category_theory.abelian.basic ⟷ Mathlib.CategoryTheory.Abelian.Basic

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

@@ -217,7 +217,7 @@ def normalMonoCategory : NormalMonoCategory C
         have aux : _ := _
         refine' is_limit_aux _ (fun A => limit.lift _ _ ≫ inv (image_mono_factorisation f).e) aux _
         · intro A g hg
-          rw [kernel_fork.ι_of_ι] at hg 
+          rw [kernel_fork.ι_of_ι] at hg
           rw [← cancel_mono f, hg, ← aux, kernel_fork.ι_of_ι]
         · intro A
           simp only [kernel_fork.ι_of_ι, category.assoc]
@@ -248,7 +248,7 @@ def normalEpiCategory : NormalEpiCategory C
                 inv (abelian.coimage_image_comparison f) ≫ colimit.desc _ _)
             aux _
         · intro A g hg
-          rw [cokernel_cofork.π_of_π] at hg 
+          rw [cokernel_cofork.π_of_π] at hg
           rw [← cancel_epi f, hg, ← aux, cokernel_cofork.π_of_π]
         · intro A
           simp only [cokernel_cofork.π_of_π, ← category.assoc]
@@ -729,8 +729,8 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
         (pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct f g)
     -- We use this fact to obtain a factorization of u through (f, -g) via some d : Z ⟶ R.
     obtain ⟨d, hd⟩ := cokernel_cofork.is_colimit.desc' this u hu
-    change Z ⟶ R at d 
-    change biprod.desc f (-g) ≫ d = u at hd 
+    change Z ⟶ R at d
+    change biprod.desc f (-g) ≫ d = u at hd
     -- But then f ≫ d = 0:
     have : f ≫ d = 0;
     calc
@@ -768,8 +768,8 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
         (pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct f g)
     -- We use this fact to obtain a factorization of u through (f, -g) via some d : Z ⟶ R.
     obtain ⟨d, hd⟩ := cokernel_cofork.is_colimit.desc' this u hu
-    change Z ⟶ R at d 
-    change biprod.desc f (-g) ≫ d = u at hd 
+    change Z ⟶ R at d
+    change biprod.desc f (-g) ≫ d = u at hd
     -- But then (-g) ≫ d = 0:
     have : (-g) ≫ d = 0;
     calc
@@ -833,8 +833,8 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       mono_is_kernel_of_cokernel _
         (biproduct_to_pushout_is_cokernel.is_colimit_biproduct_to_pushout f g)
     obtain ⟨d, hd⟩ := kernel_fork.is_limit.lift' this u hu
-    change R ⟶ X at d 
-    change d ≫ biprod.lift f (-g) = u at hd 
+    change R ⟶ X at d
+    change d ≫ biprod.lift f (-g) = u at hd
     have : d ≫ f = 0;
     calc
       d ≫ f = d ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [biprod.lift_fst]
@@ -860,8 +860,8 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
       mono_is_kernel_of_cokernel _
         (biproduct_to_pushout_is_cokernel.is_colimit_biproduct_to_pushout f g)
     obtain ⟨d, hd⟩ := kernel_fork.is_limit.lift' this u hu
-    change R ⟶ X at d 
-    change d ≫ biprod.lift f (-g) = u at hd 
+    change R ⟶ X at d
+    change d ≫ biprod.lift f (-g) = u at hd
     have : d ≫ (-g) = 0;
     calc
       d ≫ (-g) = d ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [biprod.lift_snd]

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

@@ -3,11 +3,11 @@ Copyright (c) 2020 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel, Johan Commelin, Scott Morrison
 -/
-import Mathbin.CategoryTheory.Limits.Constructions.Pullbacks
-import Mathbin.CategoryTheory.Preadditive.Biproducts
-import Mathbin.CategoryTheory.Limits.Shapes.Images
-import Mathbin.CategoryTheory.Limits.Constructions.LimitsOfProductsAndEqualizers
-import Mathbin.CategoryTheory.Abelian.NonPreadditive
+import CategoryTheory.Limits.Constructions.Pullbacks
+import CategoryTheory.Preadditive.Biproducts
+import CategoryTheory.Limits.Shapes.Images
+import CategoryTheory.Limits.Constructions.LimitsOfProductsAndEqualizers
+import CategoryTheory.Abelian.NonPreadditive
 
 #align_import category_theory.abelian.basic from "leanprover-community/mathlib"@"a5ff45a1c92c278b03b52459a620cfd9c49ebc80"
 

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

@@ -2,11 +2,6 @@
 Copyright (c) 2020 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel, Johan Commelin, Scott Morrison
-
-! This file was ported from Lean 3 source module category_theory.abelian.basic
-! leanprover-community/mathlib commit a5ff45a1c92c278b03b52459a620cfd9c49ebc80
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.CategoryTheory.Limits.Constructions.Pullbacks
 import Mathbin.CategoryTheory.Preadditive.Biproducts
@@ -14,6 +9,8 @@ import Mathbin.CategoryTheory.Limits.Shapes.Images
 import Mathbin.CategoryTheory.Limits.Constructions.LimitsOfProductsAndEqualizers
 import Mathbin.CategoryTheory.Abelian.NonPreadditive
 
+#align_import category_theory.abelian.basic from "leanprover-community/mathlib"@"a5ff45a1c92c278b03b52459a620cfd9c49ebc80"
+
 /-!
 # Abelian categories
 

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

@@ -523,6 +523,7 @@ variable {X Y : C} {f : X ⟶ Y}
 
 attribute [local instance] non_preadditive_abelian
 
+#print CategoryTheory.Abelian.epiIsCokernelOfKernel /-
 /-- In an abelian category, an epi is the cokernel of its kernel. More precisely:
     If `f` is an epimorphism and `s` is some limit kernel cone on `f`, then `f` is a cokernel
     of `fork.ι s`. -/
@@ -530,7 +531,9 @@ def epiIsCokernelOfKernel [Epi f] (s : Fork f 0) (h : IsLimit s) :
     IsColimit (CokernelCofork.ofπ f (KernelFork.condition s)) :=
   NonPreadditiveAbelian.epiIsCokernelOfKernel s h
 #align category_theory.abelian.epi_is_cokernel_of_kernel CategoryTheory.Abelian.epiIsCokernelOfKernel
+-/
 
