topology.instances.discrete | Mathlib porting status

Changes since the initial port

The following section lists changes to this file in mathlib3 and mathlib4 that occured after the initial port. Most recent changes are shown first. Hovering over a commit will show all commits associated with the same mathlib3 commit.

Changes in mathlib3

bcfa7268

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

61b5e275

bump to nightly-2024-04-06-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

e34029c9

Diff

@@ -5,7 +5,7 @@ Authors: Rémy Degenne
 -/
 import Order.SuccPred.Basic
 import Topology.Order.Basic
-import Topology.MetricSpace.MetrizableUniformity
+import Topology.Metrizable.Uniformity
 
 #align_import topology.instances.discrete from "leanprover-community/mathlib"@"61b5e2755ccb464b68d05a9acf891ae04992d09d"

61b5e275

bump to nightly-2024-03-17-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

22f01ce4

Diff

@@ -38,8 +38,8 @@ instance (priority := 100) DiscreteTopology.firstCountableTopology [DiscreteTopo
 #align discrete_topology.first_countable_topology DiscreteTopology.firstCountableTopology
 -/
 
-#print DiscreteTopology.secondCountableTopology_of_encodable /-
-instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
+#print DiscreteTopology.secondCountableTopology_of_countable /-
+instance (priority := 100) DiscreteTopology.secondCountableTopology_of_countable
     [hd : DiscreteTopology α] [Encodable α] : SecondCountableTopology α :=
   haveI : ∀ i : α, second_countable_topology ↥({i} : Set α) := fun i =>
     {
@@ -47,7 +47,7 @@ instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
         ⟨{univ}, countable_singleton _, by simp only [eq_iff_true_of_subsingleton]⟩ }
   second_countable_topology_of_countable_cover (singletons_open_iff_discrete.mpr hd)
     (Union_of_singleton α)
-#align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_encodable
+#align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_countable
 -/
 
 #print bot_topologicalSpace_eq_generateFrom_of_pred_succOrder /-
@@ -94,23 +94,23 @@ theorem LinearOrder.bot_topologicalSpace_eq_generateFrom {α} [LinearOrder α] [
   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 
+  · 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_singleton_eq_inter 
+    · rw [ha_bot.Ici_eq] at h_singleton_eq_inter
       rw [h_singleton_eq_inter]
       apply isOpen_univ
-    · rw [isBot_iff_isMin] at ha_bot 
-      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter 
+    · rw [isBot_iff_isMin] at ha_bot
+      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter
       rw [h_singleton_eq_inter]
       exact is_open_generate_from_of_mem ⟨pred a, Or.inl rfl⟩
-  · rw [isTop_iff_isMax] at ha_top 
-    rw [← Iio_succ_of_not_is_max ha_top] at h_singleton_eq_inter 
+  · rw [isTop_iff_isMax] at ha_top
+    rw [← Iio_succ_of_not_is_max ha_top] at h_singleton_eq_inter
     by_cases ha_bot : IsBot a
-    · rw [ha_bot.Ici_eq, inter_univ] at h_singleton_eq_inter 
+    · rw [ha_bot.Ici_eq, inter_univ] at h_singleton_eq_inter
       rw [h_singleton_eq_inter]
       exact is_open_generate_from_of_mem ⟨succ a, Or.inr rfl⟩
-    · rw [isBot_iff_isMin] at ha_bot 
-      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter 
+    · rw [isBot_iff_isMin] at ha_bot
+      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter
       rw [h_singleton_eq_inter]
       apply IsOpen.inter
       · exact is_open_generate_from_of_mem ⟨succ a, Or.inr rfl⟩

61b5e275

bump to nightly-2023-09-24-06

mathlib commit https://github.com/leanprover-community/mathlib/commit/ce64cd319bb6b3e82f31c2d38e79080d377be451

5655435f

Diff

@@ -3,9 +3,9 @@ Copyright (c) 2022 Rémy Degenne. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Rémy Degenne
 -/
-import Mathbin.Order.SuccPred.Basic
-import Mathbin.Topology.Order.Basic
-import Mathbin.Topology.MetricSpace.MetrizableUniformity
+import Order.SuccPred.Basic
+import Topology.Order.Basic
+import Topology.MetricSpace.MetrizableUniformity
 
