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import Mathlib.Order.CompleteLattice import Mathlib.Order.Cover import Mathlib.Order.Iterate import Mathlib.Order.WellFounded #align_import order.succ_pred.basic from "leanprover-community/mathlib"@"0111834459f5d7400215223ea95ae38a1265a907" open Function OrderDual Set variable {α β : Type*} @[ext] class SuccOr...
Mathlib/Order/SuccPred/Basic.lean
279
281
theorem succ_lt_succ_iff_of_not_isMax (ha : ¬IsMax a) (hb : ¬IsMax b) : succ a < succ b ↔ a < b := by
rw [lt_succ_iff_of_not_isMax hb, succ_le_iff_of_not_isMax ha]
995
import Mathlib.Order.CompleteLattice import Mathlib.Order.Cover import Mathlib.Order.Iterate import Mathlib.Order.WellFounded #align_import order.succ_pred.basic from "leanprover-community/mathlib"@"0111834459f5d7400215223ea95ae38a1265a907" open Function OrderDual Set variable {α β : Type*} @[ext] class SuccOr...
Mathlib/Order/SuccPred/Basic.lean
284
286
theorem succ_le_succ_iff_of_not_isMax (ha : ¬IsMax a) (hb : ¬IsMax b) : succ a ≤ succ b ↔ a ≤ b := by
rw [succ_le_iff_of_not_isMax ha, lt_succ_iff_of_not_isMax hb]
995
import Mathlib.Order.CompleteLattice import Mathlib.Order.Cover import Mathlib.Order.Iterate import Mathlib.Order.WellFounded #align_import order.succ_pred.basic from "leanprover-community/mathlib"@"0111834459f5d7400215223ea95ae38a1265a907" open Function OrderDual Set variable {α β : Type*} @[ext] class SuccOr...
Mathlib/Order/SuccPred/Basic.lean
290
295
theorem succ_le_succ (h : a ≤ b) : succ a ≤ succ b := by
by_cases hb : IsMax b · by_cases hba : b ≤ a · exact (hb <| hba.trans <| le_succ _).trans (le_succ _) · exact succ_le_of_lt ((h.lt_of_not_le hba).trans_le <| le_succ b) · rwa [succ_le_iff_of_not_isMax fun ha => hb <| ha.mono h, lt_succ_iff_of_not_isMax hb]
995
import Mathlib.Order.Interval.Set.Disjoint import Mathlib.Order.SuccPred.Basic #align_import data.set.intervals.monotone from "leanprover-community/mathlib"@"4d06b17aea8cf2e220f0b0aa46cd0231593c5c97" open Set section SuccOrder open Order variable {α β : Type*} [PartialOrder α]
Mathlib/Order/Interval/Set/Monotone.lean
203
218
theorem StrictMonoOn.Iic_id_le [SuccOrder α] [IsSuccArchimedean α] [OrderBot α] {n : α} {φ : α → α} (hφ : StrictMonoOn φ (Set.Iic n)) : ∀ m ≤ n, m ≤ φ m := by
revert hφ refine Succ.rec_bot (fun n => StrictMonoOn φ (Set.Iic n) → ∀ m ≤ n, m ≤ φ m) (fun _ _ hm => hm.trans bot_le) ?_ _ rintro k ih hφ m hm by_cases hk : IsMax k · rw [succ_eq_iff_isMax.2 hk] at hm exact ih (hφ.mono <| Iic_subset_Iic.2 (le_succ _)) _ hm obtain rfl | h := le_succ_iff_eq_or...
996
import Mathlib.Order.Interval.Set.Disjoint import Mathlib.Order.SuccPred.Basic #align_import data.set.intervals.monotone from "leanprover-community/mathlib"@"4d06b17aea8cf2e220f0b0aa46cd0231593c5c97" open Set section SuccOrder open Order variable {α β : Type*} [PartialOrder α] theorem StrictMonoOn.Iic_id_le [...
Mathlib/Order/Interval/Set/Monotone.lean
230
253
theorem strictMonoOn_Iic_of_lt_succ [SuccOrder α] [IsSuccArchimedean α] {n : α} (hψ : ∀ m, m < n → ψ m < ψ (succ m)) : StrictMonoOn ψ (Set.Iic n) := by
intro x hx y hy hxy obtain ⟨i, rfl⟩ := hxy.le.exists_succ_iterate induction' i with k ih · simp at hxy cases' k with k · exact hψ _ (lt_of_lt_of_le hxy hy) rw [Set.mem_Iic] at * simp only [Function.iterate_succ', Function.comp_apply] at ih hxy hy ⊢ by_cases hmax : IsMax (succ^[k] x) · rw [succ_eq_i...
996
import Mathlib.Data.Set.Pairwise.Basic import Mathlib.Data.Set.Lattice import Mathlib.Order.SuccPred.Basic #align_import order.succ_pred.interval_succ from "leanprover-community/mathlib"@"c227d107bbada5d0d9d20287e3282c0a7f1651a0" open Set Order variable {α β : Type*} [LinearOrder α] namespace Monotone
Mathlib/Order/SuccPred/IntervalSucc.lean
38
48
theorem biUnion_Ico_Ioc_map_succ [SuccOrder α] [IsSuccArchimedean α] [LinearOrder β] {f : α → β} (hf : Monotone f) (m n : α) : ⋃ i ∈ Ico m n, Ioc (f i) (f (succ i)) = Ioc (f m) (f n) := by
rcases le_total n m with hnm | hmn · rw [Ico_eq_empty_of_le hnm, Ioc_eq_empty_of_le (hf hnm), biUnion_empty] · refine Succ.rec ?_ ?_ hmn · simp only [Ioc_self, Ico_self, biUnion_empty] · intro k hmk ihk rw [← Ioc_union_Ioc_eq_Ioc (hf hmk) (hf <| le_succ _), union_comm, ← ihk] by_cases hk : Is...
997
import Mathlib.Order.SuccPred.Basic import Mathlib.Topology.Order.Basic import Mathlib.Topology.Metrizable.Uniformity #align_import topology.instances.discrete from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4" open Order Set TopologicalSpace Filter variable {α : Type*} [TopologicalSp...
Mathlib/Topology/Instances/Discrete.lean
51
63
theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder [PartialOrder α] [PredOrder α] [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] : (⊥ : TopologicalSpace α) = generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a } := by
refine (eq_bot_of_singletons_open fun a => ?_).symm have h_singleton_eq_inter : {a} = Iio (succ a) ∩ Ioi (pred a) := by suffices h_singleton_eq_inter' : {a} = Iic a ∩ Ici a by rw [h_singleton_eq_inter', ← Ioi_pred, ← Iio_succ] rw [inter_comm, Ici_inter_Iic, Icc_self a] rw [h_singleton_eq_inter] l...
998
import Mathlib.Order.SuccPred.Basic import Mathlib.Topology.Order.Basic import Mathlib.Topology.Metrizable.Uniformity #align_import topology.instances.discrete from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4" open Order Set TopologicalSpace Filter variable {α : Type*} [TopologicalSp...
Mathlib/Topology/Instances/Discrete.lean
66
72
theorem discreteTopology_iff_orderTopology_of_pred_succ' [PartialOrder α] [PredOrder α] [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] : DiscreteTopology α ↔ OrderTopology α := by
refine ⟨fun h => ⟨?_⟩, fun h => ⟨?_⟩⟩ · rw [h.eq_bot] exact bot_topologicalSpace_eq_generateFrom_of_pred_succOrder · rw [h.topology_eq_generate_intervals] exact bot_topologicalSpace_eq_generateFrom_of_pred_succOrder.symm
998
import Mathlib.Order.SuccPred.Basic import Mathlib.Topology.Order.Basic import Mathlib.Topology.Metrizable.Uniformity #align_import topology.instances.discrete from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4" open Order Set TopologicalSpace Filter variable {α : Type*} [TopologicalSp...
Mathlib/Topology/Instances/Discrete.lean
80
108
theorem LinearOrder.bot_topologicalSpace_eq_generateFrom [LinearOrder α] [PredOrder α] [SuccOrder α] : (⊥ : TopologicalSpace α) = generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a } := by
refine (eq_bot_of_singletons_open fun a => ?_).symm have h_singleton_eq_inter : {a} = Iic a ∩ Ici a := by rw [inter_comm, Ici_inter_Iic, Icc_self a] by_cases ha_top : IsTop a · rw [ha_top.Iic_eq, inter_comm, inter_univ] at h_singleton_eq_inter by_cases ha_bot : IsBot a · rw [ha_bot.Ici_eq] at h_singlet...
998
import Mathlib.Order.SuccPred.Basic import Mathlib.Topology.Order.Basic import Mathlib.Topology.Metrizable.Uniformity #align_import topology.instances.discrete from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4" open Order Set TopologicalSpace Filter variable {α : Type*} [TopologicalSp...
Mathlib/Topology/Instances/Discrete.lean
111
117
theorem discreteTopology_iff_orderTopology_of_pred_succ [LinearOrder α] [PredOrder α] [SuccOrder α] : DiscreteTopology α ↔ OrderTopology α := by
refine ⟨fun h => ⟨?_⟩, fun h => ⟨?_⟩⟩ · rw [h.eq_bot] exact LinearOrder.bot_topologicalSpace_eq_generateFrom · rw [h.topology_eq_generate_intervals] exact LinearOrder.bot_topologicalSpace_eq_generateFrom.symm
998
import Mathlib.Probability.Process.Filtration import Mathlib.Topology.Instances.Discrete #align_import probability.process.adapted from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982" open Filter Order TopologicalSpace open scoped Classical MeasureTheory NNReal ENNReal Topology namespa...
Mathlib/Probability/Process/Adapted.lean
99
105
theorem Filtration.adapted_natural [MetrizableSpace β] [mβ : MeasurableSpace β] [BorelSpace β] {u : ι → Ω → β} (hum : ∀ i, StronglyMeasurable[m] (u i)) : Adapted (Filtration.natural u hum) u := by
intro i refine StronglyMeasurable.mono ?_ (le_iSup₂_of_le i (le_refl i) le_rfl) rw [stronglyMeasurable_iff_measurable_separable] exact ⟨measurable_iff_comap_le.2 le_rfl, (hum i).isSeparable_range⟩
999
import Mathlib.Probability.Process.Filtration import Mathlib.Topology.Instances.Discrete #align_import probability.process.adapted from "leanprover-community/mathlib"@"f2ce6086713c78a7f880485f7917ea547a215982" open Filter Order TopologicalSpace open scoped Classical MeasureTheory NNReal ENNReal Topology namespa...
