category_theory.limits.constructions.pullbacks

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

cd7a8a18

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

f4758115

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) 2020 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel
 -/
-import Mathbin.CategoryTheory.Limits.Shapes.BinaryProducts
-import Mathbin.CategoryTheory.Limits.Shapes.Equalizers
-import Mathbin.CategoryTheory.Limits.Shapes.Pullbacks
+import CategoryTheory.Limits.Shapes.BinaryProducts
+import CategoryTheory.Limits.Shapes.Equalizers
+import CategoryTheory.Limits.Shapes.Pullbacks
 
 #align_import category_theory.limits.constructions.pullbacks from "leanprover-community/mathlib"@"f47581155c818e6361af4e4fda60d27d020c226b"

f4758115

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) 2020 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.constructions.pullbacks
-! leanprover-community/mathlib commit f47581155c818e6361af4e4fda60d27d020c226b
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.CategoryTheory.Limits.Shapes.BinaryProducts
 import Mathbin.CategoryTheory.Limits.Shapes.Equalizers
 import Mathbin.CategoryTheory.Limits.Shapes.Pullbacks
 
+#align_import category_theory.limits.constructions.pullbacks from "leanprover-community/mathlib"@"f47581155c818e6361af4e4fda60d27d020c226b"
+
 /-!
 # Constructing pullbacks from binary products and equalizers

f4758115

bump to nightly-2023-03-09-03

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

061741a1

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.constructions.pullbacks
-! leanprover-community/mathlib commit cd7a8a184d7c5635e30083eabc4baf5589c30b7a
+! leanprover-community/mathlib commit f47581155c818e6361af4e4fda60d27d020c226b
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -15,6 +15,9 @@ import Mathbin.CategoryTheory.Limits.Shapes.Pullbacks
 /-!
 # Constructing pullbacks from binary products and equalizers
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 If a category as binary products and equalizers, then it has pullbacks.
 Also, if a category has binary coproducts and coequalizers, then it has pushouts
 -/

cd7a8a18

bump to nightly-2023-03-07-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/3b267e70a936eebb21ab546f49a8df34dd300b25

a8442c3c

Diff

@@ -26,6 +26,7 @@ open CategoryTheory
 
 namespace CategoryTheory.Limits
 
+#print CategoryTheory.Limits.hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair /-
 /-- If the product `X ⨯ Y` and the equalizer of `π₁ ≫ f` and `π₂ ≫ g` exist, then the
     pullback of `f` and `g` exists: It is given by composing the equalizer with the projections. -/
 theorem hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair {C : Type u} [𝒞 : Category.{v} C]
@@ -49,11 +50,13 @@ theorem hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair {C : Type u} [
           · simpa using h₁
           · simpa using h₂ }
 #align category_theory.limits.has_limit_cospan_of_has_limit_pair_of_has_limit_parallel_pair CategoryTheory.Limits.hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair
+-/
 
 section
 
 attribute [local instance] has_limit_cospan_of_has_limit_pair_of_has_limit_parallel_pair
 
+#print CategoryTheory.Limits.hasPullbacks_of_hasBinaryProducts_of_hasEqualizers /-
 /-- If a category has all binary products and all equalizers, then it also has all pullbacks.
     As usual, this is not an instance, since there may be a more direct way to construct
     pullbacks. -/
@@ -61,9 +64,11 @@ theorem hasPullbacks_of_hasBinaryProducts_of_hasEqualizers (C : Type u) [𝒞 :
     [HasBinaryProducts C] [HasEqualizers C] : HasPullbacks C :=
   { HasLimit := fun F => hasLimitOfIso (diagramIsoCospan F).symm }
 #align category_theory.limits.has_pullbacks_of_has_binary_products_of_has_equalizers CategoryTheory.Limits.hasPullbacks_of_hasBinaryProducts_of_hasEqualizers
+-/
 
 end
 
+#print CategoryTheory.Limits.hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair /-
 /-- If the coproduct `Y ⨿ Z` and the coequalizer of `f ≫ ι₁` and `g ≫ ι₂` exist, then the
     pushout of `f` and `g` exists: It is given by composing the inclusions with the coequalizer. -/
 theorem hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair {C : Type u}
@@ -88,11 +93,13 @@ theorem hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair {C : Type
           · simpa using h₁
           · simpa using h₂ }
 #align category_theory.limits.has_colimit_span_of_has_colimit_pair_of_has_colimit_parallel_pair CategoryTheory.Limits.hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair
+-/
 
 section
 
 attribute [local instance] has_colimit_span_of_has_colimit_pair_of_has_colimit_parallel_pair
 
