topology.extend_from | 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

b363547b

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

0a0ec350

bump to nightly-2023-09-24-06

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

5655435f

Diff

@@ -3,7 +3,7 @@ Copyright (c) 2020 Anatole Dedecker. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Patrick Massot, Anatole Dedecker
 -/
-import Mathbin.Topology.Separation
+import Topology.Separation
 
 #align_import topology.extend_from from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977"

0a0ec350

bump to nightly-2023-07-20-09

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

9c56d0dd

Diff

@@ -2,14 +2,11 @@
 Copyright (c) 2020 Anatole Dedecker. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Patrick Massot, Anatole Dedecker
-
-! This file was ported from Lean 3 source module topology.extend_from
-! leanprover-community/mathlib commit 0a0ec35061ed9960bf0e7ffb0335f44447b58977
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Topology.Separation
 
+#align_import topology.extend_from from "leanprover-community/mathlib"@"0a0ec35061ed9960bf0e7ffb0335f44447b58977"
+
 /-!
 # Extending a function from a subset

0a0ec350

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -47,12 +47,14 @@ def extendFrom (A : Set X) (f : X → Y) : X → Y := fun x => @limUnder _ ⟨f
 #align extend_from extendFrom
 -/
 
+#print tendsto_extendFrom /-
 /-- If `f` converges to some `y` as `x` tends to `x₀` within `A`,
 then `f` tends to `extend_from A f x` as `x` tends to `x₀`. -/
 theorem tendsto_extendFrom {A : Set X} {f : X → Y} {x : X} (h : ∃ y, Tendsto f (𝓝[A] x) (𝓝 y)) :
     Tendsto f (𝓝[A] x) (𝓝 <| extendFrom A f x) :=
   tendsto_nhds_limUnder h
 #align tendsto_extend_from tendsto_extendFrom
+-/
 
 #print extendFrom_eq /-
 theorem extendFrom_eq [T2Space Y] {A : Set X} {f : X → Y} {x : X} {y : Y} (hx : x ∈ closure A)

0a0ec350

bump to nightly-2023-05-28-18

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

8d353152

Diff

@@ -33,7 +33,7 @@ it suffices that `f` converges within `A` at any point of `B`, provided that
 
 noncomputable section
 
-open Topology
+open scoped Topology
 
 open Filter Set

0a0ec350

bump to nightly-2023-05-28-06

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

ba5d8b97

Diff

@@ -47,12 +47,6 @@ def extendFrom (A : Set X) (f : X → Y) : X → Y := fun x => @limUnder _ ⟨f
 #align extend_from extendFrom
 -/
 
-/- warning: tendsto_extend_from -> tendsto_extendFrom is a dubious translation:
-lean 3 declaration is
-  forall {X : Type.{u1}} {Y : Type.{u2}} [_inst_1 : TopologicalSpace.{u1} X] [_inst_2 : TopologicalSpace.{u2} Y] {A : Set.{u1} X} {f : X -> Y} {x : X}, (Exists.{succ u2} Y (fun (y : Y) => Filter.Tendsto.{u1, u2} X Y f (nhdsWithin.{u1} X _inst_1 x A) (nhds.{u2} Y _inst_2 y))) -> (Filter.Tendsto.{u1, u2} X Y f (nhdsWithin.{u1} X _inst_1 x A) (nhds.{u2} Y _inst_2 (extendFrom.{u1, u2} X Y _inst_1 _inst_2 A f x)))
-but is expected to have type
-  forall {X : Type.{u2}} {Y : Type.{u1}} [_inst_1 : TopologicalSpace.{u2} X] [_inst_2 : TopologicalSpace.{u1} Y] {A : Set.{u2} X} {f : X -> Y} {x : X}, (Exists.{succ u1} Y (fun (y : Y) => Filter.Tendsto.{u2, u1} X Y f (nhdsWithin.{u2} X _inst_1 x A) (nhds.{u1} Y _inst_2 y))) -> (Filter.Tendsto.{u2, u1} X Y f (nhdsWithin.{u2} X _inst_1 x A) (nhds.{u1} Y _inst_2 (extendFrom.{u2, u1} X Y _inst_1 _inst_2 A f x)))
-Case conversion may be inaccurate. Consider using '#align tendsto_extend_from tendsto_extendFromₓ'. -/
 /-- If `f` converges to some `y` as `x` tends to `x₀` within `A`,
 then `f` tends to `extend_from A f x` as `x` tends to `x₀`. -/
 theorem tendsto_extendFrom {A : Set X} {f : X → Y} {x : X} (h : ∃ y, Tendsto f (𝓝[A] x) (𝓝 y)) :