Mathlib/Probability/Process/Adapted.lean
188
198
theorem progMeasurable_of_tendsto' {γ} [MeasurableSpace ι] [PseudoMetrizableSpace β] (fltr : Filter γ) [fltr.NeBot] [fltr.IsCountablyGenerated] {U : γ → ι → Ω → β} (h : ∀ l, ProgMeasurable f (U l)) (h_tendsto : Tendsto U fltr (𝓝 u)) : ProgMeasurable f u := by
intro i apply @stronglyMeasurable_of_tendsto (Set.Iic i × Ω) β γ (MeasurableSpace.prod _ (f i)) _ _ fltr _ _ _ _ fun l => h l i rw [tendsto_pi_nhds] at h_tendsto ⊢ intro x specialize h_tendsto x.fst rw [tendsto_nhds] at h_tendsto ⊢ exact fun s hs h_mem => h_tendsto {g | g x.snd ∈ s} (hs.preimage (con...
999
import Mathlib.Order.SuccPred.Basic #align_import order.succ_pred.relation from "leanprover-community/mathlib"@"9aba7801eeecebb61f58a5763c2b6dd1b47dc6ef" open Function Order Relation Set section PartialSucc variable {α : Type*} [PartialOrder α] [SuccOrder α] [IsSuccArchimedean α]
Mathlib/Order/SuccPred/Relation.lean
26
35
theorem reflTransGen_of_succ_of_le (r : α → α → Prop) {n m : α} (h : ∀ i ∈ Ico n m, r i (succ i)) (hnm : n ≤ m) : ReflTransGen r n m := by
revert h; refine Succ.rec ?_ ?_ hnm · intro _ exact ReflTransGen.refl · intro m hnm ih h have : ReflTransGen r n m := ih fun i hi => h i ⟨hi.1, hi.2.trans_le <| le_succ m⟩ rcases (le_succ m).eq_or_lt with hm | hm · rwa [← hm] exact this.tail (h m ⟨hnm, hm⟩)
1,000
import Mathlib.Order.SuccPred.Basic #align_import order.succ_pred.relation from "leanprover-community/mathlib"@"9aba7801eeecebb61f58a5763c2b6dd1b47dc6ef" open Function Order Relation Set section PartialSucc variable {α : Type*} [PartialOrder α] [SuccOrder α] [IsSuccArchimedean α] theorem reflTransGen_of_succ_...
Mathlib/Order/SuccPred/Relation.lean
40
43
theorem reflTransGen_of_succ_of_ge (r : α → α → Prop) {n m : α} (h : ∀ i ∈ Ico m n, r (succ i) i) (hmn : m ≤ n) : ReflTransGen r n m := by
rw [← reflTransGen_swap] exact reflTransGen_of_succ_of_le (swap r) h hmn
1,000
import Mathlib.Data.Set.Image import Mathlib.Order.SuccPred.Relation import Mathlib.Topology.Clopen import Mathlib.Topology.Irreducible #align_import topology.connected from "leanprover-community/mathlib"@"d101e93197bb5f6ea89bd7ba386b7f7dff1f3903" open Set Function Topology TopologicalSpace Relation open scoped C...
Mathlib/Topology/Connected/Basic.lean
96
111
theorem isPreconnected_of_forall {s : Set α} (x : α) (H : ∀ y ∈ s, ∃ t, t ⊆ s ∧ x ∈ t ∧ y ∈ t ∧ IsPreconnected t) : IsPreconnected s := by
rintro u v hu hv hs ⟨z, zs, zu⟩ ⟨y, ys, yv⟩ have xs : x ∈ s := by rcases H y ys with ⟨t, ts, xt, -, -⟩ exact ts xt -- Porting note (#11215): TODO: use `wlog xu : x ∈ u := hs xs using u v y z, v u z y` cases hs xs with | inl xu => rcases H y ys with ⟨t, ts, xt, yt, ht⟩ have := ht u v hu hv (ts...
1,001
import Mathlib.Data.Set.Image import Mathlib.Order.SuccPred.Relation import Mathlib.Topology.Clopen import Mathlib.Topology.Irreducible #align_import topology.connected from "leanprover-community/mathlib"@"d101e93197bb5f6ea89bd7ba386b7f7dff1f3903" open Set Function Topology TopologicalSpace Relation open scoped C...
Mathlib/Topology/Connected/Basic.lean
116
120
theorem isPreconnected_of_forall_pair {s : Set α} (H : ∀ x ∈ s, ∀ y ∈ s, ∃ t, t ⊆ s ∧ x ∈ t ∧ y ∈ t ∧ IsPreconnected t) : IsPreconnected s := by
rcases eq_empty_or_nonempty s with (rfl | ⟨x, hx⟩) exacts [isPreconnected_empty, isPreconnected_of_forall x fun y => H x hx y]
1,001
import Mathlib.Data.Set.Image import Mathlib.Order.SuccPred.Relation import Mathlib.Topology.Clopen import Mathlib.Topology.Irreducible #align_import topology.connected from "leanprover-community/mathlib"@"d101e93197bb5f6ea89bd7ba386b7f7dff1f3903" open Set Function Topology TopologicalSpace Relation open scoped C...
Mathlib/Topology/Connected/Basic.lean
124
128
theorem isPreconnected_sUnion (x : α) (c : Set (Set α)) (H1 : ∀ s ∈ c, x ∈ s) (H2 : ∀ s ∈ c, IsPreconnected s) : IsPreconnected (⋃₀ c) := by
apply isPreconnected_of_forall x rintro y ⟨s, sc, ys⟩ exact ⟨s, subset_sUnion_of_mem sc, H1 s sc, ys, H2 s sc⟩
1,001
import Mathlib.Data.Set.Image import Mathlib.Order.SuccPred.Relation import Mathlib.Topology.Clopen import Mathlib.Topology.Irreducible #align_import topology.connected from "leanprover-community/mathlib"@"d101e93197bb5f6ea89bd7ba386b7f7dff1f3903" open Set Function Topology TopologicalSpace Relation open scoped C...
Mathlib/Topology/Connected/Basic.lean
142
145
theorem IsPreconnected.union' {s t : Set α} (H : (s ∩ t).Nonempty) (hs : IsPreconnected s) (ht : IsPreconnected t) : IsPreconnected (s ∪ t) := by
rcases H with ⟨x, hxs, hxt⟩ exact hs.union x hxs hxt ht
1,001
import Mathlib.Data.Set.Image import Mathlib.Order.SuccPred.Relation import Mathlib.Topology.Clopen import Mathlib.Topology.Irreducible #align_import topology.connected from "leanprover-community/mathlib"@"d101e93197bb5f6ea89bd7ba386b7f7dff1f3903" open Set Function Topology TopologicalSpace Relation open scoped C...
Mathlib/Topology/Connected/Basic.lean
148
153
theorem IsConnected.union {s t : Set α} (H : (s ∩ t).Nonempty) (Hs : IsConnected s) (Ht : IsConnected t) : IsConnected (s ∪ t) := by
rcases H with ⟨x, hx⟩ refine ⟨⟨x, mem_union_left t (mem_of_mem_inter_left hx)⟩, ?_⟩ exact Hs.isPreconnected.union x (mem_of_mem_inter_left hx) (mem_of_mem_inter_right hx) Ht.isPreconnected
1,001
import Mathlib.Topology.Connected.Basic open Set Function universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section TotallyDisconnected def IsTotallyDisconnected (s : Set α) : Prop := ∀ t, t ⊆ s → IsPreconnected t → t.Subsingleton #align is_t...
Mathlib/Topology/Connected/TotallyDisconnected.lean
93
104
theorem isTotallyDisconnected_of_isClopen_set {X : Type*} [TopologicalSpace X] (hX : Pairwise fun x y => ∃ (U : Set X), IsClopen U ∧ x ∈ U ∧ y ∉ U) : IsTotallyDisconnected (Set.univ : Set X) := by
rintro S - hS unfold Set.Subsingleton by_contra! h_contra rcases h_contra with ⟨x, hx, y, hy, hxy⟩ obtain ⟨U, hU, hxU, hyU⟩ := hX hxy specialize hS U Uᶜ hU.2 hU.compl.2 (fun a _ => em (a ∈ U)) ⟨x, hx, hxU⟩ ⟨y, hy, hyU⟩ rw [inter_compl_self, Set.inter_empty] at hS exact Set.not_nonempty_empty hS
1,002
import Mathlib.Topology.Connected.Basic open Set Function universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section TotallyDisconnected def IsTotallyDisconnected (s : Set α) : Prop := ∀ t, t ⊆ s → IsPreconnected t → t.Subsingleton #align is_t...
Mathlib/Topology/Connected/TotallyDisconnected.lean
108
119
theorem totallyDisconnectedSpace_iff_connectedComponent_subsingleton : TotallyDisconnectedSpace α ↔ ∀ x : α, (connectedComponent x).Subsingleton := by
constructor · intro h x apply h.1 · exact subset_univ _ exact isPreconnected_connectedComponent intro h; constructor intro s s_sub hs rcases eq_empty_or_nonempty s with (rfl | ⟨x, x_in⟩) · exact subsingleton_empty · exact (h x).anti (hs.subset_connectedComponent x_in)
1,002
import Mathlib.Topology.Connected.Basic open Set Function universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section TotallyDisconnected def IsTotallyDisconnected (s : Set α) : Prop := ∀ t, t ⊆ s → IsPreconnected t → t.Subsingleton #align is_t...
Mathlib/Topology/Connected/TotallyDisconnected.lean
123
128
theorem totallyDisconnectedSpace_iff_connectedComponent_singleton : TotallyDisconnectedSpace α ↔ ∀ x : α, connectedComponent x = {x} := by
rw [totallyDisconnectedSpace_iff_connectedComponent_subsingleton] refine forall_congr' fun x => ?_ rw [subsingleton_iff_singleton] exact mem_connectedComponent
1,002
import Mathlib.Topology.Compactness.SigmaCompact import Mathlib.Topology.Connected.TotallyDisconnected import Mathlib.Topology.Inseparable #align_import topology.separation from "leanprover-community/mathlib"@"d91e7f7a7f1c7e9f0e18fdb6bde4f652004c735d" open Function Set Filter Topology TopologicalSpace open scoped...