 #align_import topology.instances.discrete from "leanprover-community/mathlib"@"61b5e2755ccb464b68d05a9acf891ae04992d09d"

61b5e275

bump to nightly-2023-07-20-09

mathlib commit https://github.com/leanprover-community/mathlib/commit/8ea5598db6caeddde6cb734aa179cc2408dbd345

9c56d0dd

Diff

@@ -2,16 +2,13 @@
 Copyright (c) 2022 Rémy Degenne. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Rémy Degenne
-
-! This file was ported from Lean 3 source module topology.instances.discrete
-! leanprover-community/mathlib commit 61b5e2755ccb464b68d05a9acf891ae04992d09d
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Order.SuccPred.Basic
 import Mathbin.Topology.Order.Basic
 import Mathbin.Topology.MetricSpace.MetrizableUniformity
 
+#align_import topology.instances.discrete from "leanprover-community/mathlib"@"61b5e2755ccb464b68d05a9acf891ae04992d09d"
+
 /-!
 # Instances related to the discrete topology

61b5e275

bump to nightly-2023-06-13-21

mathlib commit https://github.com/leanprover-community/mathlib/commit/9fb8964792b4237dac6200193a0d533f1b3f7423

829520ac

Diff

@@ -53,6 +53,7 @@ instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
 #align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_encodable
 -/
 
+#print bot_topologicalSpace_eq_generateFrom_of_pred_succOrder /-
 theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder {α} [PartialOrder α] [PredOrder α]
     [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] :
     (⊥ : TopologicalSpace α) = generateFrom {s | ∃ a, s = Ioi a ∨ s = Iio a} :=
@@ -68,6 +69,7 @@ theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder {α} [PartialOrde
   · exact is_open_generate_from_of_mem ⟨succ a, Or.inr rfl⟩
   · exact is_open_generate_from_of_mem ⟨pred a, Or.inl rfl⟩
 #align bot_topological_space_eq_generate_from_of_pred_succ_order bot_topologicalSpace_eq_generateFrom_of_pred_succOrder
+-/
 
 #print discreteTopology_iff_orderTopology_of_pred_succ' /-
 theorem discreteTopology_iff_orderTopology_of_pred_succ' [PartialOrder α] [PredOrder α]
@@ -88,6 +90,7 @@ instance (priority := 100) DiscreteTopology.orderTopology_of_pred_succ' [h : Dis
 #align discrete_topology.order_topology_of_pred_succ' DiscreteTopology.orderTopology_of_pred_succ'
 -/
 
+#print LinearOrder.bot_topologicalSpace_eq_generateFrom /-
 theorem LinearOrder.bot_topologicalSpace_eq_generateFrom {α} [LinearOrder α] [PredOrder α]
     [SuccOrder α] : (⊥ : TopologicalSpace α) = generateFrom {s | ∃ a, s = Ioi a ∨ s = Iio a} :=
   by
@@ -116,6 +119,7 @@ theorem LinearOrder.bot_topologicalSpace_eq_generateFrom {α} [LinearOrder α] [
       · exact is_open_generate_from_of_mem ⟨succ a, Or.inr rfl⟩
       · exact is_open_generate_from_of_mem ⟨pred a, Or.inl rfl⟩
 #align linear_order.bot_topological_space_eq_generate_from LinearOrder.bot_topologicalSpace_eq_generateFrom
+-/
 
 #print discreteTopology_iff_orderTopology_of_pred_succ /-
 theorem discreteTopology_iff_orderTopology_of_pred_succ [LinearOrder α] [PredOrder α]

61b5e275

bump to nightly-2023-06-04-18

mathlib commit https://github.com/leanprover-community/mathlib/commit/5f25c089cb34db4db112556f23c50d12da81b297

3fb4268b

Diff

@@ -55,7 +55,7 @@ instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
 
 theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder {α} [PartialOrder α] [PredOrder α]
     [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] :
-    (⊥ : TopologicalSpace α) = generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a } :=
+    (⊥ : 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) :=
@@ -89,7 +89,7 @@ instance (priority := 100) DiscreteTopology.orderTopology_of_pred_succ' [h : Dis
 -/
 
 theorem LinearOrder.bot_topologicalSpace_eq_generateFrom {α} [LinearOrder α] [PredOrder α]
-    [SuccOrder α] : (⊥ : TopologicalSpace α) = generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a } :=
+    [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]

