category_theory.sites.pushforward | 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

e2e38c00

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

bd15ff41

bump to nightly-2024-04-14-09

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

f736ea6b

Diff

@@ -42,7 +42,8 @@ instance [HasLimits A] : CreatesLimits (sheafToPresheaf J A) :=
 -- The assumptions so that we have sheafification
 variable [ConcreteCategory.{v₁} A] [PreservesLimits (forget A)] [HasColimits A] [HasLimits A]
 
-variable [PreservesFilteredColimits (forget A)] [ReflectsIsomorphisms (forget A)]
+variable [PreservesFilteredColimits (forget A)]
+  [CategoryTheory.Functor.ReflectsIsomorphisms (forget A)]
 
 attribute [local instance] reflects_limits_of_reflects_isomorphisms

bd15ff41

bump to nightly-2024-01-11-06

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

c7c71e9e

Diff

@@ -54,7 +54,7 @@ instance {X : C} : IsCofiltered (J.cover X) :=
 same direction as `G`. -/
 @[simps]
 def Functor.sheafPullback (G : C ⥤ D) : Sheaf J A ⥤ Sheaf K A :=
-  sheafToPresheaf J A ⋙ lan G.op ⋙ presheafToSheaf K A
+  sheafToPresheaf J A ⋙ lan G.op ⋙ plusPlusSheaf K A
 #align category_theory.sites.pushforward CategoryTheory.Functor.sheafPullback
 -/
 
@@ -65,7 +65,7 @@ instance (G : C ⥤ D) [RepresentablyFlat G] :
   · infer_instance
   apply (config := { instances := false }) comp_preserves_finite_limits
   · apply CategoryTheory.lanPreservesFiniteLimitsOfFlat
-  · apply CategoryTheory.presheafToSheaf.Limits.preservesFiniteLimits.{u₁, v₁, v₁}
+  · apply CategoryTheory.plusPlusSheaf.Limits.preservesFiniteLimits.{u₁, v₁, v₁}
     infer_instance
 
 #print CategoryTheory.Functor.sheafAdjunctionContinuous /-
@@ -73,7 +73,7 @@ instance (G : C ⥤ D) [RepresentablyFlat G] :
 def Functor.sheafAdjunctionContinuous {G : C ⥤ D} (hG₁ : CompatiblePreserving K G)
     (hG₂ : CoverPreserving J K G) :
     Functor.sheafPullback A J K G ⊣ Functor.sheafPushforwardContinuous A hG₁ hG₂ :=
-  ((Lan.adjunction A G.op).comp (sheafificationAdjunction K A)).restrictFullyFaithful
+  ((Lan.adjunction A G.op).comp (plusPlusAdjunction K A)).restrictFullyFaithful
     (sheafToPresheaf J A) (𝟭 _)
     (NatIso.ofComponents (fun _ => Iso.refl _) fun _ _ _ =>
       (Category.comp_id _).trans (Category.id_comp _).symm)

bd15ff41

bump to nightly-2023-11-29-11

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

049e2cad

Diff

@@ -49,16 +49,17 @@ attribute [local instance] reflects_limits_of_reflects_isomorphisms
 instance {X : C} : IsCofiltered (J.cover X) :=
   inferInstance
 
-#print CategoryTheory.Sites.pushforward /-
+#print CategoryTheory.Functor.sheafPullback /-
 /-- The pushforward functor `Sheaf J A ⥤ Sheaf K A` associated to a functor `G : C ⥤ D` in the
 same direction as `G`. -/
 @[simps]
-def Sites.pushforward (G : C ⥤ D) : Sheaf J A ⥤ Sheaf K A :=
+def Functor.sheafPullback (G : C ⥤ D) : Sheaf J A ⥤ Sheaf K A :=
   sheafToPresheaf J A ⋙ lan G.op ⋙ presheafToSheaf K A
-#align category_theory.sites.pushforward CategoryTheory.Sites.pushforward
+#align category_theory.sites.pushforward CategoryTheory.Functor.sheafPullback
 -/
 
-instance (G : C ⥤ D) [RepresentablyFlat G] : PreservesFiniteLimits (Sites.pushforward A J K G) :=
+instance (G : C ⥤ D) [RepresentablyFlat G] :
+    PreservesFiniteLimits (Functor.sheafPullback A J K G) :=
   by
   apply (config := { instances := false }) comp_preserves_finite_limits
   · infer_instance
@@ -67,17 +68,18 @@ instance (G : C ⥤ D) [RepresentablyFlat G] : PreservesFiniteLimits (Sites.push
   · apply CategoryTheory.presheafToSheaf.Limits.preservesFiniteLimits.{u₁, v₁, v₁}
     infer_instance
 