+#print CategoryTheory.Limits.hasPushouts_of_hasBinaryCoproducts_of_hasCoequalizers /-
 /-- If a category has all binary coproducts and all coequalizers, then it also has all pushouts.
     As usual, this is not an instance, since there may be a more direct way to construct
     pushouts. -/
@@ -100,6 +107,7 @@ theorem hasPushouts_of_hasBinaryCoproducts_of_hasCoequalizers (C : Type u) [𝒞
     [HasBinaryCoproducts C] [HasCoequalizers C] : HasPushouts C :=
   hasPushouts_of_hasColimit_span C
 #align category_theory.limits.has_pushouts_of_has_binary_coproducts_of_has_coequalizers CategoryTheory.Limits.hasPushouts_of_hasBinaryCoproducts_of_hasCoequalizers
+-/
 
 end

cd7a8a18

bump to nightly-2023-02-28-22

mathlib commit https://github.com/leanprover-community/mathlib/commit/9da1b3534b65d9661eb8f42443598a92bbb49211

1fb1623f

Diff

@@ -59,7 +59,7 @@ attribute [local instance] has_limit_cospan_of_has_limit_pair_of_has_limit_paral
     pullbacks. -/
 theorem hasPullbacks_of_hasBinaryProducts_of_hasEqualizers (C : Type u) [𝒞 : Category.{v} C]
     [HasBinaryProducts C] [HasEqualizers C] : HasPullbacks C :=
-  { HasLimit := fun F => hasLimit_of_iso (diagramIsoCospan F).symm }
+  { HasLimit := fun F => hasLimitOfIso (diagramIsoCospan F).symm }
 #align category_theory.limits.has_pullbacks_of_has_binary_products_of_has_equalizers CategoryTheory.Limits.hasPullbacks_of_hasBinaryProducts_of_hasEqualizers
 
 end

cd7a8a18

bump to nightly-2023-02-27-08

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

91d8c210

Diff

@@ -28,7 +28,7 @@ namespace CategoryTheory.Limits
 
 /-- If the product `X ⨯ Y` and the equalizer of `π₁ ≫ f` and `π₂ ≫ g` exist, then the
     pullback of `f` and `g` exists: It is given by composing the equalizer with the projections. -/
-theorem hasLimitCospanOfHasLimitPairOfHasLimitParallelPair {C : Type u} [𝒞 : Category.{v} C]
+theorem hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair {C : Type u} [𝒞 : Category.{v} C]
     {X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z) [HasLimit (pair X Y)]
     [HasLimit (parallelPair (prod.fst ≫ f) (prod.snd ≫ g))] : HasLimit (cospan f g) :=
   let π₁ : X ⨯ Y ⟶ X := prod.fst
@@ -48,7 +48,7 @@ theorem hasLimitCospanOfHasLimitPairOfHasLimitParallelPair {C : Type u} [𝒞 :
           ext
           · simpa using h₁
           · simpa using h₂ }
-#align category_theory.limits.has_limit_cospan_of_has_limit_pair_of_has_limit_parallel_pair CategoryTheory.Limits.hasLimitCospanOfHasLimitPairOfHasLimitParallelPair
+#align category_theory.limits.has_limit_cospan_of_has_limit_pair_of_has_limit_parallel_pair CategoryTheory.Limits.hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair
 
 section
 
@@ -59,15 +59,15 @@ attribute [local instance] has_limit_cospan_of_has_limit_pair_of_has_limit_paral
     pullbacks. -/
 theorem hasPullbacks_of_hasBinaryProducts_of_hasEqualizers (C : Type u) [𝒞 : Category.{v} C]
     [HasBinaryProducts C] [HasEqualizers C] : HasPullbacks C :=
-  { HasLimit := fun F => hasLimitOfIso (diagramIsoCospan F).symm }
+  { HasLimit := fun F => hasLimit_of_iso (diagramIsoCospan F).symm }
 #align category_theory.limits.has_pullbacks_of_has_binary_products_of_has_equalizers CategoryTheory.Limits.hasPullbacks_of_hasBinaryProducts_of_hasEqualizers
 
