt_of_le hab) (fun he _ h => absurd h.2 (not_lt_of_ge (he ▸ h.1))) fun hlt => @IsPreconnected.intermediate_value_Ico _ _ _ _ _ _ _ isPreconnected_Ico _ _ ⟨refl a, hlt⟩ (right_nhdsWithin_Ico_neBot hlt) inf_le_right _ (hf.mono Ico_subset_Icc_self) _ ((hf.continuousWithinAt ⟨hab, refl b⟩).mo...
theorem
intermediate_value_Ico
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected.intermediate_value_Ico", "eq_or_lt_of_le", "isPreconnected_Ico", "not_lt_of_ge", "refl", "right_nhdsWithin_Ico_neBot" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Ico' {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Ioc (f b) (f a) ⊆ f '' Ico a b
Or.elim (eq_or_lt_of_le hab) (fun he _ h => absurd h.1 (not_lt_of_ge (he ▸ h.2))) fun hlt => @IsPreconnected.intermediate_value_Ioc _ _ _ _ _ _ _ isPreconnected_Ico _ _ ⟨refl a, hlt⟩ (right_nhdsWithin_Ico_neBot hlt) inf_le_right _ (hf.mono Ico_subset_Icc_self) _ ((hf.continuousWithinAt ⟨hab, refl b⟩).mo...
theorem
intermediate_value_Ico'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected.intermediate_value_Ioc", "eq_or_lt_of_le", "isPreconnected_Ico", "not_lt_of_ge", "refl", "right_nhdsWithin_Ico_neBot" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Ioc {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Ioc (f a) (f b) ⊆ f '' Ioc a b
Or.elim (eq_or_lt_of_le hab) (fun he _ h => absurd h.2 (not_le_of_gt (he ▸ h.1))) fun hlt => @IsPreconnected.intermediate_value_Ioc _ _ _ _ _ _ _ isPreconnected_Ioc _ _ ⟨hlt, refl b⟩ (left_nhdsWithin_Ioc_neBot hlt) inf_le_right _ (hf.mono Ioc_subset_Icc_self) _ ((hf.continuousWithinAt ⟨refl a, hab⟩).mon...
theorem
intermediate_value_Ioc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected.intermediate_value_Ioc", "eq_or_lt_of_le", "isPreconnected_Ioc", "left_nhdsWithin_Ioc_neBot", "not_le_of_gt", "refl" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Ioc' {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Ico (f b) (f a) ⊆ f '' Ioc a b
Or.elim (eq_or_lt_of_le hab) (fun he _ h => absurd h.1 (not_le_of_gt (he ▸ h.2))) fun hlt => @IsPreconnected.intermediate_value_Ico _ _ _ _ _ _ _ isPreconnected_Ioc _ _ ⟨hlt, refl b⟩ (left_nhdsWithin_Ioc_neBot hlt) inf_le_right _ (hf.mono Ioc_subset_Icc_self) _ ((hf.continuousWithinAt ⟨refl a, hab⟩).mon...
theorem
intermediate_value_Ioc'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected.intermediate_value_Ico", "eq_or_lt_of_le", "isPreconnected_Ioc", "left_nhdsWithin_Ioc_neBot", "not_le_of_gt", "refl" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Ioo {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Ioo (f a) (f b) ⊆ f '' Ioo a b
Or.elim (eq_or_lt_of_le hab) (fun he _ h => absurd h.2 (not_lt_of_gt (he ▸ h.1))) fun hlt => @IsPreconnected.intermediate_value_Ioo _ _ _ _ _ _ _ isPreconnected_Ioo _ _ (left_nhdsWithin_Ioo_neBot hlt) (right_nhdsWithin_Ioo_neBot hlt) inf_le_right inf_le_right _ (hf.mono Ioo_subset_Icc_self) _ _ ((...