61b5e275

bump to nightly-2023-06-01-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/cca40788df1b8755d5baf17ab2f27dacc2e17acb

b9c87c70

Diff

@@ -94,23 +94,23 @@ theorem LinearOrder.bot_topologicalSpace_eq_generateFrom {α} [LinearOrder α] [
   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
+  · 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_singleton_eq_inter
+    · rw [ha_bot.Ici_eq] at h_singleton_eq_inter 
       rw [h_singleton_eq_inter]
       apply isOpen_univ
-    · rw [isBot_iff_isMin] at ha_bot
-      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter
+    · rw [isBot_iff_isMin] at ha_bot 
+      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter 
       rw [h_singleton_eq_inter]
       exact is_open_generate_from_of_mem ⟨pred a, Or.inl rfl⟩
-  · rw [isTop_iff_isMax] at ha_top
-    rw [← Iio_succ_of_not_is_max ha_top] at h_singleton_eq_inter
+  · rw [isTop_iff_isMax] at ha_top 
+    rw [← Iio_succ_of_not_is_max ha_top] at h_singleton_eq_inter 
     by_cases ha_bot : IsBot a
-    · rw [ha_bot.Ici_eq, inter_univ] at h_singleton_eq_inter
+    · rw [ha_bot.Ici_eq, inter_univ] at h_singleton_eq_inter 
       rw [h_singleton_eq_inter]
       exact is_open_generate_from_of_mem ⟨succ a, Or.inr rfl⟩
-    · rw [isBot_iff_isMin] at ha_bot
-      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter
+    · rw [isBot_iff_isMin] at ha_bot 
+      rw [← Ioi_pred_of_not_is_min ha_bot] at h_singleton_eq_inter 
       rw [h_singleton_eq_inter]
       apply IsOpen.inter
       · exact is_open_generate_from_of_mem ⟨succ a, Or.inr rfl⟩

61b5e275

bump to nightly-2023-06-01-04

mathlib commit https://github.com/leanprover-community/mathlib/commit/cca40788df1b8755d5baf17ab2f27dacc2e17acb

4d9eaa85

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Rémy Degenne
 
 ! This file was ported from Lean 3 source module topology.instances.discrete
-! leanprover-community/mathlib commit bcfa726826abd57587355b4b5b7e78ad6527b7e4
+! leanprover-community/mathlib commit 61b5e2755ccb464b68d05a9acf891ae04992d09d
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -15,6 +15,9 @@ import Mathbin.Topology.MetricSpace.MetrizableUniformity
 /-!
 # Instances related to the discrete topology
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 We prove that the discrete topology is
 * first-countable,
 * second-countable for an encodable type,
@@ -31,11 +34,14 @@ open Order Set TopologicalSpace Filter
 
 variable {α : Type _} [TopologicalSpace α]
 
+#print DiscreteTopology.firstCountableTopology /-
 instance (priority := 100) DiscreteTopology.firstCountableTopology [DiscreteTopology α] :
     FirstCountableTopology α
     where nhds_generated_countable := by rw [nhds_discrete]; exact is_countably_generated_pure
 #align discrete_topology.first_countable_topology DiscreteTopology.firstCountableTopology
+-/
 
+#print DiscreteTopology.secondCountableTopology_of_encodable /-
 instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
     [hd : DiscreteTopology α] [Encodable α] : SecondCountableTopology α :=
   haveI : ∀ i : α, second_countable_topology ↥({i} : Set α) := fun i =>
@@ -45,6 +51,7 @@ instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
   second_countable_topology_of_countable_cover (singletons_open_iff_discrete.mpr hd)
     (Union_of_singleton α)
 #align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_encodable
+-/
 
 theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder {α} [PartialOrder α] [PredOrder α]
     [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] :
@@ -62,6 +69,7 @@ theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder {α} [PartialOrde
   · exact is_open_generate_from_of_mem ⟨pred a, Or.inl rfl⟩
 #align bot_topological_space_eq_generate_from_of_pred_succ_order bot_topologicalSpace_eq_generateFrom_of_pred_succOrder
 
