category_theory.limits.filtered | 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

e4ee4e30

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

832f7b91

bump to nightly-2024-04-06-08

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

e34029c9

Diff

@@ -3,7 +3,7 @@ Copyright (c) 2022 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
 -/
-import CategoryTheory.Filtered
+import CategoryTheory.Filtered.Basic
 import CategoryTheory.Limits.HasLimits
 
 #align_import category_theory.limits.filtered from "leanprover-community/mathlib"@"832f7b9162039c28b9361289c8681f155cae758f"

832f7b91

bump to nightly-2023-09-24-06

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

5655435f

Diff

@@ -3,8 +3,8 @@ Copyright (c) 2022 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
 -/
-import Mathbin.CategoryTheory.Filtered
-import Mathbin.CategoryTheory.Limits.HasLimits
+import CategoryTheory.Filtered
+import CategoryTheory.Limits.HasLimits
 
 #align_import category_theory.limits.filtered from "leanprover-community/mathlib"@"832f7b9162039c28b9361289c8681f155cae758f"

832f7b91

bump to nightly-2023-07-20-09

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

9c56d0dd

Diff

@@ -2,15 +2,12 @@
 Copyright (c) 2022 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
-
-! This file was ported from Lean 3 source module category_theory.limits.filtered
-! leanprover-community/mathlib commit 832f7b9162039c28b9361289c8681f155cae758f
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.CategoryTheory.Filtered
 import Mathbin.CategoryTheory.Limits.HasLimits
 
+#align_import category_theory.limits.filtered from "leanprover-community/mathlib"@"832f7b9162039c28b9361289c8681f155cae758f"
+
 /-!
 # Possession of filtered colimits

832f7b91

bump to nightly-2023-03-03-22

mathlib commit https://github.com/leanprover-community/mathlib/commit/62e8311c791f02c47451bf14aa2501048e7c2f33

7fe4dd24

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
 
 ! This file was ported from Lean 3 source module category_theory.limits.filtered
-! leanprover-community/mathlib commit e4ee4e30418efcb8cf304ba76ad653aeec04ba6e
+! leanprover-community/mathlib commit 832f7b9162039c28b9361289c8681f155cae758f
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -13,6 +13,9 @@ import Mathbin.CategoryTheory.Limits.HasLimits
 
 /-!
 # Possession of filtered colimits
+
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
 -/

e4ee4e30

bump to nightly-2023-03-01-20

mathlib commit https://github.com/leanprover-community/mathlib/commit/4c586d291f189eecb9d00581aeb3dd998ac34442

20cadee0

Diff

@@ -30,29 +30,37 @@ section
 
 variable (C)
 
+#print CategoryTheory.Limits.HasCofilteredLimitsOfSize /-
 /-- Class for having all cofiltered limits of a given size. -/
 class HasCofilteredLimitsOfSize : Prop where
   HasLimitsOfShape : ∀ (I : Type w) [Category.{w'} I] [IsCofiltered I], HasLimitsOfShape I C
 #align category_theory.limits.has_cofiltered_limits_of_size CategoryTheory.Limits.HasCofilteredLimitsOfSize
+-/
 
+#print CategoryTheory.Limits.HasFilteredColimitsOfSize /-
 /-- Class for having all filtered colimits of a given size. -/
 class HasFilteredColimitsOfSize : Prop where
   HasColimitsOfShape : ∀ (I : Type w) [Category.{w'} I] [IsFiltered I], HasColimitsOfShape I C
 #align category_theory.limits.has_filtered_colimits_of_size CategoryTheory.Limits.HasFilteredColimitsOfSize
+-/
 
 end
 
+#print CategoryTheory.Limits.hasLimitsOfShape_of_has_cofiltered_limits /-
 instance (priority := 100) hasLimitsOfShape_of_has_cofiltered_limits
     [HasCofilteredLimitsOfSize.{w', w} C] (I : Type w) [Category.{w'} I] [IsCofiltered I] :
     HasLimitsOfShape I C :=
   HasCofilteredLimitsOfSize.hasLimitsOfShape _
 #align category_theory.limits.has_limits_of_shape_of_has_cofiltered_limits CategoryTheory.Limits.hasLimitsOfShape_of_has_cofiltered_limits
+-/
 