-#print CategoryTheory.Sites.pullbackPushforwardAdjunction /-
+#print CategoryTheory.Functor.sheafAdjunctionContinuous /-
 /-- The pushforward functor is left adjoint to the pullback functor. -/
-def Sites.pullbackPushforwardAdjunction {G : C ⥤ D} (hG₁ : CompatiblePreserving K G)
-    (hG₂ : CoverPreserving J K G) : Sites.pushforward A J K G ⊣ Sites.pullback A hG₁ hG₂ :=
+def Functor.sheafAdjunctionContinuous {G : C ⥤ D} (hG₁ : CompatiblePreserving K G)
+    (hG₂ : CoverPreserving J K G) :
+    Functor.sheafPullback A J K G ⊣ Functor.sheafPushforwardContinuous A hG₁ hG₂ :=
   ((Lan.adjunction A G.op).comp (sheafificationAdjunction K A)).restrictFullyFaithful
     (sheafToPresheaf J A) (𝟭 _)
     (NatIso.ofComponents (fun _ => Iso.refl _) fun _ _ _ =>
       (Category.comp_id _).trans (Category.id_comp _).symm)
     (NatIso.ofComponents (fun _ => Iso.refl _) fun _ _ _ =>
       (Category.comp_id _).trans (Category.id_comp _).symm)
-#align category_theory.sites.pullback_pushforward_adjunction CategoryTheory.Sites.pullbackPushforwardAdjunction
+#align category_theory.sites.pullback_pushforward_adjunction CategoryTheory.Functor.sheafAdjunctionContinuous
 -/
 
 end CategoryTheory

bd15ff41

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) 2021 Andrew Yang. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Andrew Yang
 -/
-import Mathbin.CategoryTheory.Sites.CoverPreserving
-import Mathbin.CategoryTheory.Sites.LeftExact
+import CategoryTheory.Sites.CoverPreserving
+import CategoryTheory.Sites.LeftExact
 
 #align_import category_theory.sites.pushforward from "leanprover-community/mathlib"@"bd15ff41b70f5e2cc210f26f25a8d5c53b20d3de"

bd15ff41

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) 2021 Andrew Yang. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Andrew Yang
-
-! This file was ported from Lean 3 source module category_theory.sites.pushforward
-! leanprover-community/mathlib commit bd15ff41b70f5e2cc210f26f25a8d5c53b20d3de
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.CategoryTheory.Sites.CoverPreserving
 import Mathbin.CategoryTheory.Sites.LeftExact
 
+#align_import category_theory.sites.pushforward from "leanprover-community/mathlib"@"bd15ff41b70f5e2cc210f26f25a8d5c53b20d3de"
+
 /-!
 # Pushforward of sheaves

bd15ff41

bump to nightly-2023-05-13-02

mathlib commit https://github.com/leanprover-community/mathlib/commit/403190b5419b3f03f1a2893ad9352ca7f7d8bff6

d312d6d5

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Andrew Yang
 
 ! This file was ported from Lean 3 source module category_theory.sites.pushforward
-! leanprover-community/mathlib commit e2e38c005fc6f715502490da6cb0ec84df9ed228
+! leanprover-community/mathlib commit bd15ff41b70f5e2cc210f26f25a8d5c53b20d3de
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -14,6 +14,9 @@ import Mathbin.CategoryTheory.Sites.LeftExact
 /-!
 # Pushforward of sheaves
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 ## Main definitions
 
 * `category_theory.sites.pushforward`: the induced functor `Sheaf J A ⥤ Sheaf K A` for a

e2e38c00

bump to nightly-2023-05-11-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/28b2a92f2996d28e580450863c130955de0ed398

66e23fb2

Diff

@@ -49,12 +49,14 @@ attribute [local instance] reflects_limits_of_reflects_isomorphisms
 instance {X : C} : IsCofiltered (J.cover X) :=
   inferInstance
 