 end
 
 /-- If the coproduct `Y ⨿ Z` and the coequalizer of `f ≫ ι₁` and `g ≫ ι₂` exist, then the
     pushout of `f` and `g` exists: It is given by composing the inclusions with the coequalizer. -/
-theorem hasColimitSpanOfHasColimitPairOfHasColimitParallelPair {C : Type u} [𝒞 : Category.{v} C]
-    {X Y Z : C} (f : X ⟶ Y) (g : X ⟶ Z) [HasColimit (pair Y Z)]
+theorem hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair {C : Type u}
+    [𝒞 : Category.{v} C] {X Y Z : C} (f : X ⟶ Y) (g : X ⟶ Z) [HasColimit (pair Y Z)]
     [HasColimit (parallelPair (f ≫ coprod.inl) (g ≫ coprod.inr))] : HasColimit (span f g) :=
   let ι₁ : Y ⟶ Y ⨿ Z := coprod.inl
   let ι₂ : Z ⟶ Y ⨿ Z := coprod.inr
@@ -87,7 +87,7 @@ theorem hasColimitSpanOfHasColimitPairOfHasColimitParallelPair {C : Type u} [
           ext
           · simpa using h₁
           · simpa using h₂ }
-#align category_theory.limits.has_colimit_span_of_has_colimit_pair_of_has_colimit_parallel_pair CategoryTheory.Limits.hasColimitSpanOfHasColimitPairOfHasColimitParallelPair
+#align category_theory.limits.has_colimit_span_of_has_colimit_pair_of_has_colimit_parallel_pair CategoryTheory.Limits.hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair
 
 section

cd7a8a18

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

cd7a8a18

chore: prepare Lean version bump with explicit simp (#10999)

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

38bce757

Diff

@@ -39,7 +39,7 @@ theorem hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair {C : Type u} [
           (prod.lift (s.π.app WalkingCospan.left) (s.π.app WalkingCospan.right)) <| by
               rw [← Category.assoc, limit.lift_π, ← Category.assoc, limit.lift_π];
                 exact PullbackCone.condition _)
-          (by simp) (by simp) fun s m h₁ h₂ => by
+          (by simp [π₁, e]) (by simp [π₂, e]) fun s m h₁ h₂ => by
           ext
           · dsimp; simpa using h₁
           · simpa using h₂ }
@@ -77,7 +77,7 @@ theorem hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair {C : Type
               (coprod.desc (s.ι.app WalkingSpan.left) (s.ι.app WalkingSpan.right)) <| by
             rw [Category.assoc, colimit.ι_desc, Category.assoc, colimit.ι_desc]
             exact PushoutCocone.condition _)
-          (by simp) (by simp) fun s m h₁ h₂ => by
+          (by simp [ι₁, c]) (by simp [ι₂, c]) fun s m h₁ h₂ => by
           ext
           · simpa using h₁
           · simpa using h₂ }

cd7a8a18

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) 2020 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.constructions.pullbacks
-! leanprover-community/mathlib commit cd7a8a184d7c5635e30083eabc4baf5589c30b7a
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.CategoryTheory.Limits.Shapes.BinaryProducts
 import Mathlib.CategoryTheory.Limits.Shapes.Equalizers
 import Mathlib.CategoryTheory.Limits.Shapes.Pullbacks
 
+#align_import category_theory.limits.constructions.pullbacks from "leanprover-community/mathlib"@"cd7a8a184d7c5635e30083eabc4baf5589c30b7a"
+
 /-!
 # Constructing pullbacks from binary products and equalizers

cd7a8a18

feat: more consistent use of ext, and updating porting notes. (#5242)