+#print CategoryTheory.Abelian.monoIsKernelOfCokernel /-
 /-- In an abelian category, a mono is the kernel of its cokernel. More precisely:
     If `f` is a monomorphism and `s` is some colimit cokernel cocone on `f`, then `f` is a kernel
     of `cofork.π s`. -/
@@ -538,6 +541,7 @@ def monoIsKernelOfCokernel [Mono f] (s : Cofork f 0) (h : IsColimit s) :
     IsLimit (KernelFork.ofι f (CokernelCofork.condition s)) :=
   NonPreadditiveAbelian.monoIsKernelOfCokernel s h
 #align category_theory.abelian.mono_is_kernel_of_cokernel CategoryTheory.Abelian.monoIsKernelOfCokernel
+-/
 
 variable (f)
 
@@ -637,6 +641,7 @@ abbrev pullbackToBiproduct : pullback f g ⟶ X ⊞ Y :=
 #align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproduct
 -/
 
+#print CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductFork /-
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` induces a kernel cone on the map
     `biproduct X Y ⟶ Z` induced by `f` and `g`. A slightly more intuitive way to think of
     this may be that it induces an equalizer fork on the maps induced by `(f, 0)` and
@@ -645,7 +650,9 @@ abbrev pullbackToBiproductFork : KernelFork (biprod.desc f (-g)) :=
   KernelFork.ofι (pullbackToBiproduct f g) <| by
     rw [biprod.lift_desc, comp_neg, pullback.condition, add_right_neg]
 #align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct_fork CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductFork
+-/
 
+#print CategoryTheory.Abelian.PullbackToBiproductIsKernel.isLimitPullbackToBiproduct /-
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` is a kernel of the map induced by
     `(f, -g)`. -/
 def isLimitPullbackToBiproduct : IsLimit (pullbackToBiproductFork f g) :=
@@ -661,6 +668,7 @@ def isLimitPullbackToBiproduct : IsLimit (pullbackToBiproductFork f g) :=
       · rw [biprod.lift_snd, pullback.lift_snd])
     fun s m h => by ext <;> simp [← h]
 #align category_theory.abelian.pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct CategoryTheory.Abelian.PullbackToBiproductIsKernel.isLimitPullbackToBiproduct
+-/
 
 end PullbackToBiproductIsKernel
 
@@ -675,13 +683,16 @@ abbrev biproductToPushout : Y ⊞ Z ⟶ pushout f g :=
 #align category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushout
 -/
 
+#print CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushoutCofork /-
 /-- The canonical map `Y ⊞ Z ⟶ pushout f g` induces a cokernel cofork on the map
     `X ⟶ Y ⊞ Z` induced by `f` and `-g`. -/
 abbrev biproductToPushoutCofork : CokernelCofork (biprod.lift f (-g)) :=
   CokernelCofork.ofπ (biproductToPushout f g) <| by
     rw [biprod.lift_desc, neg_comp, pushout.condition, add_right_neg]
 #align category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout_cofork CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushoutCofork
+-/
 
+#print CategoryTheory.Abelian.BiproductToPushoutIsCokernel.isColimitBiproductToPushout /-
 /-- The cofork induced by the canonical map `Y ⊞ Z ⟶ pushout f g` is in fact a colimit cokernel
     cofork. -/
 def isColimitBiproductToPushout : IsColimit (biproductToPushoutCofork f g) :=
@@ -693,6 +704,7 @@ def isColimitBiproductToPushout : IsColimit (biproductToPushoutCofork f g) :=
             biprod.lift_eq, cofork.condition s, zero_comp])
     (fun s => by ext <;> simp) fun s m h => by ext <;> simp [← h]
 #align category_theory.abelian.biproduct_to_pushout_is_cokernel.is_colimit_biproduct_to_pushout CategoryTheory.Abelian.BiproductToPushoutIsCokernel.isColimitBiproductToPushout
+-/
 
 end BiproductToPushoutIsCokernel
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/7e5137f579de09a059a5ce98f364a04e221aabf0

@@ -728,7 +728,6 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
       f ≫ d = (biprod.inl ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inl_desc]
       _ = biprod.inl ≫ u := by rw [category.assoc, hd]
       _ = 0 := biprod.inl_desc _ _
-      
     -- But f is an epimorphism, so d = 0...
     have : d = 0 := (cancel_epi f).1 (by simpa)
     -- ...or, in other words, e = 0.
@@ -738,7 +737,6 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
       _ = biprod.inr ≫ biprod.desc f (-g) ≫ 0 := by rw [this]
       _ = (biprod.inr ≫ biprod.desc f (-g)) ≫ 0 := by rw [← category.assoc]
       _ = 0 := has_zero_morphisms.comp_zero _ _
-      
 #align category_theory.abelian.epi_pullback_of_epi_f CategoryTheory.Abelian.epi_pullback_of_epi_f
 -/
 
@@ -769,7 +767,6 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
       (-g) ≫ d = (biprod.inr ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inr_desc]
       _ = biprod.inr ≫ u := by rw [category.assoc, hd]
       _ = 0 := biprod.inr_desc _ _
-      
     -- But g is an epimorphism, thus so is -g, so d = 0...
     have : d = 0 := (cancel_epi (-g)).1 (by simpa)
     -- ...or, in other words, e = 0.
@@ -779,7 +776,6 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
       _ = biprod.inl ≫ biprod.desc f (-g) ≫ 0 := by rw [this]
       _ = (biprod.inl ≫ biprod.desc f (-g)) ≫ 0 := by rw [← category.assoc]
       _ = 0 := has_zero_morphisms.comp_zero _ _
-      
 #align category_theory.abelian.epi_pullback_of_epi_g CategoryTheory.Abelian.epi_pullback_of_epi_g
 -/
 
@@ -835,7 +831,6 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       d ≫ f = d ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [biprod.lift_fst]
       _ = u ≫ biprod.fst := by rw [← category.assoc, hd]
       _ = 0 := biprod.lift_fst _ _
-      
     have : d = 0 := (cancel_mono f).1 (by simpa)
     calc
       e = u ≫ biprod.snd := by rw [biprod.lift_snd]
@@ -843,7 +838,6 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       _ = (0 ≫ biprod.lift f (-g)) ≫ biprod.snd := by rw [this]
       _ = 0 ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [category.assoc]
       _ = 0 := zero_comp
-      
 #align category_theory.abelian.mono_pushout_of_mono_f CategoryTheory.Abelian.mono_pushout_of_mono_f
 -/
 