Mathlib/Topology/Separation.lean
125
127
theorem separatedNhds_iff_disjoint {s t : Set X} : SeparatedNhds s t ↔ Disjoint (𝓝ˢ s) (𝓝ˢ t) := by
simp only [(hasBasis_nhdsSet s).disjoint_iff (hasBasis_nhdsSet t), SeparatedNhds, exists_prop, ← exists_and_left, and_assoc, and_comm, and_left_comm]
1,003
import Mathlib.Topology.Compactness.SigmaCompact import Mathlib.Topology.Connected.TotallyDisconnected import Mathlib.Topology.Inseparable #align_import topology.separation from "leanprover-community/mathlib"@"d91e7f7a7f1c7e9f0e18fdb6bde4f652004c735d" open Function Set Filter Topology TopologicalSpace open scoped...
Mathlib/Topology/Separation.lean
178
179
theorem union_left : SeparatedNhds s u → SeparatedNhds t u → SeparatedNhds (s ∪ t) u := by
simpa only [separatedNhds_iff_disjoint, nhdsSet_union, disjoint_sup_left] using And.intro
1,003
import Mathlib.Topology.Compactness.SigmaCompact import Mathlib.Topology.Connected.TotallyDisconnected import Mathlib.Topology.Inseparable #align_import topology.separation from "leanprover-community/mathlib"@"d91e7f7a7f1c7e9f0e18fdb6bde4f652004c735d" open Function Set Filter Topology TopologicalSpace open scoped...
Mathlib/Topology/Separation.lean
201
203
theorem t0Space_iff_not_inseparable (X : Type u) [TopologicalSpace X] : T0Space X ↔ Pairwise fun x y : X => ¬Inseparable x y := by
simp only [t0Space_iff_inseparable, Ne, not_imp_not, Pairwise]
1,003
import Mathlib.Topology.Compactness.SigmaCompact import Mathlib.Topology.Connected.TotallyDisconnected import Mathlib.Topology.Inseparable #align_import topology.separation from "leanprover-community/mathlib"@"d91e7f7a7f1c7e9f0e18fdb6bde4f652004c735d" open Function Set Filter Topology TopologicalSpace open scoped...
Mathlib/Topology/Separation.lean
261
264
theorem t0Space_iff_exists_isOpen_xor'_mem (X : Type u) [TopologicalSpace X] : T0Space X ↔ Pairwise fun x y => ∃ U : Set X, IsOpen U ∧ Xor' (x ∈ U) (y ∈ U) := by
simp only [t0Space_iff_not_inseparable, xor_iff_not_iff, not_forall, exists_prop, inseparable_iff_forall_open, Pairwise]
1,003
import Mathlib.Topology.Constructions import Mathlib.Topology.Separation open Set Filter Function Topology variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] {f : X → Y} section codiscrete_filter
Mathlib/Topology/DiscreteSubset.lean
83
92
theorem isClosed_and_discrete_iff {S : Set X} : IsClosed S ∧ DiscreteTopology S ↔ ∀ x, Disjoint (𝓝[≠] x) (𝓟 S) := by
rw [discreteTopology_subtype_iff, isClosed_iff_clusterPt, ← forall_and] congrm (∀ x, ?_) rw [← not_imp_not, clusterPt_iff_not_disjoint, not_not, ← disjoint_iff] constructor <;> intro H · by_cases hx : x ∈ S exacts [H.2 hx, (H.1 hx).mono_left nhdsWithin_le_nhds] · refine ⟨fun hx ↦ ?_, fun _ ↦ H⟩ sim...
1,004
import Mathlib.Topology.Connected.Basic import Mathlib.Topology.Separation open scoped Topology variable {X Y A} [TopologicalSpace X] [TopologicalSpace A] theorem embedding_toPullbackDiag (f : X → Y) : Embedding (toPullbackDiag f) := Embedding.mk' _ (injective_toPullbackDiag f) fun x ↦ by rw [toPullbackDiag,...
Mathlib/Topology/SeparatedMap.lean
79
87
theorem isSeparatedMap_iff_isClosed_diagonal {f : X → Y} : IsSeparatedMap f ↔ IsClosed f.pullbackDiagonal := by
simp_rw [isSeparatedMap_iff_nhds, ← isOpen_compl_iff, isOpen_iff_mem_nhds, Subtype.forall, Prod.forall, nhds_induced, nhds_prod_eq] refine forall₄_congr fun x₁ x₂ _ _ ↦ ⟨fun h ↦ ?_, fun ⟨t, ht, t_sub⟩ ↦ ?_⟩ · simp_rw [← Filter.disjoint_iff, ← compl_diagonal_mem_prod] at h exact ⟨_, h, subset_rfl⟩ · obt...
1,005
import Mathlib.Topology.Connected.Basic import Mathlib.Topology.Separation open scoped Topology variable {X Y A} [TopologicalSpace X] [TopologicalSpace A] theorem embedding_toPullbackDiag (f : X → Y) : Embedding (toPullbackDiag f) := Embedding.mk' _ (injective_toPullbackDiag f) fun x ↦ by rw [toPullbackDiag,...
Mathlib/Topology/SeparatedMap.lean
89
92
theorem isSeparatedMap_iff_closedEmbedding {f : X → Y} : IsSeparatedMap f ↔ ClosedEmbedding (toPullbackDiag f) := by
rw [isSeparatedMap_iff_isClosed_diagonal, ← range_toPullbackDiag] exact ⟨fun h ↦ ⟨embedding_toPullbackDiag f, h⟩, fun h ↦ h.isClosed_range⟩
1,005
import Mathlib.Topology.Connected.Basic import Mathlib.Topology.Separation open scoped Topology variable {X Y A} [TopologicalSpace X] [TopologicalSpace A] theorem embedding_toPullbackDiag (f : X → Y) : Embedding (toPullbackDiag f) := Embedding.mk' _ (injective_toPullbackDiag f) fun x ↦ by rw [toPullbackDiag,...
Mathlib/Topology/SeparatedMap.lean
101
106
theorem IsSeparatedMap.pullback {f : X → Y} (sep : IsSeparatedMap f) (g : A → Y) : IsSeparatedMap (@snd X Y A f g) := by
rw [isSeparatedMap_iff_isClosed_diagonal] at sep ⊢ rw [← preimage_map_fst_pullbackDiagonal] refine sep.preimage (Continuous.mapPullback ?_ ?_) <;> apply_rules [continuous_fst, continuous_subtype_val, Continuous.comp]
1,005
import Mathlib.Topology.Connected.Basic import Mathlib.Topology.Separation open scoped Topology variable {X Y A} [TopologicalSpace X] [TopologicalSpace A] theorem embedding_toPullbackDiag (f : X → Y) : Embedding (toPullbackDiag f) := Embedding.mk' _ (injective_toPullbackDiag f) fun x ↦ by rw [toPullbackDiag,...
Mathlib/Topology/SeparatedMap.lean
111
115
theorem IsSeparatedMap.comp_right {f : X → Y} (sep : IsSeparatedMap f) {g : A → X} (cont : Continuous g) (inj : g.Injective) : IsSeparatedMap (f ∘ g) := by
rw [isSeparatedMap_iff_isClosed_diagonal] at sep ⊢ rw [← inj.preimage_pullbackDiagonal] exact sep.preimage (cont.mapPullback cont)
1,005
import Mathlib.Topology.PartialHomeomorph import Mathlib.Topology.SeparatedMap #align_import topology.is_locally_homeomorph from "leanprover-community/mathlib"@"e97cf15cd1aec9bd5c193b2ffac5a6dc9118912b" open Topology variable {X Y Z : Type*} [TopologicalSpace X] [TopologicalSpace Y] [TopologicalSpace Z] (g : Y →...
Mathlib/Topology/IsLocalHomeomorph.lean
45
59
theorem isLocalHomeomorphOn_iff_openEmbedding_restrict {f : X → Y} : IsLocalHomeomorphOn f s ↔ ∀ x ∈ s, ∃ U ∈ 𝓝 x, OpenEmbedding (U.restrict f) := by
refine ⟨fun h x hx ↦ ?_, fun h x hx ↦ ?_⟩ · obtain ⟨e, hxe, rfl⟩ := h x hx exact ⟨e.source, e.open_source.mem_nhds hxe, e.openEmbedding_restrict⟩ · obtain ⟨U, hU, emb⟩ := h x hx have : OpenEmbedding ((interior U).restrict f) := by refine emb.comp ⟨embedding_inclusion interior_subset, ?_⟩ rw [...
1,006
import Mathlib.Topology.PartialHomeomorph import Mathlib.Topology.SeparatedMap #align_import topology.is_locally_homeomorph from "leanprover-community/mathlib"@"e97cf15cd1aec9bd5c193b2ffac5a6dc9118912b" open Topology variable {X Y Z : Type*} [TopologicalSpace X] [TopologicalSpace Y] [TopologicalSpace Z] (g : Y →...
Mathlib/Topology/IsLocalHomeomorph.lean
66
77
theorem mk (h : ∀ x ∈ s, ∃ e : PartialHomeomorph X Y, x ∈ e.source ∧ Set.EqOn f e e.source) : IsLocalHomeomorphOn f s := by
intro x hx obtain ⟨e, hx, he⟩ := h x hx exact ⟨{ e with toFun := f map_source' := fun _x hx ↦ by rw [he hx]; exact e.map_source' hx left_inv' := fun _x hx ↦ by rw [he hx]; exact e.left_inv' hx right_inv' := fun _y hy ↦ by rw [he (e.map_target' hy)]; exact e.right_inv' hy ...
1,006
import Mathlib.Topology.PartialHomeomorph import Mathlib.Topology.SeparatedMap #align_import topology.is_locally_homeomorph from "leanprover-community/mathlib"@"e97cf15cd1aec9bd5c193b2ffac5a6dc9118912b" open Topology variable {X Y Z : Type*} [TopologicalSpace X] [TopologicalSpace Y] [TopologicalSpace Z] (g : Y →...
Mathlib/Topology/IsLocalHomeomorph.lean
90
99
theorem of_comp_left (hgf : IsLocalHomeomorphOn (g ∘ f) s) (hg : IsLocalHomeomorphOn g (f '' s)) (cont : ∀ x ∈ s, ContinuousAt f x) : IsLocalHomeomorphOn f s := mk f s fun x hx ↦ by obtain ⟨g, hxg, rfl⟩ := hg (f x) ⟨x, hx, rfl⟩ obtain ⟨gf, hgf, he⟩ := hgf x hx refine ⟨(gf.restr <| f ⁻¹' g.source).trans g.symm...
apply interior_subset hy.1.2 rw [← he, g.eq_symm_apply this (by apply g.map_source this), Function.comp_apply]
1,006
import Mathlib.Topology.PartialHomeomorph import Mathlib.Topology.SeparatedMap #align_import topology.is_locally_homeomorph from "leanprover-community/mathlib"@"e97cf15cd1aec9bd5c193b2ffac5a6dc9118912b" open Topology variable {X Y Z : Type*} [TopologicalSpace X] [TopologicalSpace Y] [TopologicalSpace Z] (g : Y →...