+#print CategoryTheory.Limits.hasColimitsOfShape_of_has_filtered_colimits /-
 instance (priority := 100) hasColimitsOfShape_of_has_filtered_colimits
     [HasFilteredColimitsOfSize.{w', w} C] (I : Type w) [Category.{w'} I] [IsFiltered I] :
     HasColimitsOfShape I C :=
   HasFilteredColimitsOfSize.hasColimitsOfShape _
 #align category_theory.limits.has_colimits_of_shape_of_has_filtered_colimits CategoryTheory.Limits.hasColimitsOfShape_of_has_filtered_colimits
+-/
 
 end CategoryTheory.Limits

e4ee4e30

bump to nightly-2023-02-27-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/eb0cb4511aaef0da2462207b67358a0e1fe1e2ee

91d8c210

Diff

@@ -42,17 +42,17 @@ class HasFilteredColimitsOfSize : Prop where
 
 end
 
-instance (priority := 100) hasLimitsOfShapeOfHasCofilteredLimits
+instance (priority := 100) hasLimitsOfShape_of_has_cofiltered_limits
     [HasCofilteredLimitsOfSize.{w', w} C] (I : Type w) [Category.{w'} I] [IsCofiltered I] :
     HasLimitsOfShape I C :=
   HasCofilteredLimitsOfSize.hasLimitsOfShape _
-#align category_theory.limits.has_limits_of_shape_of_has_cofiltered_limits CategoryTheory.Limits.hasLimitsOfShapeOfHasCofilteredLimits
+#align category_theory.limits.has_limits_of_shape_of_has_cofiltered_limits CategoryTheory.Limits.hasLimitsOfShape_of_has_cofiltered_limits
 
-instance (priority := 100) hasColimitsOfShapeOfHasFilteredColimits
+instance (priority := 100) hasColimitsOfShape_of_has_filtered_colimits
     [HasFilteredColimitsOfSize.{w', w} C] (I : Type w) [Category.{w'} I] [IsFiltered I] :
     HasColimitsOfShape I C :=
   HasFilteredColimitsOfSize.hasColimitsOfShape _
-#align category_theory.limits.has_colimits_of_shape_of_has_filtered_colimits CategoryTheory.Limits.hasColimitsOfShapeOfHasFilteredColimits
+#align category_theory.limits.has_colimits_of_shape_of_has_filtered_colimits CategoryTheory.Limits.hasColimitsOfShape_of_has_filtered_colimits
 
 end CategoryTheory.Limits

e4ee4e30

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

e4ee4e30

feat: existence of a limit in a concrete category implies smallness (#11625)

In this PR, it is shown that if a functor G : J ⥤ C to a concrete category has a limit and that forget C is corepresentable, then G ⋙ forget C).sections is small. As the corepresentability property holds in many concrete categories (e.g. groups, abelian groups) and that we already know since #11420 that limits exist under the smallness assumption in such categories, then this lemma may be used in future PR in order to show that usual forgetful functors preserve all limits (regardless of universe assumptions). This shall be convenient in the development of sheaves of modules.

In this PR, universes assumptions have also been generalized in the file Limits.Yoneda. In order to do this, a small refactor of the file Limits.Types was necessary. This introduces bijections like compCoyonedaSectionsEquiv (F : J ⥤ C) (X : C) : (F ⋙ coyoneda.obj (op X)).sections ≃ ((const J).obj X ⟶ F) with general universe parameters. In order to reduce imports in Limits.Yoneda, part of the file Limits.Types was moved to a new file Limits.TypesFiltered.