@@ -864,7 +858,6 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
       d ≫ (-g) = d ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [biprod.lift_snd]
       _ = u ≫ biprod.snd := by rw [← category.assoc, hd]
       _ = 0 := biprod.lift_snd _ _
-      
     have : d = 0 := (cancel_mono (-g)).1 (by simpa)
     calc
       e = u ≫ biprod.fst := by rw [biprod.lift_fst]
@@ -872,7 +865,6 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
       _ = (0 ≫ biprod.lift f (-g)) ≫ biprod.fst := by rw [this]
       _ = 0 ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [category.assoc]
       _ = 0 := zero_comp
-      
 #align category_theory.abelian.mono_pushout_of_mono_g CategoryTheory.Abelian.mono_pushout_of_mono_g
 -/
 

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

@@ -444,7 +444,8 @@ See `category_theory.abelian.of_coimage_image_comparison_is_iso` for the convers
 -/
 instance : IsIso (coimageImageComparison f) :=
   by
-  convert is_iso.of_iso
+  convert
+    is_iso.of_iso
       (is_image.iso_ext (coimage_strong_epi_mono_factorisation f).toMonoIsImage
         (image_strong_epi_mono_factorisation f).toMonoIsImage)
   ext
@@ -878,8 +879,8 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
 #print CategoryTheory.Abelian.mono_inr_of_isColimit /-
 theorem mono_inr_of_isColimit [Mono f] {s : PushoutCocone f g} (hs : IsColimit s) : Mono s.inr :=
   by
-  convert mono_of_mono_fac
-      (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
+  convert
+    mono_of_mono_fac (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
   · rfl
   · exact abelian.mono_pushout_of_mono_f _ _
 #align category_theory.abelian.mono_inr_of_is_colimit CategoryTheory.Abelian.mono_inr_of_isColimit
@@ -888,8 +889,8 @@ theorem mono_inr_of_isColimit [Mono f] {s : PushoutCocone f g} (hs : IsColimit s
 #print CategoryTheory.Abelian.mono_inl_of_isColimit /-
 theorem mono_inl_of_isColimit [Mono g] {s : PushoutCocone f g} (hs : IsColimit s) : Mono s.inl :=
   by
-  convert mono_of_mono_fac
-      (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
+  convert
+    mono_of_mono_fac (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
   · rfl
   · exact abelian.mono_pushout_of_mono_g _ _
 #align category_theory.abelian.mono_inl_of_is_colimit CategoryTheory.Abelian.mono_inl_of_isColimit
@@ -927,8 +928,8 @@ def abelian : Abelian C :=
        the goal it creates for the two instances of `has_zero_morphisms`, and the proof is complete. -/
     NonPreadditiveAbelian.preadditive with
     HasFiniteProducts := by infer_instance
-    HasKernels := by convert(by infer_instance : limits.has_kernels C)
-    HasCokernels := by convert(by infer_instance : limits.has_cokernels C)
+    HasKernels := by convert (by infer_instance : limits.has_kernels C)
+    HasCokernels := by convert (by infer_instance : limits.has_cokernels C)
     normalMonoOfMono := by intros; convert normal_mono_of_mono f
     normalEpiOfEpi := by intros; convert normal_epi_of_epi f }
 #align category_theory.non_preadditive_abelian.abelian CategoryTheory.NonPreadditiveAbelian.abelian

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

@@ -220,7 +220,7 @@ def normalMonoCategory : NormalMonoCategory C
         have aux : _ := _
         refine' is_limit_aux _ (fun A => limit.lift _ _ ≫ inv (image_mono_factorisation f).e) aux _
         · intro A g hg
-          rw [kernel_fork.ι_of_ι] at hg
+          rw [kernel_fork.ι_of_ι] at hg 
           rw [← cancel_mono f, hg, ← aux, kernel_fork.ι_of_ι]
         · intro A
           simp only [kernel_fork.ι_of_ι, category.assoc]
@@ -251,7 +251,7 @@ def normalEpiCategory : NormalEpiCategory C
                 inv (abelian.coimage_image_comparison f) ≫ colimit.desc _ _)
             aux _
         · intro A g hg
-          rw [cokernel_cofork.π_of_π] at hg
+          rw [cokernel_cofork.π_of_π] at hg 
           rw [← cancel_epi f, hg, ← aux, cokernel_cofork.π_of_π]
         · intro A
           simp only [cokernel_cofork.π_of_π, ← category.assoc]
@@ -719,8 +719,8 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
         (pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct f g)
     -- We use this fact to obtain a factorization of u through (f, -g) via some d : Z ⟶ R.
     obtain ⟨d, hd⟩ := cokernel_cofork.is_colimit.desc' this u hu
-    change Z ⟶ R at d
-    change biprod.desc f (-g) ≫ d = u at hd
+    change Z ⟶ R at d 
+    change biprod.desc f (-g) ≫ d = u at hd 
     -- But then f ≫ d = 0:
     have : f ≫ d = 0;
     calc
@@ -760,8 +760,8 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
         (pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct f g)
     -- We use this fact to obtain a factorization of u through (f, -g) via some d : Z ⟶ R.
     obtain ⟨d, hd⟩ := cokernel_cofork.is_colimit.desc' this u hu
-    change Z ⟶ R at d
-    change biprod.desc f (-g) ≫ d = u at hd
+    change Z ⟶ R at d 
+    change biprod.desc f (-g) ≫ d = u at hd 
     -- But then (-g) ≫ d = 0:
     have : (-g) ≫ d = 0;
     calc
@@ -827,8 +827,8 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       mono_is_kernel_of_cokernel _
         (biproduct_to_pushout_is_cokernel.is_colimit_biproduct_to_pushout f g)
     obtain ⟨d, hd⟩ := kernel_fork.is_limit.lift' this u hu
-    change R ⟶ X at d
-    change d ≫ biprod.lift f (-g) = u at hd
+    change R ⟶ X at d 
+    change d ≫ biprod.lift f (-g) = u at hd 
     have : d ≫ f = 0;
     calc
       d ≫ f = d ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [biprod.lift_fst]
@@ -856,8 +856,8 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
       mono_is_kernel_of_cokernel _
         (biproduct_to_pushout_is_cokernel.is_colimit_biproduct_to_pushout f g)
     obtain ⟨d, hd⟩ := kernel_fork.is_limit.lift' this u hu
-    change R ⟶ X at d
-    change d ≫ biprod.lift f (-g) = u at hd
+    change R ⟶ X at d 
+    change d ≫ biprod.lift f (-g) = u at hd 
     have : d ≫ (-g) = 0;
     calc
       d ≫ (-g) = d ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [biprod.lift_snd]
@@ -929,8 +929,8 @@ def abelian : Abelian C :=
     HasFiniteProducts := by infer_instance
     HasKernels := by convert(by infer_instance : limits.has_kernels C)
     HasCokernels := by convert(by infer_instance : limits.has_cokernels C)
-    normalMonoOfMono := by intros ; convert normal_mono_of_mono f
-    normalEpiOfEpi := by intros ; convert normal_epi_of_epi f }
+    normalMonoOfMono := by intros; convert normal_mono_of_mono f
+    normalEpiOfEpi := by intros; convert normal_epi_of_epi f }
 #align category_theory.non_preadditive_abelian.abelian CategoryTheory.NonPreadditiveAbelian.abelian
 -/
 