+#print CategoryTheory.Sites.pushforward /-
 /-- The pushforward functor `Sheaf J A ⥤ Sheaf K A` associated to a functor `G : C ⥤ D` in the
 same direction as `G`. -/
 @[simps]
 def Sites.pushforward (G : C ⥤ D) : Sheaf J A ⥤ Sheaf K A :=
   sheafToPresheaf J A ⋙ lan G.op ⋙ presheafToSheaf K A
 #align category_theory.sites.pushforward CategoryTheory.Sites.pushforward
+-/
 
 instance (G : C ⥤ D) [RepresentablyFlat G] : PreservesFiniteLimits (Sites.pushforward A J K G) :=
   by
@@ -65,6 +67,7 @@ instance (G : C ⥤ D) [RepresentablyFlat G] : PreservesFiniteLimits (Sites.push
   · apply CategoryTheory.presheafToSheaf.Limits.preservesFiniteLimits.{u₁, v₁, v₁}
     infer_instance
 
+#print CategoryTheory.Sites.pullbackPushforwardAdjunction /-
 /-- The pushforward functor is left adjoint to the pullback functor. -/
 def Sites.pullbackPushforwardAdjunction {G : C ⥤ D} (hG₁ : CompatiblePreserving K G)
     (hG₂ : CoverPreserving J K G) : Sites.pushforward A J K G ⊣ Sites.pullback A hG₁ hG₂ :=
@@ -75,6 +78,7 @@ def Sites.pullbackPushforwardAdjunction {G : C ⥤ D} (hG₁ : CompatiblePreserv
     (NatIso.ofComponents (fun _ => Iso.refl _) fun _ _ _ =>
       (Category.comp_id _).trans (Category.id_comp _).symm)
 #align category_theory.sites.pullback_pushforward_adjunction CategoryTheory.Sites.pullbackPushforwardAdjunction
+-/
 
 end CategoryTheory

e2e38c00

bump to nightly-2023-03-09-03

mathlib commit https://github.com/leanprover-community/mathlib/commit/21e3562c5e12d846c7def5eff8cdbc520d7d4936

061741a1

Changes in mathlib4

mathlib3

mathlib4

e2e38c00

chore(CategoryTheory/Adjunction): move Adjunction.restrictFullyFaithful to separate file (#12363)

Also resolves a TODO to add lemmas about Adjunction.restrictFullyFaithful

38faa1d2

Diff

@@ -3,6 +3,7 @@ Copyright (c) 2021 Andrew Yang. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Andrew Yang
 -/
+import Mathlib.CategoryTheory.Adjunction.Restrict
 import Mathlib.CategoryTheory.Sites.CoverPreserving
 import Mathlib.CategoryTheory.Sites.LeftExact

e2e38c00

chore(CategoryTheory): move Full, Faithful, EssSurj, IsEquivalence and ReflectsIsomorphisms to the Functor namespace (#11985)

These notions on functors are now Functor.Full, Functor.Faithful, Functor.EssSurj, Functor.IsEquivalence, Functor.ReflectsIsomorphisms. Deprecated aliases are introduced for the previous names.

65b7affc

Diff

@@ -44,7 +44,7 @@ instance [HasLimits A] : CreatesLimits (sheafToPresheaf J A) := inferInstance
 
 -- The assumptions so that we have sheafification
 variable [ConcreteCategory.{v₁} A] [PreservesLimits (forget A)] [HasColimits A] [HasLimits A]
-variable [PreservesFilteredColimits (forget A)] [ReflectsIsomorphisms (forget A)]
+variable [PreservesFilteredColimits (forget A)] [(forget A).ReflectsIsomorphisms]
 
 attribute [local instance] reflectsLimitsOfReflectsIsomorphisms

e2e38c00

chore(*): remove empty lines between variable statements (#11418)

Empty lines were removed by executing the following Python script twice

import os
import re


# Loop through each file in the repository
for dir_path, dirs, files in os.walk('.'):
  for filename in files:
    if filename.endswith('.lean'):
      file_path = os.path.join(dir_path, filename)

      # Open the file and read its contents
      with open(file_path, 'r') as file:
        content = file.read()

      # Use a regular expression to replace sequences of "variable" lines separated by empty lines
      # with sequences without empty lines
      modified_content = re.sub(r'(variable.*\n)\n(variable(?! .* in))', r'\1\2', content)

      # Write the modified content back to the file
      with open(file_path, 'w') as file:
        file.write(modified_content)

75c86f04

Diff

@@ -34,9 +34,7 @@ open CategoryTheory.Limits
 namespace CategoryTheory
 
 variable {C : Type v₁} [SmallCategory C] {D : Type v₁} [SmallCategory D] (G : C ⥤ D)
-
 variable (A : Type u₁) [Category.{v₁} A]
-
 variable (J : GrothendieckTopology C) (K : GrothendieckTopology D)
 