theorem
intermediate_value_Ioo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected.intermediate_value_Ioo", "eq_or_lt_of_le", "isPreconnected_Ioo", "left_nhdsWithin_Ioo_neBot", "refl", "right_nhdsWithin_Ioo_neBot" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
intermediate_value_Ioo' {a b : α} (hab : a ≤ b) {f : α → δ} (hf : ContinuousOn f (Icc a b)) : Ioo (f b) (f a) ⊆ f '' Ioo a b
Or.elim (eq_or_lt_of_le hab) (fun he _ h => absurd h.1 (not_lt_of_gt (he ▸ h.2))) fun hlt => @IsPreconnected.intermediate_value_Ioo _ _ _ _ _ _ _ isPreconnected_Ioo _ _ (right_nhdsWithin_Ioo_neBot hlt) (left_nhdsWithin_Ioo_neBot hlt) inf_le_right inf_le_right _ (hf.mono Ioo_subset_Icc_self) _ _ ((...
theorem
intermediate_value_Ioo'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "IsPreconnected.intermediate_value_Ioo", "eq_or_lt_of_le", "isPreconnected_Ioo", "left_nhdsWithin_Ioo_neBot", "refl", "right_nhdsWithin_Ioo_neBot" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.surjOn_Icc {s : Set α} [hs : OrdConnected s] {f : α → δ} (hf : ContinuousOn f s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) : SurjOn f s (Icc (f a) (f b))
hs.isPreconnected.intermediate_value ha hb hf
theorem
ContinuousOn.surjOn_Icc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Set" ]
**Intermediate value theorem**: if `f` is continuous on an order-connected set `s` and `a`, `b` are two points of this set, then `f` sends `s` to a superset of `Icc (f a) (f b)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.surjOn_uIcc {s : Set α} [hs : OrdConnected s] {f : α → δ} (hf : ContinuousOn f s) {a b : α} (ha : a ∈ s) (hb : b ∈ s) : SurjOn f s (uIcc (f a) (f b))
by rcases le_total (f a) (f b) with hab | hab <;> simp [hf.surjOn_Icc, *]
theorem
ContinuousOn.surjOn_uIcc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Set", "le_total" ]
**Intermediate value theorem**: if `f` is continuous on an order-connected set `s` and `a`, `b` are two points of this set, then `f` sends `s` to a superset of `[f a, f b]`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Continuous.surjective {f : α → δ} (hf : Continuous f) (h_top : Tendsto f atTop atTop) (h_bot : Tendsto f atBot atBot) : Function.Surjective f
fun p => mem_range_of_exists_le_of_exists_ge hf (h_bot.eventually (eventually_le_atBot p)).exists (h_top.eventually (eventually_ge_atTop p)).exists
theorem
Continuous.surjective
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "mem_range_of_exists_le_of_exists_ge" ]
A continuous function which tends to `Filter.atTop` along `Filter.atTop` and to `Filter.atBot` along `Filter.atBot` is surjective.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Continuous.surjective' {f : α → δ} (hf : Continuous f) (h_top : Tendsto f atBot atTop) (h_bot : Tendsto f atTop atBot) : Function.Surjective f
Continuous.surjective (α := αᵒᵈ) hf h_top h_bot
theorem
Continuous.surjective'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "Continuous.surjective" ]
A continuous function which tends to `Filter.atBot` along `Filter.atTop` and to `Filter.atTop` along `Filter.atBot` is surjective.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.surjOn_of_tendsto {f : α → δ} {s : Set α} [OrdConnected s] (hs : s.Nonempty) (hf : ContinuousOn f s) (hbot : Tendsto (fun x : s => f x) atBot atBot) (htop : Tendsto (fun x : s => f x) atTop atTop) : SurjOn f s univ
haveI := Classical.inhabited_of_nonempty hs.to_subtype surjOn_iff_surjective.2 <| hf.restrict.surjective htop hbot
theorem
ContinuousOn.surjOn_of_tendsto
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "Set" ]
If a function `f : α → β` is continuous on a nonempty interval `s`, its restriction to `s` tends to `Filter.atBot : Filter β` along `Filter.atBot : Filter ↥s` and tends to `Filter.atTop : Filter β` along `Filter.atTop : Filter ↥s`, then the restriction of `f` to `s` is surjective. We formulate the conclusion as `Functi...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.surjOn_of_tendsto' {f : α → δ} {s : Set α} [OrdConnected s] (hs : s.Nonempty) (hf : ContinuousOn f s) (hbot : Tendsto (fun x : s => f x) atBot atTop) (htop : Tendsto (fun x : s => f x) atTop atBot) : SurjOn f s univ
ContinuousOn.surjOn_of_tendsto (δ := δᵒᵈ) hs hf hbot htop
theorem
ContinuousOn.surjOn_of_tendsto'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "ContinuousOn.surjOn_of_tendsto", "Set" ]
If a function `f : α → β` is continuous on a nonempty interval `s`, its restriction to `s` tends to `Filter.atTop : Filter β` along `Filter.atBot : Filter ↥s` and tends to `Filter.atBot : Filter β` along `Filter.atTop : Filter ↥s`, then the restriction of `f` to `s` is surjective. We formulate the conclusion as `Functi...