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

@@ -522,9 +522,6 @@ variable {X Y : C} {f : X ⟶ Y}
 
 attribute [local instance] non_preadditive_abelian
 
-/- warning: category_theory.abelian.epi_is_cokernel_of_kernel -> CategoryTheory.Abelian.epiIsCokernelOfKernel is a dubious translation:
-<too large>
-Case conversion may be inaccurate. Consider using '#align category_theory.abelian.epi_is_cokernel_of_kernel CategoryTheory.Abelian.epiIsCokernelOfKernelₓ'. -/
 /-- In an abelian category, an epi is the cokernel of its kernel. More precisely:
     If `f` is an epimorphism and `s` is some limit kernel cone on `f`, then `f` is a cokernel
     of `fork.ι s`. -/
@@ -533,9 +530,6 @@ def epiIsCokernelOfKernel [Epi f] (s : Fork f 0) (h : IsLimit s) :
   NonPreadditiveAbelian.epiIsCokernelOfKernel s h
 #align category_theory.abelian.epi_is_cokernel_of_kernel CategoryTheory.Abelian.epiIsCokernelOfKernel
 
-/- warning: category_theory.abelian.mono_is_kernel_of_cokernel -> CategoryTheory.Abelian.monoIsKernelOfCokernel is a dubious translation:
-<too large>
-Case conversion may be inaccurate. Consider using '#align category_theory.abelian.mono_is_kernel_of_cokernel CategoryTheory.Abelian.monoIsKernelOfCokernelₓ'. -/
 /-- In an abelian category, a mono is the kernel of its cokernel. More precisely:
     If `f` is a monomorphism and `s` is some colimit cokernel cocone on `f`, then `f` is a kernel
     of `cofork.π s`. -/
@@ -642,12 +636,6 @@ abbrev pullbackToBiproduct : pullback f g ⟶ X ⊞ Y :=
 #align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproduct
 -/
 
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-Case conversion may be inaccurate. Consider using '#align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct_fork CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductForkₓ'. -/
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` induces a kernel cone on the map
     `biproduct X Y ⟶ Z` induced by `f` and `g`. A slightly more intuitive way to think of
     this may be that it induces an equalizer fork on the maps induced by `(f, 0)` and
@@ -657,12 +645,6 @@ abbrev pullbackToBiproductFork : KernelFork (biprod.desc f (-g)) :=
     rw [biprod.lift_desc, comp_neg, pullback.condition, add_right_neg]
 #align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct_fork CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductFork
 
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-Case conversion may be inaccurate. Consider using '#align category_theory.abelian.pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct CategoryTheory.Abelian.PullbackToBiproductIsKernel.isLimitPullbackToBiproductₓ'. -/
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` is a kernel of the map induced by
     `(f, -g)`. -/
 def isLimitPullbackToBiproduct : IsLimit (pullbackToBiproductFork f g) :=
@@ -692,12 +674,6 @@ abbrev biproductToPushout : Y ⊞ Z ⟶ pushout f g :=
 #align category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushout
 -/
 
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 /-- The canonical map `Y ⊞ Z ⟶ pushout f g` induces a cokernel cofork on the map
     `X ⟶ Y ⊞ Z` induced by `f` and `-g`. -/
 abbrev biproductToPushoutCofork : CokernelCofork (biprod.lift f (-g)) :=
@@ -705,12 +681,6 @@ abbrev biproductToPushoutCofork : CokernelCofork (biprod.lift f (-g)) :=
     rw [biprod.lift_desc, neg_comp, pushout.condition, add_right_neg]
 #align category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout_cofork CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushoutCofork
 
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 /-- The cofork induced by the canonical map `Y ⊞ Z ⟶ pushout f g` is in fact a colimit cokernel
     cofork. -/
 def isColimitBiproductToPushout : IsColimit (biproductToPushoutCofork f g) :=

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

@@ -185,15 +185,11 @@ def imageFactorisation {X Y : C} (f : X ⟶ Y) [IsIso (Abelian.coimageImageCompa
 -/
 
 instance [HasZeroObject C] {X Y : C} (f : X ⟶ Y) [Mono f]
-    [IsIso (Abelian.coimageImageComparison f)] : IsIso (imageMonoFactorisation f).e :=
-  by
-  rw [image_mono_factorisation_e']
-  exact is_iso.comp_is_iso
+    [IsIso (Abelian.coimageImageComparison f)] : IsIso (imageMonoFactorisation f).e := by
+  rw [image_mono_factorisation_e']; exact is_iso.comp_is_iso
 
-instance [HasZeroObject C] {X Y : C} (f : X ⟶ Y) [Epi f] : IsIso (imageMonoFactorisation f).m :=
-  by
-  dsimp
-  infer_instance
+instance [HasZeroObject C] {X Y : C} (f : X ⟶ Y) [Epi f] : IsIso (imageMonoFactorisation f).m := by
+  dsimp; infer_instance
 
 variable [∀ {X Y : C} (f : X ⟶ Y), IsIso (Abelian.coimageImageComparison f)]
 
@@ -963,12 +959,8 @@ def abelian : Abelian C :=
     HasFiniteProducts := by infer_instance
     HasKernels := by convert(by infer_instance : limits.has_kernels C)
     HasCokernels := by convert(by infer_instance : limits.has_cokernels C)
-    normalMonoOfMono := by
-      intros
-      convert normal_mono_of_mono f
-    normalEpiOfEpi := by
-      intros
-      convert normal_epi_of_epi f }
+    normalMonoOfMono := by intros ; convert normal_mono_of_mono f
+    normalEpiOfEpi := by intros ; convert normal_epi_of_epi f }
 #align category_theory.non_preadditive_abelian.abelian CategoryTheory.NonPreadditiveAbelian.abelian
 -/
 