 -- Porting note: there was an explicit call to
@@ -46,7 +44,6 @@ instance [HasLimits A] : CreatesLimits (sheafToPresheaf J A) := inferInstance
 
 -- The assumptions so that we have sheafification
 variable [ConcreteCategory.{v₁} A] [PreservesLimits (forget A)] [HasColimits A] [HasLimits A]
-
 variable [PreservesFilteredColimits (forget A)] [ReflectsIsomorphisms (forget A)]
 
 attribute [local instance] reflectsLimitsOfReflectsIsomorphisms

e2e38c00

style: homogenise porting notes (#11145)

Homogenises porting notes via capitalisation and addition of whitespace.

It makes the following changes:

converts "--porting note" into "-- Porting note";
converts "porting note" into "Porting note".

8be0b69c

Diff

@@ -39,7 +39,7 @@ variable (A : Type u₁) [Category.{v₁} A]
 
 variable (J : GrothendieckTopology C) (K : GrothendieckTopology D)
 
--- porting note: there was an explicit call to
+-- Porting note: there was an explicit call to
 -- CategoryTheory.Sheaf.CategoryTheory.SheafToPresheaf.CategoryTheory.createsLimits.{u₁, v₁, v₁}
 -- but it is not necessary (it was not either in mathlib)
 instance [HasLimits A] : CreatesLimits (sheafToPresheaf J A) := inferInstance

e2e38c00

refactor(CategoryTheory/Sites): continuous functors (#8408)

This PR introduces the typeclass Functor.IsContinuous which says that the precomposition with a functor preserves the sheaf condition for Grothendieck topologies. It slightly refactors the previous main theorem about CoverPreserving and CompatiblePreserving functors: it now states that such functors are continuous. The pushforward functor for a continuous functor is defined under the Functor.IsContinuous assumption rather than the combination of both CoverPreserving and CompatiblePreserving. The property CoverLifting is renamed IsCocontinuous and it is made a class. The property IsCoverDense is also made a class.

Co-authored-by: Joël Riou <37772949+joelriou@users.noreply.github.com>

83613d27

Diff

@@ -9,12 +9,18 @@ import Mathlib.CategoryTheory.Sites.LeftExact
 #align_import category_theory.sites.pushforward from "leanprover-community/mathlib"@"e2e38c005fc6f715502490da6cb0ec84df9ed228"
 
 /-!
-# Pushforward of sheaves
+# Pullback of sheaves
 
 ## Main definitions
 
-* `CategoryTheory.Sites.Pushforward`: the induced functor `Sheaf J A ⥤ Sheaf K A` for a
-cover-preserving and compatible-preserving functor `G : (C, J) ⥤ (D, K)`.
+* `CategoryTheory.Functor.sheafPullback`: the functor `Sheaf J A ⥤ Sheaf K A` obtained
+as an extension of a functor `G : C ⥤ D` between the underlying categories.
+
+* `CategoryTheory.Functor.sheafAdjunctionContinuous`: the adjunction
+`G.sheafPullback A J K ⊣ G.sheafPushforwardContinuous A J K` when the functor
+`G` is continuous. In case `G` is representably flat, the pullback functor
+on sheaves commutes with finite limits: this is a morphism of sites in the
+sense of SGA 4 IV 4.9.
 
 -/
 
@@ -27,7 +33,7 @@ open CategoryTheory.Limits
 
 namespace CategoryTheory
 
-variable {C : Type v₁} [SmallCategory C] {D : Type v₁} [SmallCategory D]
+variable {C : Type v₁} [SmallCategory C] {D : Type v₁} [SmallCategory D] (G : C ⥤ D)
 
 variable (A : Type u₁) [Category.{v₁} A]
 
@@ -48,25 +54,23 @@ attribute [local instance] reflectsLimitsOfReflectsIsomorphisms
 instance {X : C} : IsCofiltered (J.Cover X) :=
   inferInstance
 
-/-- The pushforward functor `Sheaf J A ⥤ Sheaf K A` associated to a functor `G : C ⥤ D` in the
+/-- The pullback functor `Sheaf J A ⥤ Sheaf K A` associated to a functor `G : C ⥤ D` in the
 same direction as `G`. -/
 @[simps!]
-def Sites.pushforward (G : C ⥤ D) : Sheaf J A ⥤ Sheaf K A :=
+def Functor.sheafPullback : Sheaf J A ⥤ Sheaf K A :=
   sheafToPresheaf J A ⋙ lan G.op ⋙ presheafToSheaf K A
-#align category_theory.sites.pushforward CategoryTheory.Sites.pushforward
+#align category_theory.sites.pushforward CategoryTheory.Functor.sheafPullback
 