Co-authored-by: Joël Riou <joel.riou@universite-paris-saclay.fr>

3cb545c7

Diff

@@ -3,6 +3,7 @@ Copyright (c) 2022 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
 -/
+import Mathlib.CategoryTheory.Filtered.Basic
 import Mathlib.CategoryTheory.Limits.HasLimits
 import Mathlib.CategoryTheory.Limits.Types

e4ee4e30

feat: another characterization of filtered categories in terms of type-valued limits (#10665)

0b055722

Diff

@@ -3,13 +3,18 @@ Copyright (c) 2022 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
 -/
-import Mathlib.CategoryTheory.Filtered.Basic
 import Mathlib.CategoryTheory.Limits.HasLimits
+import Mathlib.CategoryTheory.Limits.Types
 
 #align_import category_theory.limits.filtered from "leanprover-community/mathlib"@"e4ee4e30418efcb8cf304ba76ad653aeec04ba6e"
 
 /-!
-# Possession of filtered colimits
+# Filtered categories and limits
+
+In this file , we show that `C` is filtered if and only if for every functor `F : J ⥤ C` from a
+finite category there is some `X : C` such that `lim Hom(F·, X)` is nonempty.
+
+Furthermore, we define the type classes `HasCofilteredLimitsOfSize` and `HasFilteredColimitsOfSize`.
 -/
 
 
@@ -21,7 +26,41 @@ open CategoryTheory
 
 variable {C : Type u} [Category.{v} C]
 
-namespace CategoryTheory.Limits
+namespace CategoryTheory
+
+section NonemptyLimit
+
+open CategoryTheory.Limits Opposite
+
+/-- `C` is filtered if and only if for every functor `F : J ⥤ C` from a finite category there is
+    some `X : C` such that `lim Hom(F·, X)` is nonempty.
+
+    Lemma 3.1.2 of [Kashiwara2006] -/
+theorem IsFiltered.iff_nonempty_limit : IsFiltered C ↔
+    ∀ {J : Type v} [SmallCategory J] [FinCategory J] (F : J ⥤ C),
+      ∃ (X : C), Nonempty (limit (F.op ⋙ yoneda.obj X)) := by
+  rw [IsFiltered.iff_cocone_nonempty.{v}]
+  refine ⟨fun h J _ _ F => ?_, fun h J _ _ F => ?_⟩
+  · obtain ⟨c⟩ := h F
+    exact ⟨c.pt, ⟨(limitCompYonedaIsoCocone F c.pt).inv c.ι⟩⟩
+  · obtain ⟨pt, ⟨ι⟩⟩ := h F
+    exact ⟨⟨pt, (limitCompYonedaIsoCocone F pt).hom ι⟩⟩
+
+/-- `C` is cofiltered if and only if for every functor `F : J ⥤ C` from a finite category there is
+    some `X : C` such that `lim Hom(X, F·)` is nonempty. -/
+theorem IsCofiltered.iff_nonempty_limit : IsCofiltered C ↔
+    ∀ {J : Type v} [SmallCategory J] [FinCategory J] (F : J ⥤ C),
+      ∃ (X : C), Nonempty (limit (F ⋙ coyoneda.obj (op X))) := by
+  rw [IsCofiltered.iff_cone_nonempty.{v}]
+  refine ⟨fun h J _ _ F => ?_, fun h J _ _ F => ?_⟩
+  · obtain ⟨c⟩ := h F
+    exact ⟨c.pt, ⟨(limitCompCoyonedaIsoCone F c.pt).inv c.π⟩⟩
+  · obtain ⟨pt, ⟨π⟩⟩ := h F
+    exact ⟨⟨pt, (limitCompCoyonedaIsoCone F pt).hom π⟩⟩
+
+end NonemptyLimit
+
+namespace Limits
 
 section
 
@@ -55,4 +94,6 @@ instance (priority := 100) hasColimitsOfShape_of_has_filtered_colimits
   HasFilteredColimitsOfSize.HasColimitsOfShape _
 #align category_theory.limits.has_colimits_of_shape_of_has_filtered_colimits CategoryTheory.Limits.hasColimitsOfShape_of_has_filtered_colimits
 
-end CategoryTheory.Limits
+end Limits
+
+end CategoryTheory

e4ee4e30

feat: a functor from a small category to a filtered category factors through a small filtered category (#6212)

a384f1b2

Diff

@@ -3,7 +3,7 @@ Copyright (c) 2022 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
 -/
-import Mathlib.CategoryTheory.Filtered
+import Mathlib.CategoryTheory.Filtered.Basic
 import Mathlib.CategoryTheory.Limits.HasLimits
 