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

@@ -527,10 +527,7 @@ variable {X Y : C} {f : X ⟶ Y}
 attribute [local instance] non_preadditive_abelian
 
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+<too large>
 Case conversion may be inaccurate. Consider using '#align category_theory.abelian.epi_is_cokernel_of_kernel CategoryTheory.Abelian.epiIsCokernelOfKernelₓ'. -/
 /-- In an abelian category, an epi is the cokernel of its kernel. More precisely:
     If `f` is an epimorphism and `s` is some limit kernel cone on `f`, then `f` is a cokernel
@@ -541,10 +538,7 @@ def epiIsCokernelOfKernel [Epi f] (s : Fork f 0) (h : IsLimit s) :
 #align category_theory.abelian.epi_is_cokernel_of_kernel CategoryTheory.Abelian.epiIsCokernelOfKernel
 
 /- warning: category_theory.abelian.mono_is_kernel_of_cokernel -> CategoryTheory.Abelian.monoIsKernelOfCokernel is a dubious translation:
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CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1) (CategoryTheory.Functor.category.{0, u1, 0, u2} CategoryTheory.Limits.WalkingParallelPair CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1))) (CategoryTheory.Functor.toPrefunctor.{u1, u1, u2, max u2 u1} C _inst_1 (CategoryTheory.Functor.{0, u1, 0, u2} CategoryTheory.Limits.WalkingParallelPair CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1) (CategoryTheory.Functor.category.{0, u1, 0, u2} CategoryTheory.Limits.WalkingParallelPair CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1) (CategoryTheory.Functor.const.{0, u1, 0, u2} CategoryTheory.Limits.WalkingParallelPair CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1)) (CategoryTheory.Limits.Cocone.pt.{0, u1, 0, u2} CategoryTheory.Limits.WalkingParallelPair CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1 (CategoryTheory.Limits.parallelPair.{u1, u2} C _inst_1 X Y f (OfNat.ofNat.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) 0 (Zero.toOfNat0.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) (CategoryTheory.Limits.HasZeroMorphisms.Zero.{u1, u2} C _inst_1 (CategoryTheory.NonPreadditiveAbelian.toHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.nonPreadditiveAbelian.{u1, u2} C _inst_1 _inst_2)) X Y)))) s))) CategoryTheory.Limits.WalkingParallelPair.one) (CategoryTheory.Limits.Cofork.π.{u1, u2} C _inst_1 X Y f (OfNat.ofNat.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) 0 (Zero.toOfNat0.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) (CategoryTheory.Limits.HasZeroMorphisms.Zero.{u1, u2} C _inst_1 (CategoryTheory.NonPreadditiveAbelian.toHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.nonPreadditiveAbelian.{u1, u2} C _inst_1 _inst_2)) X Y))) s) X f (CategoryTheory.Limits.CokernelCofork.condition.{u1, u2} C _inst_1 (CategoryTheory.NonPreadditiveAbelian.toHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.nonPreadditiveAbelian.{u1, u2} C _inst_1 _inst_2)) X Y f s)))
+<too large>
 Case conversion may be inaccurate. Consider using '#align category_theory.abelian.mono_is_kernel_of_cokernel CategoryTheory.Abelian.monoIsKernelOfCokernelₓ'. -/
 /-- In an abelian category, a mono is the kernel of its cokernel. More precisely:
     If `f` is a monomorphism and `s` is some colimit cokernel cocone on `f`, then `f` is a kernel

mathlib commit https://github.com/leanprover-community/mathlib/commit/75e7fca56381d056096ce5d05e938f63a6567828

@@ -565,7 +565,7 @@ def epiDesc [Epi f] {T : C} (g : X ⟶ T) (hg : kernel.ι f ≫ g = 0) : Y ⟶ T
 -/
 
 #print CategoryTheory.Abelian.comp_epiDesc /-
-@[simp, reassoc.1]
+@[simp, reassoc]
 theorem comp_epiDesc [Epi f] {T : C} (g : X ⟶ T) (hg : kernel.ι f ≫ g = 0) :
     f ≫ epiDesc f g hg = g :=
   (epiIsCokernelOfKernel _ (limit.isLimit _)).fac (CokernelCofork.ofπ _ hg) WalkingParallelPair.one
@@ -581,7 +581,7 @@ def monoLift [Mono f] {T : C} (g : T ⟶ Y) (hg : g ≫ cokernel.π f = 0) : T 
 -/
 
 #print CategoryTheory.Abelian.monoLift_comp /-
-@[simp, reassoc.1]
+@[simp, reassoc]
 theorem monoLift_comp [Mono f] {T : C} (g : T ⟶ Y) (hg : g ≫ cokernel.π f = 0) :
     monoLift f g hg ≫ f = g :=
   (monoIsKernelOfCokernel _ (colimit.isColimit _)).fac (KernelFork.ofι _ hg)

mathlib commit https://github.com/leanprover-community/mathlib/commit/a4f99eae998680d3a2c240da4a2b16354c85ee49

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel, Johan Commelin, Scott Morrison
 
 ! This file was ported from Lean 3 source module category_theory.abelian.basic
-! leanprover-community/mathlib commit 75be6b616681ab6ca66d798ead117e75cd64f125
+! leanprover-community/mathlib commit a5ff45a1c92c278b03b52459a620cfd9c49ebc80
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -293,12 +293,18 @@ namespace CategoryTheory.Abelian
 variable {C : Type u} [Category.{v} C] [Abelian C]
 
 #print CategoryTheory.Abelian.hasFiniteBiproducts /-
+-- Porting note: this should be an instance,
+-- but triggers https://github.com/leanprover/lean4/issues/2055
+-- We set it as a local instance instead.
+-- @[priority 100] instance
 /-- An abelian category has finite biproducts. -/
-instance (priority := 100) hasFiniteBiproducts : HasFiniteBiproducts C :=
+theorem hasFiniteBiproducts : HasFiniteBiproducts C :=
   Limits.HasFiniteBiproducts.of_hasFiniteProducts
 #align category_theory.abelian.has_finite_biproducts CategoryTheory.Abelian.hasFiniteBiproducts
 -/
 