+#print discreteTopology_iff_orderTopology_of_pred_succ' /-
 theorem discreteTopology_iff_orderTopology_of_pred_succ' [PartialOrder α] [PredOrder α]
     [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] : DiscreteTopology α ↔ OrderTopology α :=
   by
@@ -71,11 +79,14 @@ theorem discreteTopology_iff_orderTopology_of_pred_succ' [PartialOrder α] [Pred
   · rw [h.topology_eq_generate_intervals]
     exact bot_topological_space_eq_generate_from_of_pred_succ_order.symm
 #align discrete_topology_iff_order_topology_of_pred_succ' discreteTopology_iff_orderTopology_of_pred_succ'
+-/
 
+#print DiscreteTopology.orderTopology_of_pred_succ' /-
 instance (priority := 100) DiscreteTopology.orderTopology_of_pred_succ' [h : DiscreteTopology α]
     [PartialOrder α] [PredOrder α] [SuccOrder α] [NoMinOrder α] [NoMaxOrder α] : OrderTopology α :=
   discreteTopology_iff_orderTopology_of_pred_succ'.1 h
 #align discrete_topology.order_topology_of_pred_succ' DiscreteTopology.orderTopology_of_pred_succ'
+-/
 
 theorem LinearOrder.bot_topologicalSpace_eq_generateFrom {α} [LinearOrder α] [PredOrder α]
     [SuccOrder α] : (⊥ : TopologicalSpace α) = generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a } :=
@@ -106,6 +117,7 @@ theorem LinearOrder.bot_topologicalSpace_eq_generateFrom {α} [LinearOrder α] [
       · exact is_open_generate_from_of_mem ⟨pred a, Or.inl rfl⟩
 #align linear_order.bot_topological_space_eq_generate_from LinearOrder.bot_topologicalSpace_eq_generateFrom
 
+#print discreteTopology_iff_orderTopology_of_pred_succ /-
 theorem discreteTopology_iff_orderTopology_of_pred_succ [LinearOrder α] [PredOrder α]
     [SuccOrder α] : DiscreteTopology α ↔ OrderTopology α :=
   by
@@ -115,15 +127,20 @@ theorem discreteTopology_iff_orderTopology_of_pred_succ [LinearOrder α] [PredOr
   · rw [h.topology_eq_generate_intervals]
     exact linear_order.bot_topological_space_eq_generate_from.symm
 #align discrete_topology_iff_order_topology_of_pred_succ discreteTopology_iff_orderTopology_of_pred_succ
+-/
 
+#print DiscreteTopology.orderTopology_of_pred_succ /-
 instance (priority := 100) DiscreteTopology.orderTopology_of_pred_succ [h : DiscreteTopology α]
     [LinearOrder α] [PredOrder α] [SuccOrder α] : OrderTopology α :=
   discreteTopology_iff_orderTopology_of_pred_succ.mp h
 #align discrete_topology.order_topology_of_pred_succ DiscreteTopology.orderTopology_of_pred_succ
+-/
 
+#print DiscreteTopology.metrizableSpace /-
 instance (priority := 100) DiscreteTopology.metrizableSpace [DiscreteTopology α] :
     MetrizableSpace α := by
   obtain rfl := DiscreteTopology.eq_bot α
   exact @UniformSpace.metrizableSpace α ⊥ (is_countably_generated_principal _) _
 #align discrete_topology.metrizable_space DiscreteTopology.metrizableSpace
+-/

bcfa7268

bump to nightly-2023-05-28-04

mathlib commit https://github.com/leanprover-community/mathlib/commit/917c3c072e487b3cccdbfeff17e75b40e45f66cb

6797a637

Diff

@@ -33,9 +33,7 @@ variable {α : Type _} [TopologicalSpace α]
 
 instance (priority := 100) DiscreteTopology.firstCountableTopology [DiscreteTopology α] :
     FirstCountableTopology α
-    where nhds_generated_countable := by
-    rw [nhds_discrete]
-    exact is_countably_generated_pure
+    where nhds_generated_countable := by rw [nhds_discrete]; exact is_countably_generated_pure
 #align discrete_topology.first_countable_topology DiscreteTopology.firstCountableTopology
 
 instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable

bcfa7268

bump to nightly-2023-02-21-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/bd9851ca476957ea4549eb19b40e7b5ade9428cc

1107b979

Changes in mathlib4

mathlib3

mathlib4

bcfa7268

chore(Topology/Instances/Discrete): merge 2 instances (#11296)

Prove DiscreteTopology.secondCountableTopology_of_countable directly, deprecate DiscreteTopology.secondCountableTopology_of_encodable.