 #align_import category_theory.limits.filtered from "leanprover-community/mathlib"@"e4ee4e30418efcb8cf304ba76ad653aeec04ba6e"

e4ee4e30

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

@@ -2,15 +2,12 @@
 Copyright (c) 2022 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
-
-! This file was ported from Lean 3 source module category_theory.limits.filtered
-! leanprover-community/mathlib commit e4ee4e30418efcb8cf304ba76ad653aeec04ba6e
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.CategoryTheory.Filtered
 import Mathlib.CategoryTheory.Limits.HasLimits
 
+#align_import category_theory.limits.filtered from "leanprover-community/mathlib"@"e4ee4e30418efcb8cf304ba76ad653aeec04ba6e"
+
 /-!
 # Possession of filtered colimits
 -/

e4ee4e30

refactor: make pp_with_univ be an attribute (#5633)

99ec98e2

Diff

@@ -31,21 +31,19 @@ section
 variable (C)
 
 /-- Class for having all cofiltered limits of a given size. -/
+@[pp_with_univ]
 class HasCofilteredLimitsOfSize : Prop where
   /-- For all filtered types of size `w`, we have limits -/
   HasLimitsOfShape : ∀ (I : Type w) [Category.{w'} I] [IsCofiltered I], HasLimitsOfShape I C
 #align category_theory.limits.has_cofiltered_limits_of_size CategoryTheory.Limits.HasCofilteredLimitsOfSize
 
-pp_with_univ HasCofilteredLimitsOfSize
-
 /-- Class for having all filtered colimits of a given size. -/
+@[pp_with_univ]
 class HasFilteredColimitsOfSize : Prop where
   /-- For all filtered types of a size `w`, we have colimits -/
   HasColimitsOfShape : ∀ (I : Type w) [Category.{w'} I] [IsFiltered I], HasColimitsOfShape I C
 #align category_theory.limits.has_filtered_colimits_of_size CategoryTheory.Limits.HasFilteredColimitsOfSize
 
-pp_with_univ HasFilteredColimitsOfSize
-
 end
 
 instance (priority := 100) hasLimitsOfShape_of_has_cofiltered_limits

e4ee4e30

feat: use pp_with_univ (#5622)

Certain definitions do nothing except change universes. We might as well have the pretty printer always show us these universes!

Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

c2826792

Diff

@@ -36,12 +36,16 @@ class HasCofilteredLimitsOfSize : Prop where
   HasLimitsOfShape : ∀ (I : Type w) [Category.{w'} I] [IsCofiltered I], HasLimitsOfShape I C
 #align category_theory.limits.has_cofiltered_limits_of_size CategoryTheory.Limits.HasCofilteredLimitsOfSize
 
+pp_with_univ HasCofilteredLimitsOfSize
+
 /-- Class for having all filtered colimits of a given size. -/
 class HasFilteredColimitsOfSize : Prop where
   /-- For all filtered types of a size `w`, we have colimits -/
   HasColimitsOfShape : ∀ (I : Type w) [Category.{w'} I] [IsFiltered I], HasColimitsOfShape I C
 #align category_theory.limits.has_filtered_colimits_of_size CategoryTheory.Limits.HasFilteredColimitsOfSize
 
+pp_with_univ HasFilteredColimitsOfSize
+
 end
 
 instance (priority := 100) hasLimitsOfShape_of_has_cofiltered_limits
@@ -57,4 +61,3 @@ instance (priority := 100) hasColimitsOfShape_of_has_filtered_colimits
 #align category_theory.limits.has_colimits_of_shape_of_has_filtered_colimits CategoryTheory.Limits.hasColimitsOfShape_of_has_filtered_colimits
 
 end CategoryTheory.Limits
-

e4ee4e30

feat: port CategoryTheory.Limits.Filtered (#2541)

6d1e96bc

`category_theory.limits.filtered` ⟷ `Mathlib.CategoryTheory.Limits.Filtered`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 2 + 214

category_theory.limits.filtered ⟷ Mathlib.CategoryTheory.Limits.Filtered

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 2 + 214

`category_theory.limits.filtered` ⟷ `Mathlib.CategoryTheory.Limits.Filtered`