+attribute [local instance] has_finite_biproducts
+
 #print CategoryTheory.Abelian.hasBinaryBiproducts /-
 instance (priority := 100) hasBinaryBiproducts : HasBinaryBiproducts C :=
   Limits.hasBinaryBiproducts_of_finite_biproducts _

mathlib commit https://github.com/leanprover-community/mathlib/commit/09079525fd01b3dda35e96adaa08d2f943e1648c

@@ -120,9 +120,9 @@ class Abelian extends Preadditive C, NormalMonoCategory C, NormalEpiCategory C w
 #align category_theory.abelian CategoryTheory.Abelian
 -/
 
-attribute [instance] abelian.has_finite_products
+attribute [instance 100] abelian.has_finite_products
 
-attribute [instance] abelian.has_kernels abelian.has_cokernels
+attribute [instance 100] abelian.has_kernels abelian.has_cokernels
 
 end CategoryTheory
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/5ec62c8106221a3f9160e4e4fcc3eed79fe213e9

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel, Johan Commelin, Scott Morrison
 
 ! This file was ported from Lean 3 source module category_theory.abelian.basic
-! leanprover-community/mathlib commit 8c75ef3517d4106e89fe524e6281d0b0545f47fc
+! leanprover-community/mathlib commit 75be6b616681ab6ca66d798ead117e75cd64f125
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -17,6 +17,9 @@ import Mathbin.CategoryTheory.Abelian.NonPreadditive
 /-!
 # Abelian categories
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 This file contains the definition and basic properties of abelian categories.
 
 There are many definitions of abelian category. Our definition is as follows:

mathlib commit https://github.com/leanprover-community/mathlib/commit/1a4df69ca1a9a0e5e26bfe12e2b92814216016d0

@@ -101,6 +101,7 @@ variable {C : Type u} [Category.{v} C]
 
 variable (C)
 
+#print CategoryTheory.Abelian /-
 /-- A (preadditive) category `C` is called abelian if it has all finite products,
 all kernels and cokernels, and if every monomorphism is the kernel of some morphism
 and every epimorphism is the cokernel of some morphism.
@@ -114,6 +115,7 @@ class Abelian extends Preadditive C, NormalMonoCategory C, NormalEpiCategory C w
   [HasKernels : HasKernels C]
   [HasCokernels : HasCokernels C]
 #align category_theory.abelian CategoryTheory.Abelian
+-/
 
 attribute [instance] abelian.has_finite_products
 
@@ -139,6 +141,7 @@ variable [Limits.HasKernels C] [Limits.HasCokernels C]
 
 namespace OfCoimageImageComparisonIsIso
 
+#print CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageMonoFactorisation /-
 /-- The factorisation of a morphism through its abelian image. -/
 @[simps]
 def imageMonoFactorisation {X Y : C} (f : X ⟶ Y) : MonoFactorisation f
@@ -149,7 +152,9 @@ def imageMonoFactorisation {X Y : C} (f : X ⟶ Y) : MonoFactorisation f
   e := kernel.lift _ f (cokernel.condition _)
   fac := kernel.lift_ι _ _ _
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.image_mono_factorisation CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageMonoFactorisation
+-/
 
+#print CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageMonoFactorisation_e' /-
 theorem imageMonoFactorisation_e' {X Y : C} (f : X ⟶ Y) :
     (imageMonoFactorisation f).e = cokernel.π _ ≫ Abelian.coimageImageComparison f :=
   by
@@ -157,7 +162,9 @@ theorem imageMonoFactorisation_e' {X Y : C} (f : X ⟶ Y) :
   simp only [abelian.coimage_image_comparison, image_mono_factorisation_e, category.assoc,
     cokernel.π_desc_assoc]
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.image_mono_factorisation_e' CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageMonoFactorisation_e'
+-/
 
+#print CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageFactorisation /-
 /-- If the coimage-image comparison morphism for a morphism `f` is an isomorphism,
 we obtain an image factorisation of `f`. -/
 def imageFactorisation {X Y : C} (f : X ⟶ Y) [IsIso (Abelian.coimageImageComparison f)] :
@@ -172,6 +179,7 @@ def imageFactorisation {X Y : C} (f : X ⟶ Y) [IsIso (Abelian.coimageImageCompa
         ext
         simp only [cokernel.π_desc_assoc, mono_factorisation.fac, image.fac] }
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.image_factorisation CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageFactorisation
+-/
 
 instance [HasZeroObject C] {X Y : C} (f : X ⟶ Y) [Mono f]
     [IsIso (Abelian.coimageImageComparison f)] : IsIso (imageMonoFactorisation f).e :=
@@ -186,15 +194,18 @@ instance [HasZeroObject C] {X Y : C} (f : X ⟶ Y) [Epi f] : IsIso (imageMonoFac
 
 variable [∀ {X Y : C} (f : X ⟶ Y), IsIso (Abelian.coimageImageComparison f)]
 
+#print CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.hasImages /-
 /-- A category in which coimage-image comparisons are all isomorphisms has images. -/
 theorem hasImages : HasImages C :=
   { HasImage := fun X Y f => { exists_image := ⟨imageFactorisation f⟩ } }
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.has_images CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.hasImages
+-/
 
 variable [Limits.HasFiniteProducts C]
 
 attribute [local instance] limits.has_finite_biproducts.of_has_finite_products
 
+#print CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.normalMonoCategory /-
 /-- A category with finite products in which coimage-image comparisons are all isomorphisms
 is a normal mono category.
 -/
@@ -218,7 +229,9 @@ def normalMonoCategory : NormalMonoCategory C
           rw [is_iso.inv_comp_eq, eq_comm]
           exact (image_mono_factorisation f).fac }
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.normal_mono_category CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.normalMonoCategory
+-/
 
+#print CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.normalEpiCategory /-
 /-- A category with finite products in which coimage-image comparisons are all isomorphisms
 is a normal epi category.
 -/
@@ -247,6 +260,7 @@ def normalEpiCategory : NormalEpiCategory C
           rw [is_iso.comp_inv_eq, is_iso.comp_inv_eq, eq_comm, ← image_mono_factorisation_e']
           exact (image_mono_factorisation f).fac }
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.normal_epi_category CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.normalEpiCategory
+-/
 
 end OfCoimageImageComparisonIsIso
 
@@ -257,6 +271,7 @@ attribute [local instance] of_coimage_image_comparison_is_iso.normal_mono_catego
 
 attribute [local instance] of_coimage_image_comparison_is_iso.normal_epi_category
 