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Continuous.strictMono_of_inj_boundedOrder [BoundedOrder α] {f : α → δ} (hf_c : Continuous f) (hf : f ⊥ ≤ f ⊤) (hf_i : Injective f) : StrictMono f
by intro a b hab by_contra! h have H : f b < f a := lt_of_le_of_ne h <| hf_i.ne hab.ne' by_cases! ha : f a ≤ f ⊥ · obtain ⟨u, hu⟩ := intermediate_value_Ioc le_top hf_c.continuousOn ⟨H.trans_le ha, hf⟩ have : u = ⊥ := hf_i hu.2 simp_all · by_cases! hb : f ⊥ < f b · obtain ⟨u, hu⟩ := intermediate_...
theorem
Continuous.strictMono_of_inj_boundedOrder
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BoundedOrder", "Continuous", "StrictMono", "intermediate_value_Ioc", "intermediate_value_Ioo", "intermediate_value_Ioo'", "le_top", "lt_of_le_of_ne" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Continuous.strictAnti_of_inj_boundedOrder [BoundedOrder α] {f : α → δ} (hf_c : Continuous f) (hf : f ⊤ ≤ f ⊥) (hf_i : Injective f) : StrictAnti f
hf_c.strictMono_of_inj_boundedOrder (δ := δᵒᵈ) hf hf_i
theorem
Continuous.strictAnti_of_inj_boundedOrder
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BoundedOrder", "Continuous", "StrictAnti" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Continuous.strictMono_of_inj_boundedOrder' [BoundedOrder α] {f : α → δ} (hf_c : Continuous f) (hf_i : Injective f) : StrictMono f ∨ StrictAnti f
(le_total (f ⊥) (f ⊤)).imp (hf_c.strictMono_of_inj_boundedOrder · hf_i) (hf_c.strictAnti_of_inj_boundedOrder · hf_i)
theorem
Continuous.strictMono_of_inj_boundedOrder'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "BoundedOrder", "Continuous", "StrictAnti", "StrictMono", "le_total" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Continuous.strictMonoOn_of_inj_rigidity {f : α → δ} (hf_c : Continuous f) (hf_i : Injective f) {a b : α} (hab : a < b) (hf_mono : StrictMonoOn f (Icc a b)) : StrictMono f
by intro x y hxy let s := min a x let t := max b y have hsa : s ≤ a := min_le_left a x have hbt : b ≤ t := le_max_left b y have hf_mono_st : StrictMonoOn f (Icc s t) ∨ StrictAntiOn f (Icc s t) := by have : Fact (s ≤ t) := ⟨hsa.trans <| hbt.trans' hab.le⟩ have := Continuous.strictMono_of_inj_boundedO...