69adfea7

Diff

@@ -33,18 +33,19 @@ instance (priority := 100) DiscreteTopology.firstCountableTopology [DiscreteTopo
   nhds_generated_countable := by rw [nhds_discrete]; exact isCountablyGenerated_pure
 #align discrete_topology.first_countable_topology DiscreteTopology.firstCountableTopology
 
-instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
-    [hd : DiscreteTopology α] [Encodable α] : SecondCountableTopology α :=
+instance (priority := 100) DiscreteTopology.secondCountableTopology_of_countable
+    [hd : DiscreteTopology α] [Countable α] : SecondCountableTopology α :=
   haveI : ∀ i : α, SecondCountableTopology (↥({i} : Set α)) := fun i =>
     { is_open_generated_countable :=
         ⟨{univ}, countable_singleton _, by simp only [eq_iff_true_of_subsingleton]⟩ }
   secondCountableTopology_of_countable_cover (singletons_open_iff_discrete.mpr hd)
     (iUnion_of_singleton α)
-#align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_encodable
+#align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_countable
 
-instance (priority := 100) DiscreteTopology.secondCountableTopology_of_countable {α : Type*}
+@[deprecated DiscreteTopology.secondCountableTopology_of_countable] -- 2024-03-11
+theorem DiscreteTopology.secondCountableTopology_of_encodable {α : Type*}
     [TopologicalSpace α] [DiscreteTopology α] [Countable α] : SecondCountableTopology α :=
-  @DiscreteTopology.secondCountableTopology_of_encodable _ _ _ (Encodable.ofCountable _)
+  DiscreteTopology.secondCountableTopology_of_countable
 #align discrete_topology.second_countable_topology_of_countable DiscreteTopology.secondCountableTopology_of_countable
 
 theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder [PartialOrder α] [PredOrder α]

bcfa7268

chore: remove stream-of-consciousness uses of have, replace and suffices (#10640)

No changes to tactic file, it's just boring fixes throughout the library.

This follows on from #6964.

Co-authored-by: sgouezel <sebastien.gouezel@univ-rennes1.fr> Co-authored-by: Eric Wieser <wieser.eric@gmail.com>

a13e8040

Diff

@@ -52,8 +52,8 @@ theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder [PartialOrder 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
-    · rw [h_singleton_eq_inter', ← Ioi_pred, ← Iio_succ]
+    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]
   letI := Preorder.topology α

bcfa7268

chore: move DiscreteTopology.secondCountableTopology_of_countable (#10615)

Implement a porting note to move this instance to a much more natural file.

369f8d74

Diff

@@ -42,6 +42,11 @@ instance (priority := 100) DiscreteTopology.secondCountableTopology_of_encodable
     (iUnion_of_singleton α)
 #align discrete_topology.second_countable_topology_of_encodable DiscreteTopology.secondCountableTopology_of_encodable
 
+instance (priority := 100) DiscreteTopology.secondCountableTopology_of_countable {α : Type*}
+    [TopologicalSpace α] [DiscreteTopology α] [Countable α] : SecondCountableTopology α :=
+  @DiscreteTopology.secondCountableTopology_of_encodable _ _ _ (Encodable.ofCountable _)
+#align discrete_topology.second_countable_topology_of_countable DiscreteTopology.secondCountableTopology_of_countable
+
 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

bcfa7268

chore(Topology): move some definitions to new files (#10151)

In some cases, the order of implicit arguments changed because now they appear in a different order in variables.

Also, some definitions used greek letters for topological spaces, changed to X/Y.