+#print CategoryTheory.Abelian.ofCoimageImageComparisonIsIso /-
 /-- A preadditive category with kernels, cokernels, and finite products,
 in which the coimage-image comparison morphism is always an isomorphism,
 is an abelian category.
@@ -266,6 +281,7 @@ See <https://stacks.math.columbia.edu/tag/0109>.
 -/
 def ofCoimageImageComparisonIsIso : Abelian C where
 #align category_theory.abelian.of_coimage_image_comparison_is_iso CategoryTheory.Abelian.ofCoimageImageComparisonIsIso
+-/
 
 end CategoryTheory.Abelian
 
@@ -273,25 +289,33 @@ namespace CategoryTheory.Abelian
 
 variable {C : Type u} [Category.{v} C] [Abelian C]
 
+#print CategoryTheory.Abelian.hasFiniteBiproducts /-
 /-- An abelian category has finite biproducts. -/
 instance (priority := 100) hasFiniteBiproducts : HasFiniteBiproducts C :=
   Limits.HasFiniteBiproducts.of_hasFiniteProducts
 #align category_theory.abelian.has_finite_biproducts CategoryTheory.Abelian.hasFiniteBiproducts
+-/
 
+#print CategoryTheory.Abelian.hasBinaryBiproducts /-
 instance (priority := 100) hasBinaryBiproducts : HasBinaryBiproducts C :=
   Limits.hasBinaryBiproducts_of_finite_biproducts _
 #align category_theory.abelian.has_binary_biproducts CategoryTheory.Abelian.hasBinaryBiproducts
+-/
 
+#print CategoryTheory.Abelian.hasZeroObject /-
 instance (priority := 100) hasZeroObject : HasZeroObject C :=
   hasZeroObject_of_hasInitial_object
 #align category_theory.abelian.has_zero_object CategoryTheory.Abelian.hasZeroObject
+-/
 
 section ToNonPreadditiveAbelian
 
+#print CategoryTheory.Abelian.nonPreadditiveAbelian /-
 /-- Every abelian category is, in particular, `non_preadditive_abelian`. -/
 def nonPreadditiveAbelian : NonPreadditiveAbelian C :=
   { ‹Abelian C› with }
 #align category_theory.abelian.non_preadditive_abelian CategoryTheory.Abelian.nonPreadditiveAbelian
+-/
 
 end ToNonPreadditiveAbelian
 
@@ -307,14 +331,18 @@ variable {P Q : C} (f : P ⟶ Q)
 /-- The map `p : P ⟶ image f` is an epimorphism -/
 instance : Epi (Abelian.factorThruImage f) := by infer_instance
 
+#print CategoryTheory.Abelian.isIso_factorThruImage /-
 instance isIso_factorThruImage [Mono f] : IsIso (Abelian.factorThruImage f) := by infer_instance
 #align category_theory.abelian.is_iso_factor_thru_image CategoryTheory.Abelian.isIso_factorThruImage
+-/
 
 /-- The canonical morphism `i : coimage f ⟶ Q` is a monomorphism -/
 instance : Mono (Abelian.factorThruCoimage f) := by infer_instance
 
+#print CategoryTheory.Abelian.isIso_factorThruCoimage /-
 instance isIso_factorThruCoimage [Epi f] : IsIso (Abelian.factorThruCoimage f) := by infer_instance
 #align category_theory.abelian.is_iso_factor_thru_coimage CategoryTheory.Abelian.isIso_factorThruCoimage
+-/
 
 end
 
@@ -326,16 +354,20 @@ variable {P Q : C} (f : P ⟶ Q)
 
 section
 
+#print CategoryTheory.Abelian.mono_of_kernel_ι_eq_zero /-
 theorem mono_of_kernel_ι_eq_zero (h : kernel.ι f = 0) : Mono f :=
   mono_of_kernel_zero h
 #align category_theory.abelian.mono_of_kernel_ι_eq_zero CategoryTheory.Abelian.mono_of_kernel_ι_eq_zero
+-/
 
+#print CategoryTheory.Abelian.epi_of_cokernel_π_eq_zero /-
 theorem epi_of_cokernel_π_eq_zero (h : cokernel.π f = 0) : Epi f :=
   by
   apply normal_mono_category.epi_of_zero_cokernel _ (cokernel f)
   simp_rw [← h]
   exact is_colimit.of_iso_colimit (colimit.is_colimit (parallel_pair f 0)) (iso_of_π _)
 #align category_theory.abelian.epi_of_cokernel_π_eq_zero CategoryTheory.Abelian.epi_of_cokernel_π_eq_zero
+-/
 
 end
 
@@ -343,16 +375,21 @@ section
 
 variable {f}
 
+#print CategoryTheory.Abelian.image_ι_comp_eq_zero /-
 theorem image_ι_comp_eq_zero {R : C} {g : Q ⟶ R} (h : f ≫ g = 0) : Abelian.image.ι f ≫ g = 0 :=
   zero_of_epi_comp (Abelian.factorThruImage f) <| by simp [h]
 #align category_theory.abelian.image_ι_comp_eq_zero CategoryTheory.Abelian.image_ι_comp_eq_zero
+-/
 
+#print CategoryTheory.Abelian.comp_coimage_π_eq_zero /-
 theorem comp_coimage_π_eq_zero {R : C} {g : Q ⟶ R} (h : f ≫ g = 0) : f ≫ Abelian.coimage.π g = 0 :=
   zero_of_comp_mono (Abelian.factorThruCoimage g) <| by simp [h]
 #align category_theory.abelian.comp_coimage_π_eq_zero CategoryTheory.Abelian.comp_coimage_π_eq_zero
+-/
 
 end
 
+#print CategoryTheory.Abelian.imageStrongEpiMonoFactorisation /-
 /-- Factoring through the image is a strong epi-mono factorisation. -/
 @[simps]
 def imageStrongEpiMonoFactorisation : StrongEpiMonoFactorisation f
@@ -363,7 +400,9 @@ def imageStrongEpiMonoFactorisation : StrongEpiMonoFactorisation f
   e := Abelian.factorThruImage f
   e_strongEpi := strongEpi_of_epi _
 #align category_theory.abelian.image_strong_epi_mono_factorisation CategoryTheory.Abelian.imageStrongEpiMonoFactorisation
+-/
 