Mathlib/Topology/IsLocalHomeomorph.lean
155
158
theorem isLocalHomeomorph_iff_openEmbedding_restrict {f : X → Y} : IsLocalHomeomorph f ↔ ∀ x : X, ∃ U ∈ 𝓝 x, OpenEmbedding (U.restrict f) := by
simp_rw [isLocalHomeomorph_iff_isLocalHomeomorphOn_univ, isLocalHomeomorphOn_iff_openEmbedding_restrict, imp_iff_right (Set.mem_univ _)]
1,006
import Mathlib.Topology.IsLocalHomeomorph import Mathlib.Topology.FiberBundle.Basic #align_import topology.covering from "leanprover-community/mathlib"@"e473c3198bb41f68560cab68a0529c854b618833" open Bundle variable {E X : Type*} [TopologicalSpace E] [TopologicalSpace X] (f : E → X) (s : Set X) def IsEvenlyCov...
Mathlib/Topology/Covering.lean
140
141
theorem isCoveringMap_iff_isCoveringMapOn_univ : IsCoveringMap f ↔ IsCoveringMapOn f Set.univ := by
simp only [IsCoveringMap, IsCoveringMapOn, Set.mem_univ, forall_true_left]
1,007
import Mathlib.Dynamics.FixedPoints.Basic import Mathlib.Topology.Separation #align_import dynamics.fixed_points.topology from "leanprover-community/mathlib"@"d90e4e186f1d18e375dcd4e5b5f6364b01cb3e46" variable {α : Type*} [TopologicalSpace α] [T2Space α] {f : α → α} open Function Filter open Topology
Mathlib/Dynamics/FixedPoints/Topology.lean
33
37
theorem isFixedPt_of_tendsto_iterate {x y : α} (hy : Tendsto (fun n => f^[n] x) atTop (𝓝 y)) (hf : ContinuousAt f y) : IsFixedPt f y := by
refine tendsto_nhds_unique ((tendsto_add_atTop_iff_nat 1).1 ?_) hy simp only [iterate_succ' f] exact hf.tendsto.comp hy
1,008
import Mathlib.Topology.Separation #align_import topology.shrinking_lemma from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514" open Set Function open scoped Classical noncomputable section variable {ι X : Type*} [TopologicalSpace X] [NormalSpace X] namespace ShrinkingLemma -- the tr...
Mathlib/Topology/ShrinkingLemma.lean
118
121
theorem find_mem {c : Set (PartialRefinement u s)} (i : ι) (ne : c.Nonempty) : find c ne i ∈ c := by
rw [find] split_ifs with h exacts [h.choose_spec.1, ne.some_mem]
1,009
import Mathlib.Topology.Separation #align_import topology.shrinking_lemma from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514" open Set Function open scoped Classical noncomputable section variable {ι X : Type*} [TopologicalSpace X] [NormalSpace X] namespace ShrinkingLemma -- the tr...
Mathlib/Topology/ShrinkingLemma.lean
124
132
theorem mem_find_carrier_iff {c : Set (PartialRefinement u s)} {i : ι} (ne : c.Nonempty) : i ∈ (find c ne i).carrier ↔ i ∈ chainSupCarrier c := by
rw [find] split_ifs with h · have := h.choose_spec exact iff_of_true this.2 (mem_iUnion₂.2 ⟨_, this.1, this.2⟩) · push_neg at h refine iff_of_false (h _ ne.some_mem) ?_ simpa only [chainSupCarrier, mem_iUnion₂, not_exists]
1,009
import Mathlib.Topology.Separation #align_import topology.extend_from from "leanprover-community/mathlib"@"b363547b3113d350d053abdf2884e9850a56b205" noncomputable section open Topology open Filter Set variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] def extendFrom (A : Set X) (f : X → Y) : X ...
Mathlib/Topology/ExtendFrom.lean
63
81
theorem continuousOn_extendFrom [RegularSpace Y] {f : X → Y} {A B : Set X} (hB : B ⊆ closure A) (hf : ∀ x ∈ B, ∃ y, Tendsto f (𝓝[A] x) (𝓝 y)) : ContinuousOn (extendFrom A f) B := by
set φ := extendFrom A f intro x x_in suffices ∀ V' ∈ 𝓝 (φ x), IsClosed V' → φ ⁻¹' V' ∈ 𝓝[B] x by simpa [ContinuousWithinAt, (closed_nhds_basis (φ x)).tendsto_right_iff] intro V' V'_in V'_closed obtain ⟨V, V_in, V_op, hV⟩ : ∃ V ∈ 𝓝 x, IsOpen V ∧ V ∩ A ⊆ f ⁻¹' V' := by have := tendsto_extendFrom (hf...
1,010
import Mathlib.Topology.Separation #align_import topology.extend_from from "leanprover-community/mathlib"@"b363547b3113d350d053abdf2884e9850a56b205" noncomputable section open Topology open Filter Set variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y] def extendFrom (A : Set X) (f : X → Y) : X ...
Mathlib/Topology/ExtendFrom.lean
86
89
theorem continuous_extendFrom [RegularSpace Y] {f : X → Y} {A : Set X} (hA : Dense A) (hf : ∀ x, ∃ y, Tendsto f (𝓝[A] x) (𝓝 y)) : Continuous (extendFrom A f) := by
rw [continuous_iff_continuousOn_univ] exact continuousOn_extendFrom (fun x _ ↦ hA x) (by simpa using hf)
1,010
import Mathlib.Topology.ExtendFrom import Mathlib.Topology.Order.DenselyOrdered #align_import topology.algebra.order.extend_from from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" set_option autoImplicit true open Filter Set TopologicalSpace open scoped Classical open Topology
Mathlib/Topology/Order/ExtendFrom.lean
23
33
theorem continuousOn_Icc_extendFrom_Ioo [TopologicalSpace α] [LinearOrder α] [DenselyOrdered α] [OrderTopology α] [TopologicalSpace β] [RegularSpace β] {f : α → β} {a b : α} {la lb : β} (hab : a ≠ b) (hf : ContinuousOn f (Ioo a b)) (ha : Tendsto f (𝓝[>] a) (𝓝 la)) (hb : Tendsto f (𝓝[<] b) (𝓝 lb)) : Cont...
apply continuousOn_extendFrom · rw [closure_Ioo hab] · intro x x_in rcases eq_endpoints_or_mem_Ioo_of_mem_Icc x_in with (rfl | rfl | h) · exact ⟨la, ha.mono_left <| nhdsWithin_mono _ Ioo_subset_Ioi_self⟩ · exact ⟨lb, hb.mono_left <| nhdsWithin_mono _ Ioo_subset_Iio_self⟩ · exact ⟨f x, hf x h⟩
1,011
import Mathlib.Topology.ExtendFrom import Mathlib.Topology.Order.DenselyOrdered #align_import topology.algebra.order.extend_from from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" set_option autoImplicit true open Filter Set TopologicalSpace open scoped Classical open Topology theor...
Mathlib/Topology/Order/ExtendFrom.lean
36
42
theorem eq_lim_at_left_extendFrom_Ioo [TopologicalSpace α] [LinearOrder α] [DenselyOrdered α] [OrderTopology α] [TopologicalSpace β] [T2Space β] {f : α → β} {a b : α} {la : β} (hab : a < b) (ha : Tendsto f (𝓝[>] a) (𝓝 la)) : extendFrom (Ioo a b) f a = la := by
apply extendFrom_eq · rw [closure_Ioo hab.ne] simp only [le_of_lt hab, left_mem_Icc, right_mem_Icc] · simpa [hab]
1,011
import Mathlib.Topology.ExtendFrom import Mathlib.Topology.Order.DenselyOrdered #align_import topology.algebra.order.extend_from from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" set_option autoImplicit true open Filter Set TopologicalSpace open scoped Classical open Topology theor...
Mathlib/Topology/Order/ExtendFrom.lean
45
51
theorem eq_lim_at_right_extendFrom_Ioo [TopologicalSpace α] [LinearOrder α] [DenselyOrdered α] [OrderTopology α] [TopologicalSpace β] [T2Space β] {f : α → β} {a b : α} {lb : β} (hab : a < b) (hb : Tendsto f (𝓝[<] b) (𝓝 lb)) : extendFrom (Ioo a b) f b = lb := by
apply extendFrom_eq · rw [closure_Ioo hab.ne] simp only [le_of_lt hab, left_mem_Icc, right_mem_Icc] · simpa [hab]
1,011
import Mathlib.Topology.ExtendFrom import Mathlib.Topology.Order.DenselyOrdered #align_import topology.algebra.order.extend_from from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" set_option autoImplicit true open Filter Set TopologicalSpace open scoped Classical open Topology theor...
Mathlib/Topology/Order/ExtendFrom.lean
54
65
theorem continuousOn_Ico_extendFrom_Ioo [TopologicalSpace α] [LinearOrder α] [DenselyOrdered α] [OrderTopology α] [TopologicalSpace β] [RegularSpace β] {f : α → β} {a b : α} {la : β} (hab : a < b) (hf : ContinuousOn f (Ioo a b)) (ha : Tendsto f (𝓝[>] a) (𝓝 la)) : ContinuousOn (extendFrom (Ioo a b) f) (Ico...
apply continuousOn_extendFrom · rw [closure_Ioo hab.ne] exact Ico_subset_Icc_self · intro x x_in rcases eq_left_or_mem_Ioo_of_mem_Ico x_in with (rfl | h) · use la simpa [hab] · exact ⟨f x, hf x h⟩
1,011
import Mathlib.Topology.ExtendFrom import Mathlib.Topology.Order.DenselyOrdered #align_import topology.algebra.order.extend_from from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" set_option autoImplicit true open Filter Set TopologicalSpace open scoped Classical open Topology theor...