2e5d90d5

Diff

@@ -51,8 +51,8 @@ theorem bot_topologicalSpace_eq_generateFrom_of_pred_succOrder [PartialOrder α]
     · rw [h_singleton_eq_inter', ← Ioi_pred, ← Iio_succ]
     rw [inter_comm, Ici_inter_Iic, Icc_self a]
   rw [h_singleton_eq_inter]
-  -- Porting note: Specified instance for `IsOpen.inter` explicitly to fix an error.
-  apply @IsOpen.inter _ _ _ (generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a })
+  letI := Preorder.topology α
+  apply IsOpen.inter
   · exact isOpen_generateFrom_of_mem ⟨succ a, Or.inr rfl⟩
   · exact isOpen_generateFrom_of_mem ⟨pred a, Or.inl rfl⟩
 #align bot_topological_space_eq_generate_from_of_pred_succ_order bot_topologicalSpace_eq_generateFrom_of_pred_succOrder
@@ -96,7 +96,8 @@ theorem LinearOrder.bot_topologicalSpace_eq_generateFrom [LinearOrder α] [PredO
       rw [← Ioi_pred_of_not_isMin ha_bot] at h_singleton_eq_inter
       rw [h_singleton_eq_inter]
       -- Porting note: Specified instance for `IsOpen.inter` explicitly to fix an error.
-      apply @IsOpen.inter _ _ _ (generateFrom { s | ∃ a, s = Ioi a ∨ s = Iio a })
+      letI := Preorder.topology α
+      apply IsOpen.inter
       · exact isOpen_generateFrom_of_mem ⟨succ a, Or.inr rfl⟩
       · exact isOpen_generateFrom_of_mem ⟨pred a, Or.inl rfl⟩
 #align linear_order.bot_topological_space_eq_generate_from LinearOrder.bot_topologicalSpace_eq_generateFrom

bcfa7268

chore: split Topology.MetricSpace.Metrizable* (#7912)

Move

basic definitions to Topology.Metrizable.Basic,
Urysohn's metrization theorem to `Topology.Metrizable.Urysohns', and
metrizability of a uniform space with countably generated uniformity to Topology.Metrizable.Uniform.

The next step is to redefine Metrizable as "uniformizable with countably generated uniformity" and make this definition available much earlier.

442eef6f

Diff

@@ -5,7 +5,7 @@ Authors: Rémy Degenne
 -/
 import Mathlib.Order.SuccPred.Basic
 import Mathlib.Topology.Order.Basic
-import Mathlib.Topology.MetricSpace.MetrizableUniformity
+import Mathlib.Topology.Metrizable.Uniformity
 
 #align_import topology.instances.discrete from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4"

bcfa7268

chore: banish Type _ and Sort _ (#6499)

We remove all possible occurences of Type _ and Sort _ in favor of Type* and Sort*.

This has nice performance benefits.

32de3f67

Diff

@@ -26,7 +26,7 @@ and `OrderTopology ℕ` become available.
 
 open Order Set TopologicalSpace Filter
 
-variable {α : Type _} [TopologicalSpace α]
+variable {α : Type*} [TopologicalSpace α]
 
 instance (priority := 100) DiscreteTopology.firstCountableTopology [DiscreteTopology α] :
     FirstCountableTopology α where

bcfa7268

chore: script to replace headers with #align_import statements (#5979)

depends on: #5966

Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

89aa3a3b

Diff

@@ -2,16 +2,13 @@
 Copyright (c) 2022 Rémy Degenne. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Rémy Degenne
-
-! This file was ported from Lean 3 source module topology.instances.discrete
-! leanprover-community/mathlib commit bcfa726826abd57587355b4b5b7e78ad6527b7e4
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Order.SuccPred.Basic
 import Mathlib.Topology.Order.Basic
 import Mathlib.Topology.MetricSpace.MetrizableUniformity
 
+#align_import topology.instances.discrete from "leanprover-community/mathlib"@"bcfa726826abd57587355b4b5b7e78ad6527b7e4"
+
 /-!
 # Instances related to the discrete topology

bcfa7268

feat: port Topology.Instances.Discrete (#4479)

15f033db

`topology.instances.discrete` ⟷ `Mathlib.Topology.Instances.Discrete`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 10 + 690

topology.instances.discrete ⟷ Mathlib.Topology.Instances.Discrete

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 10 + 690

`topology.instances.discrete` ⟷ `Mathlib.Topology.Instances.Discrete`