0a0ec350

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

b363547b

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

@@ -71,8 +71,8 @@ theorem continuousOn_extendFrom [RegularSpace Y] {f : X → Y} {A B : Set X} (hB
     have := tendsto_extendFrom (hf x x_in)
     rcases (nhdsWithin_basis_open x A).tendsto_left_iff.mp this V' V'_in with ⟨V, ⟨hxV, V_op⟩, hV⟩
     exact ⟨V, IsOpen.mem_nhds V_op hxV, V_op, hV⟩
-  suffices : ∀ y ∈ V ∩ B, φ y ∈ V'
-  exact mem_of_superset (inter_mem_inf V_in <| mem_principal_self B) this
+  suffices ∀ y ∈ V ∩ B, φ y ∈ V' from
+    mem_of_superset (inter_mem_inf V_in <| mem_principal_self B) this
   rintro y ⟨hyV, hyB⟩
   haveI := mem_closure_iff_nhdsWithin_neBot.mp (hB hyB)
   have limy : Tendsto f (𝓝[A] y) (𝓝 <| φ y) := tendsto_extendFrom (hf y hyB)

b363547b

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

@@ -31,7 +31,7 @@ open Topology
 
 open Filter Set
 
-variable {X Y : Type _} [TopologicalSpace X] [TopologicalSpace Y]
+variable {X Y : Type*} [TopologicalSpace X] [TopologicalSpace Y]
 
 /-- Extend a function from a set `A`. The resulting function `g` is such that
 at any `x₀`, if `f` converges to some `y` as `x` tends to `x₀` within `A`,

b363547b

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

@@ -2,14 +2,11 @@
 Copyright (c) 2020 Anatole Dedecker. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Patrick Massot, Anatole Dedecker
-
-! This file was ported from Lean 3 source module topology.extend_from
-! leanprover-community/mathlib commit b363547b3113d350d053abdf2884e9850a56b205
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Topology.Separation
 
+#align_import topology.extend_from from "leanprover-community/mathlib"@"b363547b3113d350d053abdf2884e9850a56b205"
+
 /-!
 # Extending a function from a subset

b363547b

chore: fix many typos (#4535)

Run codespell Mathlib and keep some suggestions.

92f5c622

Diff

@@ -17,7 +17,7 @@ The main definition of this file is `extendFrom A f` where `f : X → Y`
 and `A : Set X`. This defines a new function `g : X → Y` which maps any
 `x₀ : X` to the limit of `f` as `x` tends to `x₀`, if such a limit exists.
 
-This is analoguous to the way `DenseInducing.extend` "extends" a function
+This is analogous to the way `DenseInducing.extend` "extends" a function
 `f : X → Z` to a function `g : Y → Z` along a dense inducing `i : X → Y`.
 
 The main theorem we prove about this definition is `continuousOn_extendFrom`

b363547b

feat: port Topology.ExtendFrom (#2055)

3016c86f

`topology.extend_from` ⟷ `Mathlib.Topology.ExtendFrom`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 8 + 303

topology.extend_from ⟷ Mathlib.Topology.ExtendFrom

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 8 + 303

`topology.extend_from` ⟷ `Mathlib.Topology.ExtendFrom`