theorem
Continuous.strictMonoOn_of_inj_rigidity
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "Continuous.strictMono_of_inj_boundedOrder'", "Fact", "IsAntichain", "IsAntichain.of_strictMonoOn_antitoneOn", "Set.restrict", "StrictAntiOn", "StrictAntiOn.mono", "StrictMono", "StrictMonoOn", "StrictMonoOn.mono", "le_of_lt", "min_le_left", "min_le_right" ]
Suppose `α` is equipped with a conditionally complete linear dense order and `f : α → δ` is continuous and injective. Then `f` is strictly monotone (increasing) if it is strictly monotone (increasing) on some closed interval `[a, b]`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.strictMonoOn_of_injOn_Icc {a b : α} {f : α → δ} (hab : a ≤ b) (hfab : f a ≤ f b) (hf_c : ContinuousOn f (Icc a b)) (hf_i : InjOn f (Icc a b)) : StrictMonoOn f (Icc a b)
by have : Fact (a ≤ b) := ⟨hab⟩ refine StrictMono.of_restrict ?_ set g : Icc a b → δ := Set.restrict (Icc a b) f have hgab : g ⊥ ≤ g ⊤ := by aesop exact Continuous.strictMono_of_inj_boundedOrder (f := g) hf_c.restrict hgab hf_i.injective
theorem
ContinuousOn.strictMonoOn_of_injOn_Icc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous.strictMono_of_inj_boundedOrder", "ContinuousOn", "Fact", "Set.restrict", "StrictMonoOn" ]
Suppose `f : [a, b] → δ` is continuous and injective. Then `f` is strictly monotone (increasing) if `f(a) ≤ f(b)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.strictAntiOn_of_injOn_Icc {a b : α} {f : α → δ} (hab : a ≤ b) (hfab : f b ≤ f a) (hf_c : ContinuousOn f (Icc a b)) (hf_i : InjOn f (Icc a b)) : StrictAntiOn f (Icc a b)
ContinuousOn.strictMonoOn_of_injOn_Icc (δ := δᵒᵈ) hab hfab hf_c hf_i
theorem
ContinuousOn.strictAntiOn_of_injOn_Icc
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "ContinuousOn.strictMonoOn_of_injOn_Icc", "StrictAntiOn" ]
Suppose `f : [a, b] → δ` is continuous and injective. Then `f` is strictly antitone (decreasing) if `f(b) ≤ f(a)`.
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.strictMonoOn_of_injOn_Icc' {a b : α} {f : α → δ} (hab : a ≤ b) (hf_c : ContinuousOn f (Icc a b)) (hf_i : InjOn f (Icc a b)) : StrictMonoOn f (Icc a b) ∨ StrictAntiOn f (Icc a b)
(le_total (f a) (f b)).imp (ContinuousOn.strictMonoOn_of_injOn_Icc hab · hf_c hf_i) (ContinuousOn.strictAntiOn_of_injOn_Icc hab · hf_c hf_i)
theorem
ContinuousOn.strictMonoOn_of_injOn_Icc'
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "ContinuousOn", "ContinuousOn.strictAntiOn_of_injOn_Icc", "ContinuousOn.strictMonoOn_of_injOn_Icc", "StrictAntiOn", "StrictMonoOn", "le_total" ]
Suppose `f : [a, b] → δ` is continuous and injective. Then `f` is strictly monotone or antitone (increasing or decreasing).
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
Continuous.strictMono_of_inj {f : α → δ} (hf_c : Continuous f) (hf_i : Injective f) : StrictMono f ∨ StrictAnti f
by have H {c d : α} (hcd : c < d) : StrictMono f ∨ StrictAnti f := (hf_c.continuousOn.strictMonoOn_of_injOn_Icc' hcd.le hf_i.injOn).imp (hf_c.strictMonoOn_of_inj_rigidity hf_i hcd) (hf_c.strictMonoOn_of_inj_rigidity (δ := δᵒᵈ) hf_i hcd) cases subsingleton_or_nontrivial α with | inl h => exact Or.i...
theorem
Continuous.strictMono_of_inj
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous", "StrictAnti", "StrictMono", "Subsingleton.strictMono", "exists_pair_lt", "subsingleton_or_nontrivial" ]
Suppose `α` is equipped with a conditionally complete linear dense order and `f : α → δ` is continuous and injective. Then `f` is strictly monotone or antitone (increasing or decreasing).