-instance (G : C ⥤ D) [RepresentablyFlat G] : PreservesFiniteLimits (Sites.pushforward A J K G) := by
+instance [RepresentablyFlat G] : PreservesFiniteLimits (G.sheafPullback A J K) := by
   have : PreservesFiniteLimits (lan (Functor.op G) ⋙ presheafToSheaf K A) :=
     compPreservesFiniteLimits _ _
   apply compPreservesFiniteLimits
 
-/-- The pushforward functor is left adjoint to the pullback functor. -/
-def Sites.pullbackPushforwardAdjunction {G : C ⥤ D} (hG₁ : CompatiblePreserving K G)
-    (hG₂ : CoverPreserving J K G) : Sites.pushforward A J K G ⊣ Sites.pullback A hG₁ hG₂ :=
+/-- The pullback functor is left adjoint to the pushforward functor. -/
+def Functor.sheafAdjunctionContinuous [Functor.IsContinuous.{v₁} G J K] :
+    G.sheafPullback A J K ⊣ G.sheafPushforwardContinuous A J K :=
   ((Lan.adjunction A G.op).comp (sheafificationAdjunction K A)).restrictFullyFaithful
-    (sheafToPresheaf J A) (𝟭 _)
-    (NatIso.ofComponents fun _ => Iso.refl _)
-    (NatIso.ofComponents fun _ => Iso.refl _)
-#align category_theory.sites.pullback_pushforward_adjunction CategoryTheory.Sites.pullbackPushforwardAdjunction
+    (sheafToPresheaf J A) (𝟭 _) (Iso.refl _) (Iso.refl _)
+#align category_theory.sites.pullback_pushforward_adjunction CategoryTheory.Functor.sheafAdjunctionContinuous
 
 end CategoryTheory

e2e38c00

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) 2021 Andrew Yang. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Andrew Yang
-
-! This file was ported from Lean 3 source module category_theory.sites.pushforward
-! leanprover-community/mathlib commit e2e38c005fc6f715502490da6cb0ec84df9ed228
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.CategoryTheory.Sites.CoverPreserving
 import Mathlib.CategoryTheory.Sites.LeftExact
 
+#align_import category_theory.sites.pushforward from "leanprover-community/mathlib"@"e2e38c005fc6f715502490da6cb0ec84df9ed228"
+
 /-!
 # Pushforward of sheaves

e2e38c00

chore: review of automation in category theory (#4793)

Clean up of automation in the category theory library. Leaving out unnecessary proof steps, or fields done by aesop_cat, and making more use of available autoparameters.

Co-authored-by: Scott Morrison <scott.morrison@anu.edu.au>

5b958613

Diff

@@ -68,10 +68,8 @@ def Sites.pullbackPushforwardAdjunction {G : C ⥤ D} (hG₁ : CompatiblePreserv
     (hG₂ : CoverPreserving J K G) : Sites.pushforward A J K G ⊣ Sites.pullback A hG₁ hG₂ :=
   ((Lan.adjunction A G.op).comp (sheafificationAdjunction K A)).restrictFullyFaithful
     (sheafToPresheaf J A) (𝟭 _)
-    (NatIso.ofComponents (fun _ => Iso.refl _) fun _ =>
-      (Category.comp_id _).trans (Category.id_comp _).symm)
-    (NatIso.ofComponents (fun _ => Iso.refl _) fun _ =>
-      (Category.comp_id _).trans (Category.id_comp _).symm)
+    (NatIso.ofComponents fun _ => Iso.refl _)
+    (NatIso.ofComponents fun _ => Iso.refl _)
 #align category_theory.sites.pullback_pushforward_adjunction CategoryTheory.Sites.pullbackPushforwardAdjunction
 
 end CategoryTheory

e2e38c00

feat: port CategoryTheory.Sites.Pushforward (#3899)

799bb95b

`category_theory.sites.pushforward` ⟷ `Mathlib.CategoryTheory.Sites.Pullback`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 3 + 342

category_theory.sites.pushforward ⟷ Mathlib.CategoryTheory.Sites.Pullback

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 3 + 342

`category_theory.sites.pushforward` ⟷ `Mathlib.CategoryTheory.Sites.Pullback`