Mathlib/Topology/Order/ExtendFrom.lean
68
74
theorem continuousOn_Ioc_extendFrom_Ioo [TopologicalSpace α] [LinearOrder α] [DenselyOrdered α] [OrderTopology α] [TopologicalSpace β] [RegularSpace β] {f : α → β} {a b : α} {lb : β} (hab : a < b) (hf : ContinuousOn f (Ioo a b)) (hb : Tendsto f (𝓝[<] b) (𝓝 lb)) : ContinuousOn (extendFrom (Ioo a b) f) (Ioc...
have := @continuousOn_Ico_extendFrom_Ioo αᵒᵈ _ _ _ _ _ _ _ f _ _ lb hab erw [dual_Ico, dual_Ioi, dual_Ioo] at this exact this hf hb
1,011
import Mathlib.Topology.Order.ExtendFrom import Mathlib.Topology.Algebra.Order.Compact import Mathlib.Topology.Order.LocalExtr import Mathlib.Topology.Order.T5 #align_import analysis.calculus.local_extr from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe" open Filter Set Topology variabl...
Mathlib/Topology/Algebra/Order/Rolle.lean
37
55
theorem exists_Ioo_extr_on_Icc (hab : a < b) (hfc : ContinuousOn f (Icc a b)) (hfI : f a = f b) : ∃ c ∈ Ioo a b, IsExtrOn f (Icc a b) c := by
have ne : (Icc a b).Nonempty := nonempty_Icc.2 (le_of_lt hab) -- Consider absolute min and max points obtain ⟨c, cmem, cle⟩ : ∃ c ∈ Icc a b, ∀ x ∈ Icc a b, f c ≤ f x := isCompact_Icc.exists_isMinOn ne hfc obtain ⟨C, Cmem, Cge⟩ : ∃ C ∈ Icc a b, ∀ x ∈ Icc a b, f x ≤ f C := isCompact_Icc.exists_isMaxOn ne...
1,012
import Mathlib.Analysis.Calculus.LocalExtr.Basic import Mathlib.Topology.Algebra.Order.Rolle #align_import analysis.calculus.local_extr from "leanprover-community/mathlib"@"3bce8d800a6f2b8f63fe1e588fd76a9ff4adcebe" open Set Filter Topology variable {f f' : ℝ → ℝ} {a b l : ℝ} theorem exists_hasDerivAt_eq_zero (h...
Mathlib/Analysis/Calculus/LocalExtr/Rolle.lean
78
84
theorem exists_deriv_eq_zero' (hab : a < b) (hfa : Tendsto f (𝓝[>] a) (𝓝 l)) (hfb : Tendsto f (𝓝[<] b) (𝓝 l)) : ∃ c ∈ Ioo a b, deriv f c = 0 := by
by_cases h : ∀ x ∈ Ioo a b, DifferentiableAt ℝ f x · exact exists_hasDerivAt_eq_zero' hab hfa hfb fun x hx => (h x hx).hasDerivAt · obtain ⟨c, hc, hcdiff⟩ : ∃ x ∈ Ioo a b, ¬DifferentiableAt ℝ f x := by push_neg at h; exact h exact ⟨c, hc, deriv_zero_of_not_differentiableAt hcdiff⟩
1,013
import Mathlib.Data.Fintype.Option import Mathlib.Topology.Separation import Mathlib.Topology.Sets.Opens #align_import topology.alexandroff from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988" open Set Filter Topology variable {X : Type*} def OnePoint (X : Type*) := Option X #ali...
Mathlib/Topology/Compactification/OnePoint.lean
140
141
theorem compl_image_coe (s : Set X) : ((↑) '' s : Set (OnePoint X))ᶜ = (↑) '' sᶜ ∪ {∞} := by
rw [coe_injective.compl_image_eq, compl_range_coe]
1,014
import Mathlib.Data.Fintype.Option import Mathlib.Topology.Separation import Mathlib.Topology.Sets.Opens #align_import topology.alexandroff from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988" open Set Filter Topology variable {X : Type*} def OnePoint (X : Type*) := Option X #ali...
Mathlib/Topology/Compactification/OnePoint.lean
144
145
theorem ne_infty_iff_exists {x : OnePoint X} : x ≠ ∞ ↔ ∃ y : X, (y : OnePoint X) = x := by
induction x using OnePoint.rec <;> simp
1,014
import Mathlib.Data.Fintype.Option import Mathlib.Topology.Separation import Mathlib.Topology.Sets.Opens #align_import topology.alexandroff from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988" open Set Filter Topology variable {X : Type*} def OnePoint (X : Type*) := Option X #ali...
Mathlib/Topology/Compactification/OnePoint.lean
152
153
theorem not_mem_range_coe_iff {x : OnePoint X} : x ∉ range some ↔ x = ∞ := by
rw [← mem_compl_iff, compl_range_coe, mem_singleton_iff]
1,014
import Mathlib.Data.Fintype.Option import Mathlib.Topology.Separation import Mathlib.Topology.Sets.Opens #align_import topology.alexandroff from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988" open Set Filter Topology variable {X : Type*} def OnePoint (X : Type*) := Option X #ali...
Mathlib/Topology/Compactification/OnePoint.lean
165
167
theorem coe_preimage_infty : ((↑) : X → OnePoint X) ⁻¹' {∞} = ∅ := by
ext simp
1,014
import Mathlib.Topology.Separation import Mathlib.Topology.Bases #align_import topology.dense_embedding from "leanprover-community/mathlib"@"148aefbd371a25f1cff33c85f20c661ce3155def" noncomputable section open Set Filter open scoped Topology variable {α : Type*} {β : Type*} {γ : Type*} {δ : Type*} structure D...
Mathlib/Topology/DenseEmbedding.lean
65
72
theorem closure_image_mem_nhds {s : Set α} {a : α} (di : DenseInducing i) (hs : s ∈ 𝓝 a) : closure (i '' s) ∈ 𝓝 (i a) := by
rw [di.nhds_eq_comap a, ((nhds_basis_opens _).comap _).mem_iff] at hs rcases hs with ⟨U, ⟨haU, hUo⟩, sub : i ⁻¹' U ⊆ s⟩ refine mem_of_superset (hUo.mem_nhds haU) ?_ calc U ⊆ closure (i '' (i ⁻¹' U)) := di.dense.subset_closure_image_preimage_of_isOpen hUo _ ⊆ closure (i '' s) := closure_mono (image_subs...
1,015
import Mathlib.Topology.Separation import Mathlib.Topology.Bases #align_import topology.dense_embedding from "leanprover-community/mathlib"@"148aefbd371a25f1cff33c85f20c661ce3155def" noncomputable section open Set Filter open scoped Topology variable {α : Type*} {β : Type*} {γ : Type*} {δ : Type*} structure D...
Mathlib/Topology/DenseEmbedding.lean
75
78
theorem dense_image (di : DenseInducing i) {s : Set α} : Dense (i '' s) ↔ Dense s := by
refine ⟨fun H x => ?_, di.dense.dense_image di.continuous⟩ rw [di.toInducing.closure_eq_preimage_closure_image, H.closure_eq, preimage_univ] trivial
1,015
import Mathlib.Topology.Separation import Mathlib.Topology.Bases #align_import topology.dense_embedding from "leanprover-community/mathlib"@"148aefbd371a25f1cff33c85f20c661ce3155def" noncomputable section open Set Filter open scoped Topology variable {α : Type*} {β : Type*} {γ : Type*} {δ : Type*} structure D...
Mathlib/Topology/DenseEmbedding.lean
83
90
theorem interior_compact_eq_empty [T2Space β] (di : DenseInducing i) (hd : Dense (range i)ᶜ) {s : Set α} (hs : IsCompact s) : interior s = ∅ := by
refine eq_empty_iff_forall_not_mem.2 fun x hx => ?_ rw [mem_interior_iff_mem_nhds] at hx have := di.closure_image_mem_nhds hx rw [(hs.image di.continuous).isClosed.closure_eq] at this rcases hd.inter_nhds_nonempty this with ⟨y, hyi, hys⟩ exact hyi (image_subset_range _ _ hys)
1,015
import Mathlib.Topology.Separation import Mathlib.Topology.Bases #align_import topology.dense_embedding from "leanprover-community/mathlib"@"148aefbd371a25f1cff33c85f20c661ce3155def" noncomputable section open Set Filter open scoped Topology variable {α : Type*} {β : Type*} {γ : Type*} {δ : Type*} structure D...
Mathlib/Topology/DenseEmbedding.lean
117
124
theorem tendsto_comap_nhds_nhds {d : δ} {a : α} (di : DenseInducing i) (H : Tendsto h (𝓝 d) (𝓝 (i a))) (comm : h ∘ g = i ∘ f) : Tendsto f (comap g (𝓝 d)) (𝓝 a) := by
have lim1 : map g (comap g (𝓝 d)) ≤ 𝓝 d := map_comap_le replace lim1 : map h (map g (comap g (𝓝 d))) ≤ map h (𝓝 d) := map_mono lim1 rw [Filter.map_map, comm, ← Filter.map_map, map_le_iff_le_comap] at lim1 have lim2 : comap i (map h (𝓝 d)) ≤ comap i (𝓝 (i a)) := comap_mono H rw [← di.nhds_eq_comap] at l...
1,015
import Mathlib.Topology.Bases import Mathlib.Topology.DenseEmbedding #align_import topology.stone_cech from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" noncomputable section open Filter Set open Topology universe u v section Ultrafilter def ultrafilterBasis (α : Type u) : Set ...
Mathlib/Topology/StoneCech.lean
58
62
theorem ultrafilter_isClosed_basic (s : Set α) : IsClosed { u : Ultrafilter α | s ∈ u } := by
rw [← isOpen_compl_iff] convert ultrafilter_isOpen_basic sᶜ using 1 ext u exact Ultrafilter.compl_mem_iff_not_mem.symm
1,016
import Mathlib.Topology.Bases import Mathlib.Topology.DenseEmbedding #align_import topology.stone_cech from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" noncomputable section open Filter Set open Topology universe u v section Ultrafilter def ultrafilterBasis (α : Type u) : Set ...
Mathlib/Topology/StoneCech.lean
67
77
theorem ultrafilter_converges_iff {u : Ultrafilter (Ultrafilter α)} {x : Ultrafilter α} : ↑u ≤ 𝓝 x ↔ x = joinM u := by
rw [eq_comm, ← Ultrafilter.coe_le_coe] change ↑u ≤ 𝓝 x ↔ ∀ s ∈ x, { v : Ultrafilter α | s ∈ v } ∈ u simp only [TopologicalSpace.nhds_generateFrom, le_iInf_iff, ultrafilterBasis, le_principal_iff, mem_setOf_eq] constructor · intro h a ha exact h _ ⟨ha, a, rfl⟩ · rintro h a ⟨xi, a, rfl⟩ exact h ...