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

dbae2f17

Diff

@@ -43,8 +43,7 @@ theorem hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair {C : Type u} [
               rw [← Category.assoc, limit.lift_π, ← Category.assoc, limit.lift_π];
                 exact PullbackCone.condition _)
           (by simp) (by simp) fun s m h₁ h₂ => by
-          apply equalizer.hom_ext
-          apply prod.hom_ext
+          ext
           · dsimp; simpa using h₁
           · simpa using h₂ }
 #align category_theory.limits.has_limit_cospan_of_has_limit_pair_of_has_limit_parallel_pair CategoryTheory.Limits.hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair
@@ -82,8 +81,7 @@ theorem hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair {C : Type
             rw [Category.assoc, colimit.ι_desc, Category.assoc, colimit.ι_desc]
             exact PushoutCocone.condition _)
           (by simp) (by simp) fun s m h₁ h₂ => by
-          apply coequalizer.hom_ext
-          apply coprod.hom_ext
+          ext
           · simpa using h₁
           · simpa using h₂ }
 #align category_theory.limits.has_colimit_span_of_has_colimit_pair_of_has_colimit_parallel_pair CategoryTheory.Limits.hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair

cd7a8a18

chore: bye-bye, solo bys! (#3825)

This PR puts, with one exception, every single remaining by that lies all by itself on its own line to the previous line, thus matching the current behaviour of start-port.sh. The exception is when the by begins the second or later argument to a tuple or anonymous constructor; see https://github.com/leanprover-community/mathlib4/pull/3825#discussion_r1186702599.

Essentially this is s/\n *by$/ by/g, but with manual editing to satisfy the linter's max-100-char-line requirement. The Python style linter is also modified to catch these "isolated bys".

14167e48

Diff

@@ -77,11 +77,10 @@ theorem hasColimit_span_of_hasColimit_pair_of_hasColimit_parallelPair {C : Type
           rw [← Category.assoc, ← Category.assoc, coequalizer.condition]
       isColimit :=
         PushoutCocone.IsColimit.mk _
-          (fun s =>
-            coequalizer.desc (coprod.desc (s.ι.app WalkingSpan.left) (s.ι.app WalkingSpan.right)) <|
-              by
-              rw [Category.assoc, colimit.ι_desc, Category.assoc, colimit.ι_desc];
-                exact PushoutCocone.condition _)
+          (fun s => coequalizer.desc
+              (coprod.desc (s.ι.app WalkingSpan.left) (s.ι.app WalkingSpan.right)) <| by
+            rw [Category.assoc, colimit.ι_desc, Category.assoc, colimit.ι_desc]
+            exact PushoutCocone.condition _)
           (by simp) (by simp) fun s m h₁ h₂ => by
           apply coequalizer.hom_ext
           apply coprod.hom_ext

cd7a8a18

chore: strip trailing spaces in lean files (#2828)

vscode is already configured by .vscode/settings.json to trim these on save. It's not clear how they've managed to stick around.

By doing this all in one PR now, it avoids getting random whitespace diffs in PRs later.

This was done with a regex search in vscode,

6ceb5945

Diff

@@ -38,12 +38,12 @@ theorem hasLimit_cospan_of_hasLimit_pair_of_hasLimit_parallelPair {C : Type u} [
     { cone :=
         PullbackCone.mk (e ≫ π₁) (e ≫ π₂) <| by rw [Category.assoc, equalizer.condition]; simp
       isLimit :=
-        PullbackCone.IsLimit.mk _ (fun s => equalizer.lift 
+        PullbackCone.IsLimit.mk _ (fun s => equalizer.lift
           (prod.lift (s.π.app WalkingCospan.left) (s.π.app WalkingCospan.right)) <| by
               rw [← Category.assoc, limit.lift_π, ← Category.assoc, limit.lift_π];
                 exact PullbackCone.condition _)
           (by simp) (by simp) fun s m h₁ h₂ => by
-          apply equalizer.hom_ext 
+          apply equalizer.hom_ext
           apply prod.hom_ext
           · dsimp; simpa using h₁
           · simpa using h₂ }
@@ -104,4 +104,3 @@ theorem hasPushouts_of_hasBinaryCoproducts_of_hasCoequalizers (C : Type u) [Cate
 end
 
 end CategoryTheory.Limits
-

cd7a8a18

feat: port CategoryTheory.Limits.Constructions.Pullbacks (#2658)

6ce32ee4

`category_theory.limits.constructions.pullbacks` ⟷ `Mathlib.CategoryTheory.Limits.Constructions.Pullbacks`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 111

category_theory.limits.constructions.pullbacks ⟷ Mathlib.CategoryTheory.Limits.Constructions.Pullbacks

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 111

`category_theory.limits.constructions.pullbacks` ⟷ `Mathlib.CategoryTheory.Limits.Constructions.Pullbacks`