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
ContinuousOn.strictMonoOn_of_injOn_Ioo {a b : α} {f : α → δ} (hab : a < b) (hf_c : ContinuousOn f (Ioo a b)) (hf_i : InjOn f (Ioo a b)) : StrictMonoOn f (Ioo a b) ∨ StrictAntiOn f (Ioo a b)
by haveI : Inhabited (Ioo a b) := Classical.inhabited_of_nonempty (nonempty_Ioo_subtype hab) let g : Ioo a b → δ := Set.restrict (Ioo a b) f have : StrictMono g ∨ StrictAnti g := Continuous.strictMono_of_inj hf_c.restrict hf_i.injective exact this.imp strictMono_restrict.mp strictAntiOn_iff_strictAnti.mpr
theorem
ContinuousOn.strictMonoOn_of_injOn_Ioo
Topology.Order
Mathlib/Topology/Order/IntermediateValue.lean
[]
[ "Continuous.strictMono_of_inj", "ContinuousOn", "Set.restrict", "StrictAnti", "StrictAntiOn", "StrictMono", "StrictMonoOn" ]
Every continuous injective `f : (a, b) → δ` is strictly monotone or antitone (increasing or decreasing).
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isLocallyClosed_Icc [Preorder X] [OrderClosedTopology X] : IsLocallyClosed (Set.Icc a b)
isClosed_Icc.isLocallyClosed
theorem
isLocallyClosed_Icc
Topology.Order
Mathlib/Topology/Order/IsLocallyClosed.lean
[]
[ "IsLocallyClosed", "OrderClosedTopology", "Preorder", "Set.Icc" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isLocallyClosed_Ioo [LinearOrder X] [OrderClosedTopology X] : IsLocallyClosed (Set.Ioo a b)
isOpen_Ioo.isLocallyClosed
theorem
isLocallyClosed_Ioo
Topology.Order
Mathlib/Topology/Order/IsLocallyClosed.lean
[]
[ "IsLocallyClosed", "LinearOrder", "OrderClosedTopology", "Set.Ioo" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isLocallyClosed_Ici [Preorder X] [ClosedIciTopology X] : IsLocallyClosed (Set.Ici a)
isClosed_Ici.isLocallyClosed
theorem
isLocallyClosed_Ici
Topology.Order
Mathlib/Topology/Order/IsLocallyClosed.lean
[]
[ "ClosedIciTopology", "IsLocallyClosed", "Preorder" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isLocallyClosed_Iic [Preorder X] [ClosedIicTopology X] : IsLocallyClosed (Set.Iic a)
isClosed_Iic.isLocallyClosed
theorem
isLocallyClosed_Iic
Topology.Order
Mathlib/Topology/Order/IsLocallyClosed.lean
[]
[ "ClosedIicTopology", "IsLocallyClosed", "Preorder", "Set.Iic" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isLocallyClosed_Ioi [LinearOrder X] [ClosedIicTopology X] : IsLocallyClosed (Set.Ioi a)
isOpen_Ioi.isLocallyClosed
theorem
isLocallyClosed_Ioi
Topology.Order
Mathlib/Topology/Order/IsLocallyClosed.lean
[]
[ "ClosedIicTopology", "IsLocallyClosed", "LinearOrder" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isLocallyClosed_Iio [LinearOrder X] [ClosedIciTopology X] : IsLocallyClosed (Set.Iio a)
isOpen_Iio.isLocallyClosed
theorem
isLocallyClosed_Iio
Topology.Order
Mathlib/Topology/Order/IsLocallyClosed.lean
[]
[ "ClosedIciTopology", "IsLocallyClosed", "LinearOrder", "Set.Iio" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319
isLocallyClosed_Ioc [LinearOrder X] [ClosedIicTopology X] : IsLocallyClosed (Set.Ioc a b)
by rw [← Set.Iic_inter_Ioi] exact isLocallyClosed_Iic.inter isLocallyClosed_Ioi
theorem
isLocallyClosed_Ioc
Topology.Order
Mathlib/Topology/Order/IsLocallyClosed.lean
[]
[ "ClosedIicTopology", "IsLocallyClosed", "LinearOrder", "Set.Ioc", "isLocallyClosed_Ioi" ]
https://github.com/leanprover-community/mathlib4
b9f14353520df73472ae3825fb53f86559a01319