1,016
import Mathlib.Topology.Bases import Mathlib.Topology.DenseEmbedding #align_import topology.stone_cech from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" noncomputable section open Filter Set open Topology universe u v section Ultrafilter def ultrafilterBasis (α : Type u) : Set ...
Mathlib/Topology/StoneCech.lean
110
117
theorem ultrafilter_comap_pure_nhds (b : Ultrafilter α) : comap pure (𝓝 b) ≤ b := by
rw [TopologicalSpace.nhds_generateFrom] simp only [comap_iInf, comap_principal] intro s hs rw [← le_principal_iff] refine iInf_le_of_le { u | s ∈ u } ?_ refine iInf_le_of_le ⟨hs, ⟨s, rfl⟩⟩ ?_ exact principal_mono.2 fun a => id
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import Mathlib.Topology.Bases import Mathlib.Topology.DenseEmbedding #align_import topology.stone_cech from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" noncomputable section open Filter Set open Topology universe u v section Ultrafilter def ultrafilterBasis (α : Type u) : Set ...
Mathlib/Topology/StoneCech.lean
122
126
theorem ultrafilter_pure_injective : Function.Injective (pure : α → Ultrafilter α) := by
intro x y h have : {x} ∈ (pure x : Ultrafilter α) := singleton_mem_pure rw [h] at this exact (mem_singleton_iff.mp (mem_pure.mp this)).symm
1,016
import Mathlib.Topology.Bases import Mathlib.Topology.DenseEmbedding #align_import topology.stone_cech from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" noncomputable section open Filter Set open Topology universe u v section Ultrafilter def ultrafilterBasis (α : Type u) : Set ...
Mathlib/Topology/StoneCech.lean
138
143
theorem induced_topology_pure : TopologicalSpace.induced (pure : α → Ultrafilter α) Ultrafilter.topologicalSpace = ⊥ := by
apply eq_bot_of_singletons_open intro x use { u : Ultrafilter α | {x} ∈ u }, ultrafilter_isOpen_basic _ simp
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import Mathlib.Topology.Separation #align_import topology.sober from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" open Set variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] section genericPoint def IsGenericPoint (x : α) (S : Set α) : Prop := closure ({x} : Set α)...
Mathlib/Topology/Sober.lean
53
54
theorem isGenericPoint_iff_specializes : IsGenericPoint x S ↔ ∀ y, x ⤳ y ↔ y ∈ S := by
simp only [specializes_iff_mem_closure, IsGenericPoint, Set.ext_iff]
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import Mathlib.Topology.Separation #align_import topology.sober from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" open Set variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] section genericPoint def IsGenericPoint (x : α) (S : Set α) : Prop := closure ({x} : Set α)...
Mathlib/Topology/Sober.lean
92
93
theorem disjoint_iff (h : IsGenericPoint x S) (hU : IsOpen U) : Disjoint S U ↔ x ∉ U := by
rw [h.mem_open_set_iff hU, ← not_disjoint_iff_nonempty_inter, Classical.not_not]
1,017
import Mathlib.Topology.Separation #align_import topology.sober from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" open Set variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] section genericPoint def IsGenericPoint (x : α) (S : Set α) : Prop := closure ({x} : Set α)...
Mathlib/Topology/Sober.lean
96
97
theorem mem_closed_set_iff (h : IsGenericPoint x S) (hZ : IsClosed Z) : x ∈ Z ↔ S ⊆ Z := by
rw [← h.def, hZ.closure_subset_iff, singleton_subset_iff]
1,017
import Mathlib.Topology.Separation #align_import topology.sober from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" open Set variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] section genericPoint def IsGenericPoint (x : α) (S : Set α) : Prop := closure ({x} : Set α)...
Mathlib/Topology/Sober.lean
107
111
theorem isGenericPoint_iff_forall_closed (hS : IsClosed S) (hxS : x ∈ S) : IsGenericPoint x S ↔ ∀ Z : Set α, IsClosed Z → x ∈ Z → S ⊆ Z := by
have : closure {x} ⊆ S := closure_minimal (singleton_subset_iff.2 hxS) hS simp_rw [IsGenericPoint, subset_antisymm_iff, this, true_and_iff, closure, subset_sInter_iff, mem_setOf_eq, and_imp, singleton_subset_iff]
1,017
import Mathlib.Topology.Separation #align_import topology.sober from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977" open Set variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] section genericPoint def IsGenericPoint (x : α) (S : Set α) : Prop := closure ({x} : Set α)...
Mathlib/Topology/Sober.lean
148
150
theorem genericPoint_spec [QuasiSober α] [IrreducibleSpace α] : IsGenericPoint (genericPoint α) ⊤ := by
simpa using (IrreducibleSpace.isIrreducible_univ α).genericPoint_spec
1,017
import Mathlib.Algebra.GroupWithZero.Indicator import Mathlib.Algebra.Module.Basic import Mathlib.Topology.Separation #align_import topology.support from "leanprover-community/mathlib"@"d90e4e186f1d18e375dcd4e5b5f6364b01cb3e46" open Function Set Filter Topology variable {X α α' β γ δ M E R : Type*} section One ...
Mathlib/Topology/Support.lean
63
64
theorem mulTSupport_eq_empty_iff {f : X → α} : mulTSupport f = ∅ ↔ f = 1 := by
rw [mulTSupport, closure_empty_iff, mulSupport_eq_empty_iff]
1,018
import Mathlib.Topology.Separation import Mathlib.Topology.NoetherianSpace #align_import topology.quasi_separated from "leanprover-community/mathlib"@"5dc6092d09e5e489106865241986f7f2ad28d4c8" open TopologicalSpace variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] {f : α → β} def IsQuasiSeparate...
Mathlib/Topology/QuasiSeparated.lean
53
56
theorem isQuasiSeparated_univ_iff {α : Type*} [TopologicalSpace α] : IsQuasiSeparated (Set.univ : Set α) ↔ QuasiSeparatedSpace α := by
rw [quasiSeparatedSpace_iff] simp [IsQuasiSeparated]
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import Mathlib.Topology.Separation import Mathlib.Topology.NoetherianSpace #align_import topology.quasi_separated from "leanprover-community/mathlib"@"5dc6092d09e5e489106865241986f7f2ad28d4c8" open TopologicalSpace variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] {f : α → β} def IsQuasiSeparate...
Mathlib/Topology/QuasiSeparated.lean
64
86
theorem IsQuasiSeparated.image_of_embedding {s : Set α} (H : IsQuasiSeparated s) (h : Embedding f) : IsQuasiSeparated (f '' s) := by
intro U V hU hU' hU'' hV hV' hV'' convert (H (f ⁻¹' U) (f ⁻¹' V) ?_ (h.continuous.1 _ hU') ?_ ?_ (h.continuous.1 _ hV') ?_).image h.continuous · symm rw [← Set.preimage_inter, Set.image_preimage_eq_inter_range, Set.inter_eq_left] exact Set.inter_subset_left.trans (hU.trans (Set.image_subset_ran...
1,019
import Mathlib.Topology.Separation import Mathlib.Topology.NoetherianSpace #align_import topology.quasi_separated from "leanprover-community/mathlib"@"5dc6092d09e5e489106865241986f7f2ad28d4c8" open TopologicalSpace variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] {f : α → β} def IsQuasiSeparate...
Mathlib/Topology/QuasiSeparated.lean
89
96
theorem OpenEmbedding.isQuasiSeparated_iff (h : OpenEmbedding f) {s : Set α} : IsQuasiSeparated s ↔ IsQuasiSeparated (f '' s) := by
refine ⟨fun hs => hs.image_of_embedding h.toEmbedding, ?_⟩ intro H U V hU hU' hU'' hV hV' hV'' rw [h.toEmbedding.isCompact_iff, Set.image_inter h.inj] exact H (f '' U) (f '' V) (Set.image_subset _ hU) (h.isOpenMap _ hU') (hU''.image h.continuous) (Set.image_subset _ hV) (h.isOpenMap _ hV') (hV''.imag...
1,019
import Mathlib.Topology.Separation import Mathlib.Topology.NoetherianSpace #align_import topology.quasi_separated from "leanprover-community/mathlib"@"5dc6092d09e5e489106865241986f7f2ad28d4c8" open TopologicalSpace variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] {f : α → β} def IsQuasiSeparate...
Mathlib/Topology/QuasiSeparated.lean
99
103
theorem isQuasiSeparated_iff_quasiSeparatedSpace (s : Set α) (hs : IsOpen s) : IsQuasiSeparated s ↔ QuasiSeparatedSpace s := by
rw [← isQuasiSeparated_univ_iff] convert (hs.openEmbedding_subtype_val.isQuasiSeparated_iff (s := Set.univ)).symm simp
1,019
import Mathlib.Topology.Separation import Mathlib.Topology.NoetherianSpace #align_import topology.quasi_separated from "leanprover-community/mathlib"@"5dc6092d09e5e489106865241986f7f2ad28d4c8" open TopologicalSpace variable {α β : Type*} [TopologicalSpace α] [TopologicalSpace β] {f : α → β} def IsQuasiSeparate...
Mathlib/Topology/QuasiSeparated.lean
106
109
theorem IsQuasiSeparated.of_subset {s t : Set α} (ht : IsQuasiSeparated t) (h : s ⊆ t) : IsQuasiSeparated s := by
intro U V hU hU' hU'' hV hV' hV'' exact ht U V (hU.trans h) hU' hU'' (hV.trans h) hV' hV''
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import Mathlib.Topology.Sets.Closeds import Mathlib.Topology.QuasiSeparated #align_import topology.sets.compacts from "leanprover-community/mathlib"@"8c1b484d6a214e059531e22f1be9898ed6c1fd47" open Set variable {α β γ : Type*} [TopologicalSpace α] [TopologicalSpace β] [TopologicalSpace γ] namespace TopologicalSp...
Mathlib/Topology/Sets/Compacts.lean
125
129
theorem coe_finset_sup {ι : Type*} {s : Finset ι} {f : ι → Compacts α} : (↑(s.sup f) : Set α) = s.sup fun i => ↑(f i) := by
refine Finset.cons_induction_on s rfl fun a s _ h => ?_ simp_rw [Finset.sup_cons, coe_sup, sup_eq_union] congr
1,020
import Mathlib.AlgebraicGeometry.Morphisms.QuasiCompact import Mathlib.Topology.QuasiSeparated #align_import algebraic_geometry.morphisms.quasi_separated from "leanprover-community/mathlib"@"1a51edf13debfcbe223fa06b1cb353b9ed9751cc" noncomputable section open CategoryTheory CategoryTheory.Limits Opposite Topolog...
Mathlib/AlgebraicGeometry/Morphisms/QuasiSeparated.lean
57
83
theorem quasiSeparatedSpace_iff_affine (X : Scheme) : QuasiSeparatedSpace X.carrier ↔ ∀ U V : X.affineOpens, IsCompact (U ∩ V : Set X.carrier) := by
rw [quasiSeparatedSpace_iff] constructor · intro H U V; exact H U V U.1.2 U.2.isCompact V.1.2 V.2.isCompact · intro H suffices ∀ (U : Opens X.carrier) (_ : IsCompact U.1) (V : Opens X.carrier) (_ : IsCompact V.1), IsCompact (U ⊓ V).1 by intro U V hU hU' hV hV'; exact this ⟨U, hU⟩ hU' ⟨V...
1,021
import Mathlib.AlgebraicGeometry.Morphisms.QuasiCompact import Mathlib.Topology.QuasiSeparated #align_import algebraic_geometry.morphisms.quasi_separated from "leanprover-community/mathlib"@"1a51edf13debfcbe223fa06b1cb353b9ed9751cc" noncomputable section open CategoryTheory CategoryTheory.Limits Opposite Topolog...
Mathlib/AlgebraicGeometry/Morphisms/QuasiSeparated.lean
86
114
theorem quasi_compact_affineProperty_iff_quasiSeparatedSpace {X Y : Scheme} [IsAffine Y] (f : X ⟶ Y) : QuasiCompact.affineProperty.diagonal f ↔ QuasiSeparatedSpace X.carrier := by
delta AffineTargetMorphismProperty.diagonal rw [quasiSeparatedSpace_iff_affine] constructor · intro H U V haveI : IsAffine _ := U.2 haveI : IsAffine _ := V.2 let g : pullback (X.ofRestrict U.1.openEmbedding) (X.ofRestrict V.1.openEmbedding) ⟶ X := pullback.fst ≫ X.ofRestrict _ -- Porting ...
1,021
import Mathlib.AlgebraicGeometry.Morphisms.QuasiCompact import Mathlib.Topology.QuasiSeparated #align_import algebraic_geometry.morphisms.quasi_separated from "leanprover-community/mathlib"@"1a51edf13debfcbe223fa06b1cb353b9ed9751cc" noncomputable section open CategoryTheory CategoryTheory.Limits Opposite Topolog...
Mathlib/AlgebraicGeometry/Morphisms/QuasiSeparated.lean
117
118
theorem quasiSeparated_eq_diagonal_is_quasiCompact : @QuasiSeparated = MorphismProperty.diagonal @QuasiCompact := by
ext; exact quasiSeparated_iff _
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import Mathlib.AlgebraicGeometry.Morphisms.QuasiCompact import Mathlib.Topology.QuasiSeparated #align_import algebraic_geometry.morphisms.quasi_separated from "leanprover-community/mathlib"@"1a51edf13debfcbe223fa06b1cb353b9ed9751cc" noncomputable section open CategoryTheory CategoryTheory.Limits Opposite Topolog...
Mathlib/AlgebraicGeometry/Morphisms/QuasiSeparated.lean
121
123
theorem quasi_compact_affineProperty_diagonal_eq : QuasiCompact.affineProperty.diagonal = QuasiSeparated.affineProperty := by
funext; rw [quasi_compact_affineProperty_iff_quasiSeparatedSpace]; rfl
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import Mathlib.AlgebraicGeometry.Morphisms.QuasiCompact import Mathlib.Topology.QuasiSeparated #align_import algebraic_geometry.morphisms.quasi_separated from "leanprover-community/mathlib"@"1a51edf13debfcbe223fa06b1cb353b9ed9751cc" noncomputable section open CategoryTheory CategoryTheory.Limits Opposite Topolog...
Mathlib/AlgebraicGeometry/Morphisms/QuasiSeparated.lean
126
130
theorem quasiSeparated_eq_affineProperty_diagonal : @QuasiSeparated = targetAffineLocally QuasiCompact.affineProperty.diagonal := by
rw [quasiSeparated_eq_diagonal_is_quasiCompact, quasiCompact_eq_affineProperty] exact diagonal_targetAffineLocally_eq_targetAffineLocally _ QuasiCompact.affineProperty_isLocal
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import Mathlib.AlgebraicGeometry.Morphisms.QuasiCompact import Mathlib.Topology.QuasiSeparated #align_import algebraic_geometry.morphisms.quasi_separated from "leanprover-community/mathlib"@"1a51edf13debfcbe223fa06b1cb353b9ed9751cc" noncomputable section open CategoryTheory CategoryTheory.Limits Opposite Topolog...
Mathlib/AlgebraicGeometry/Morphisms/QuasiSeparated.lean
133
135
theorem quasiSeparated_eq_affineProperty : @QuasiSeparated = targetAffineLocally QuasiSeparated.affineProperty := by
rw [quasiSeparated_eq_affineProperty_diagonal, quasi_compact_affineProperty_diagonal_eq]
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import Mathlib.Topology.Separation import Mathlib.Algebra.Group.Defs #align_import topology.algebra.semigroup from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514" @[to_additive "Any nonempty compact Hausdorff additive semigroup where right-addition is continuous contains an ...
Mathlib/Topology/Algebra/Semigroup.lean
27
72
theorem exists_idempotent_of_compact_t2_of_continuous_mul_left {M} [Nonempty M] [Semigroup M] [TopologicalSpace M] [CompactSpace M] [T2Space M] (continuous_mul_left : ∀ r : M, Continuous (· * r)) : ∃ m : M, m * m = m := by
/- We apply Zorn's lemma to the poset of nonempty closed subsemigroups of `M`. It will turn out that any minimal element is `{m}` for an idempotent `m : M`. -/ let S : Set (Set M) := { N | IsClosed N ∧ N.Nonempty ∧ ∀ (m) (_ : m ∈ N) (m') (_ : m' ∈ N), m * m' ∈ N } rsuffices ⟨N, ⟨N_closed, ⟨m, hm⟩, N_mul...
1,022
import Mathlib.Topology.Separation import Mathlib.Algebra.Group.Defs #align_import topology.algebra.semigroup from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514" @[to_additive "Any nonempty compact Hausdorff additive semigroup where right-addition is continuous contains an ...
Mathlib/Topology/Algebra/Semigroup.lean
82
95
theorem exists_idempotent_in_compact_subsemigroup {M} [Semigroup M] [TopologicalSpace M] [T2Space M] (continuous_mul_left : ∀ r : M, Continuous (· * r)) (s : Set M) (snemp : s.Nonempty) (s_compact : IsCompact s) (s_add : ∀ᵉ (x ∈ s) (y ∈ s), x * y ∈ s) : ∃ m ∈ s, m * m = m := by
let M' := { m // m ∈ s } letI : Semigroup M' := { mul := fun p q => ⟨p.1 * q.1, s_add _ p.2 _ q.2⟩ mul_assoc := fun p q r => Subtype.eq (mul_assoc _ _ _) } haveI : CompactSpace M' := isCompact_iff_compactSpace.mp s_compact haveI : Nonempty M' := nonempty_subtype.mpr snemp have : ∀ p : M', Continuou...
1,022
import Mathlib.Topology.StoneCech import Mathlib.Topology.Algebra.Semigroup import Mathlib.Data.Stream.Init #align_import combinatorics.hindman from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988" open Filter @[to_additive "Addition of ultrafilters given by `∀ᶠ m in U+V, p m ↔ ∀ᶠ...
Mathlib/Combinatorics/Hindman.lean
119
131
theorem FP.mul {M} [Semigroup M] {a : Stream' M} {m : M} (hm : m ∈ FP a) : ∃ n, ∀ m' ∈ FP (a.drop n), m * m' ∈ FP a := by
induction' hm with a a m hm ih a m hm ih · exact ⟨1, fun m hm => FP.cons a m hm⟩ · cases' ih with n hn use n + 1 intro m' hm' exact FP.tail _ _ (hn _ hm') · cases' ih with n hn use n + 1 intro m' hm' rw [mul_assoc] exact FP.cons _ _ (hn _ hm')
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import Mathlib.Topology.StoneCech import Mathlib.Topology.Algebra.Semigroup import Mathlib.Data.Stream.Init #align_import combinatorics.hindman from "leanprover-community/mathlib"@"dc6c365e751e34d100e80fe6e314c3c3e0fd2988" open Filter @[to_additive "Addition of ultrafilters given by `∀ᶠ m in U+V, p m ↔ ∀ᶠ...
Mathlib/Combinatorics/Hindman.lean
138
165
theorem exists_idempotent_ultrafilter_le_FP {M} [Semigroup M] (a : Stream' M) : ∃ U : Ultrafilter M, U * U = U ∧ ∀ᶠ m in U, m ∈ FP a := by
let S : Set (Ultrafilter M) := ⋂ n, { U | ∀ᶠ m in U, m ∈ FP (a.drop n) } have h := exists_idempotent_in_compact_subsemigroup ?_ S ?_ ?_ ?_ · rcases h with ⟨U, hU, U_idem⟩ refine ⟨U, U_idem, ?_⟩ convert Set.mem_iInter.mp hU 0 · exact Ultrafilter.continuous_mul_left · apply IsCompact.nonempty_iInter_of...
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import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α}
Mathlib/Topology/Perfect.lean
62
68
theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by
have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_principal_iff] exact mem_nhdsWithin_of_mem_nhds hU rw [AccPt, ← inf_principal, ← inf_assoc, inf_of_le_left this] exact h_acc
1,024
import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
87
88
theorem preperfect_iff_nhds : Preperfect C ↔ ∀ x ∈ C, ∀ U ∈ 𝓝 x, ∃ y ∈ U ∩ C, y ≠ x := by
simp only [Preperfect, accPt_iff_nhds]
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import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
111
115
theorem Preperfect.open_inter {U : Set α} (hC : Preperfect C) (hU : IsOpen U) : Preperfect (U ∩ C) := by
rintro x ⟨xU, xC⟩ apply (hC _ xC).nhds_inter exact hU.mem_nhds xU
1,024
import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
120
128
theorem Preperfect.perfect_closure (hC : Preperfect C) : Perfect (closure C) := by
constructor; · exact isClosed_closure intro x hx by_cases h : x ∈ C <;> apply AccPt.mono _ (principal_mono.mpr subset_closure) · exact hC _ h have : {x}ᶜ ∩ C = C := by simp [h] rw [AccPt, nhdsWithin, inf_assoc, inf_principal, this] rw [closure_eq_cluster_pts] at hx exact hx
1,024
import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
132
144
theorem preperfect_iff_perfect_closure [T1Space α] : Preperfect C ↔ Perfect (closure C) := by
constructor <;> intro h · exact h.perfect_closure intro x xC have H : AccPt x (𝓟 (closure C)) := h.acc _ (subset_closure xC) rw [accPt_iff_frequently] at * have : ∀ y, y ≠ x ∧ y ∈ closure C → ∃ᶠ z in 𝓝 y, z ≠ x ∧ z ∈ C := by rintro y ⟨hyx, yC⟩ simp only [← mem_compl_singleton_iff, and_comm, ← fre...
1,024
import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
147
153
theorem Perfect.closure_nhds_inter {U : Set α} (hC : Perfect C) (x : α) (xC : x ∈ C) (xU : x ∈ U) (Uop : IsOpen U) : Perfect (closure (U ∩ C)) ∧ (closure (U ∩ C)).Nonempty := by
constructor · apply Preperfect.perfect_closure exact hC.acc.open_inter Uop apply Nonempty.closure exact ⟨x, ⟨xU, xC⟩⟩
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import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
158
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theorem Perfect.splitting [T25Space α] (hC : Perfect C) (hnonempty : C.Nonempty) : ∃ C₀ C₁ : Set α, (Perfect C₀ ∧ C₀.Nonempty ∧ C₀ ⊆ C) ∧ (Perfect C₁ ∧ C₁.Nonempty ∧ C₁ ⊆ C) ∧ Disjoint C₀ C₁ := by
cases' hnonempty with y yC obtain ⟨x, xC, hxy⟩ : ∃ x ∈ C, x ≠ y := by have := hC.acc _ yC rw [accPt_iff_nhds] at this rcases this univ univ_mem with ⟨x, xC, hxy⟩ exact ⟨x, xC.2, hxy⟩ obtain ⟨U, xU, Uop, V, yV, Vop, hUV⟩ := exists_open_nhds_disjoint_closure hxy use closure (U ∩ C), closure (V ∩ ...
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import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
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theorem exists_countable_union_perfect_of_isClosed [SecondCountableTopology α] (hclosed : IsClosed C) : ∃ V D : Set α, V.Countable ∧ Perfect D ∧ C = V ∪ D := by
obtain ⟨b, bct, _, bbasis⟩ := TopologicalSpace.exists_countable_basis α let v := { U ∈ b | (U ∩ C).Countable } let V := ⋃ U ∈ v, U let D := C \ V have Vct : (V ∩ C).Countable := by simp only [V, iUnion_inter, mem_sep_iff] apply Countable.biUnion · exact Countable.mono inter_subset_left bct · ...
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import Mathlib.Topology.Separation open Topology Filter Set TopologicalSpace section Basic variable {α : Type*} [TopologicalSpace α] {C : Set α} theorem AccPt.nhds_inter {x : α} {U : Set α} (h_acc : AccPt x (𝓟 C)) (hU : U ∈ 𝓝 x) : AccPt x (𝓟 (U ∩ C)) := by have : 𝓝[≠] x ≤ 𝓟 U := by rw [le_princ...
Mathlib/Topology/Perfect.lean
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theorem exists_perfect_nonempty_of_isClosed_of_not_countable [SecondCountableTopology α] (hclosed : IsClosed C) (hunc : ¬C.Countable) : ∃ D : Set α, Perfect D ∧ D.Nonempty ∧ D ⊆ C := by
rcases exists_countable_union_perfect_of_isClosed hclosed with ⟨V, D, Vct, Dperf, VD⟩ refine ⟨D, ⟨Dperf, ?_⟩⟩ constructor · rw [nonempty_iff_ne_empty] by_contra h rw [h, union_empty] at VD rw [VD] at hunc contradiction rw [VD] exact subset_union_right
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import Mathlib.Topology.Connected.Basic open Set Topology universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section LocallyConnectedSpace class LocallyConnectedSpace (α : Type*) [TopologicalSpace α] : Prop where open_connected_basis : ∀ x,...
Mathlib/Topology/Connected/LocallyConnected.lean
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theorem locallyConnectedSpace_iff_open_connected_subsets : LocallyConnectedSpace α ↔ ∀ x, ∀ U ∈ 𝓝 x, ∃ V : Set α, V ⊆ U ∧ IsOpen V ∧ x ∈ V ∧ IsConnected V := by
simp_rw [locallyConnectedSpace_iff_open_connected_basis] refine forall_congr' fun _ => ?_ constructor · intro h U hU rcases h.mem_iff.mp hU with ⟨V, hV, hVU⟩ exact ⟨V, hVU, hV⟩ · exact fun h => ⟨fun U => ⟨fun hU => let ⟨V, hVU, hV⟩ := h U hU ⟨V, hV, hVU⟩, fun ⟨V, ⟨hV, hxV, _⟩, hVU⟩ => mem...
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import Mathlib.Topology.Connected.Basic open Set Topology universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section LocallyConnectedSpace class LocallyConnectedSpace (α : Type*) [TopologicalSpace α] : Prop where open_connected_basis : ∀ x,...
Mathlib/Topology/Connected/LocallyConnected.lean
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theorem connectedComponentIn_mem_nhds [LocallyConnectedSpace α] {F : Set α} {x : α} (h : F ∈ 𝓝 x) : connectedComponentIn F x ∈ 𝓝 x := by
rw [(LocallyConnectedSpace.open_connected_basis x).mem_iff] at h rcases h with ⟨s, ⟨h1s, hxs, h2s⟩, hsF⟩ exact mem_nhds_iff.mpr ⟨s, h2s.isPreconnected.subset_connectedComponentIn hxs hsF, h1s, hxs⟩
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import Mathlib.Topology.Connected.Basic open Set Topology universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section LocallyConnectedSpace class LocallyConnectedSpace (α : Type*) [TopologicalSpace α] : Prop where open_connected_basis : ∀ x,...
Mathlib/Topology/Connected/LocallyConnected.lean
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theorem isOpen_connectedComponent [LocallyConnectedSpace α] {x : α} : IsOpen (connectedComponent x) := by
rw [← connectedComponentIn_univ] exact isOpen_univ.connectedComponentIn
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import Mathlib.Topology.Connected.Basic open Set Topology universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section LocallyConnectedSpace class LocallyConnectedSpace (α : Type*) [TopologicalSpace α] : Prop where open_connected_basis : ∀ x,...
Mathlib/Topology/Connected/LocallyConnected.lean
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theorem locallyConnectedSpace_iff_connectedComponentIn_open : LocallyConnectedSpace α ↔ ∀ F : Set α, IsOpen F → ∀ x ∈ F, IsOpen (connectedComponentIn F x) := by
constructor · intro h exact fun F hF x _ => hF.connectedComponentIn · intro h rw [locallyConnectedSpace_iff_open_connected_subsets] refine fun x U hU => ⟨connectedComponentIn (interior U) x, (connectedComponentIn_subset _ _).trans interior_subset, h _ isOpen_interior x ?_, ...
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import Mathlib.Topology.Connected.Basic open Set Topology universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section LocallyConnectedSpace class LocallyConnectedSpace (α : Type*) [TopologicalSpace α] : Prop where open_connected_basis : ∀ x,...
Mathlib/Topology/Connected/LocallyConnected.lean
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theorem locallyConnectedSpace_iff_connected_subsets : LocallyConnectedSpace α ↔ ∀ (x : α), ∀ U ∈ 𝓝 x, ∃ V ∈ 𝓝 x, IsPreconnected V ∧ V ⊆ U := by
constructor · rw [locallyConnectedSpace_iff_open_connected_subsets] intro h x U hxU rcases h x U hxU with ⟨V, hVU, hV₁, hxV, hV₂⟩ exact ⟨V, hV₁.mem_nhds hxV, hV₂.isPreconnected, hVU⟩ · rw [locallyConnectedSpace_iff_connectedComponentIn_open] refine fun h U hU x _ => isOpen_iff_mem_nhds.mpr fun y ...
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import Mathlib.Topology.Connected.Basic open Set Topology universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section LocallyConnectedSpace class LocallyConnectedSpace (α : Type*) [TopologicalSpace α] : Prop where open_connected_basis : ∀ x,...
Mathlib/Topology/Connected/LocallyConnected.lean
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theorem locallyConnectedSpace_iff_connected_basis : LocallyConnectedSpace α ↔ ∀ x, (𝓝 x).HasBasis (fun s : Set α => s ∈ 𝓝 x ∧ IsPreconnected s) id := by
rw [locallyConnectedSpace_iff_connected_subsets] exact forall_congr' fun x => Filter.hasBasis_self.symm
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import Mathlib.Topology.Connected.Basic open Set Topology universe u v variable {α : Type u} {β : Type v} {ι : Type*} {π : ι → Type*} [TopologicalSpace α] {s t u v : Set α} section LocallyConnectedSpace class LocallyConnectedSpace (α : Type*) [TopologicalSpace α] : Prop where open_connected_basis : ∀ x,...
Mathlib/Topology/Connected/LocallyConnected.lean
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theorem locallyConnectedSpace_of_connected_bases {ι : Type*} (b : α → ι → Set α) (p : α → ι → Prop) (hbasis : ∀ x, (𝓝 x).HasBasis (p x) (b x)) (hconnected : ∀ x i, p x i → IsPreconnected (b x i)) : LocallyConnectedSpace α := by
rw [locallyConnectedSpace_iff_connected_basis] exact fun x => (hbasis x).to_hasBasis (fun i hi => ⟨b x i, ⟨(hbasis x).mem_of_mem hi, hconnected x i hi⟩, subset_rfl⟩) fun s hs => ⟨(hbasis x).index s hs.1, ⟨(hbasis x).property_index hs.1, (hbasis x).set_index_subset hs.1⟩⟩
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import Mathlib.Logic.Equiv.Fin import Mathlib.Topology.DenseEmbedding import Mathlib.Topology.Support import Mathlib.Topology.Connected.LocallyConnected #align_import topology.homeomorph from "leanprover-community/mathlib"@"4c3e1721c58ef9087bbc2c8c38b540f70eda2e53" open Set Filter open Topology variable {X : Typ...
Mathlib/Topology/Homeomorph.lean
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theorem self_trans_symm (h : X ≃ₜ Y) : h.trans h.symm = Homeomorph.refl X := by
ext apply symm_apply_apply
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