+#print CategoryTheory.Abelian.coimageStrongEpiMonoFactorisation /-
 /-- Factoring through the coimage is a strong epi-mono factorisation. -/
 @[simps]
 def coimageStrongEpiMonoFactorisation : StrongEpiMonoFactorisation f
@@ -374,6 +413,7 @@ def coimageStrongEpiMonoFactorisation : StrongEpiMonoFactorisation f
   e := coimage.π f
   e_strongEpi := strongEpi_of_epi _
 #align category_theory.abelian.coimage_strong_epi_mono_factorisation CategoryTheory.Abelian.coimageStrongEpiMonoFactorisation
+-/
 
 end Factor
 
@@ -406,18 +446,23 @@ instance : IsIso (coimageImageComparison f) :=
   change _ = _ ≫ (image_strong_epi_mono_factorisation f).m
   simp [-image_strong_epi_mono_factorisation_to_mono_factorisation_m]
 
+#print CategoryTheory.Abelian.coimageIsoImage /-
 /-- There is a canonical isomorphism between the abelian coimage and the abelian image of a
     morphism. -/
 abbrev coimageIsoImage : Abelian.coimage f ≅ Abelian.image f :=
   asIso (coimageImageComparison f)
 #align category_theory.abelian.coimage_iso_image CategoryTheory.Abelian.coimageIsoImage
+-/
 
+#print CategoryTheory.Abelian.coimageIsoImage' /-
 /-- There is a canonical isomorphism between the abelian coimage and the categorical image of a
     morphism. -/
 abbrev coimageIsoImage' : Abelian.coimage f ≅ image f :=
   IsImage.isoExt (coimageStrongEpiMonoFactorisation f).toMonoIsImage (Image.isImage f)
 #align category_theory.abelian.coimage_iso_image' CategoryTheory.Abelian.coimageIsoImage'
+-/
 
+#print CategoryTheory.Abelian.coimageIsoImage'_hom /-
 theorem coimageIsoImage'_hom :
     (coimageIsoImage' f).Hom =
       cokernel.desc _ (factorThruImage f) (by simp [← cancel_mono (limits.image.ι f)]) :=
@@ -427,24 +472,32 @@ theorem coimageIsoImage'_hom :
     category.assoc, is_image.lift_ι, coimage_strong_epi_mono_factorisation_to_mono_factorisation_m,
     limits.image.fac]
 #align category_theory.abelian.coimage_iso_image'_hom CategoryTheory.Abelian.coimageIsoImage'_hom
+-/
 
+#print CategoryTheory.Abelian.factorThruImage_comp_coimageIsoImage'_inv /-
 theorem factorThruImage_comp_coimageIsoImage'_inv :
     factorThruImage f ≫ (coimageIsoImage' f).inv = cokernel.π _ := by
   simp only [is_image.iso_ext_inv, image.is_image_lift, image.fac_lift,
     coimage_strong_epi_mono_factorisation_to_mono_factorisation_e]
 #align category_theory.abelian.factor_thru_image_comp_coimage_iso_image'_inv CategoryTheory.Abelian.factorThruImage_comp_coimageIsoImage'_inv
+-/
 
+#print CategoryTheory.Abelian.imageIsoImage /-
 /-- There is a canonical isomorphism between the abelian image and the categorical image of a
     morphism. -/
 abbrev imageIsoImage : Abelian.image f ≅ image f :=
   IsImage.isoExt (imageStrongEpiMonoFactorisation f).toMonoIsImage (Image.isImage f)
 #align category_theory.abelian.image_iso_image CategoryTheory.Abelian.imageIsoImage
+-/
 
+#print CategoryTheory.Abelian.imageIsoImage_hom_comp_image_ι /-
 theorem imageIsoImage_hom_comp_image_ι : (imageIsoImage f).Hom ≫ Limits.image.ι _ = kernel.ι _ := by
   simp only [is_image.iso_ext_hom, is_image.lift_ι,
     image_strong_epi_mono_factorisation_to_mono_factorisation_m]
 #align category_theory.abelian.image_iso_image_hom_comp_image_ι CategoryTheory.Abelian.imageIsoImage_hom_comp_image_ι
+-/
 
+#print CategoryTheory.Abelian.imageIsoImage_inv /-
 theorem imageIsoImage_inv :
     (imageIsoImage f).inv =
       kernel.lift _ (Limits.image.ι f) (by simp [← cancel_epi (factor_thru_image f)]) :=
@@ -454,6 +507,7 @@ theorem imageIsoImage_inv :
     image_strong_epi_mono_factorisation_to_mono_factorisation_e, category.assoc, kernel.lift_ι,
     limits.image.fac]
 #align category_theory.abelian.image_iso_image_inv CategoryTheory.Abelian.imageIsoImage_inv
+-/
 
 end Images
 
@@ -463,6 +517,12 @@ variable {X Y : C} {f : X ⟶ Y}
 
 attribute [local instance] non_preadditive_abelian
 
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+Case conversion may be inaccurate. Consider using '#align category_theory.abelian.epi_is_cokernel_of_kernel CategoryTheory.Abelian.epiIsCokernelOfKernelₓ'. -/
 /-- In an abelian category, an epi is the cokernel of its kernel. More precisely:
     If `f` is an epimorphism and `s` is some limit kernel cone on `f`, then `f` is a cokernel
     of `fork.ι s`. -/
@@ -471,6 +531,12 @@ def epiIsCokernelOfKernel [Epi f] (s : Fork f 0) (h : IsLimit s) :
   NonPreadditiveAbelian.epiIsCokernelOfKernel s h
 #align category_theory.abelian.epi_is_cokernel_of_kernel CategoryTheory.Abelian.epiIsCokernelOfKernel
 
+/- warning: category_theory.abelian.mono_is_kernel_of_cokernel -> CategoryTheory.Abelian.monoIsKernelOfCokernel is a dubious translation:
+lean 3 declaration is
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+but is expected to have type
+  forall {C : Type.{u2}} [_inst_1 : CategoryTheory.Category.{u1, u2} C] [_inst_2 : CategoryTheory.Abelian.{u1, u2} C _inst_1] {X : C} {Y : C} {f : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y} [_inst_3 : CategoryTheory.Mono.{u1, u2} C _inst_1 X Y f] (s : CategoryTheory.Limits.Cofork.{u1, u2} C _inst_1 X Y f (OfNat.ofNat.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) 0 (Zero.toOfNat0.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) (CategoryTheory.Limits.HasZeroMorphisms.Zero.{u1, u2} C _inst_1 (CategoryTheory.NonPreadditiveAbelian.toHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.nonPreadditiveAbelian.{u1, u2} C _inst_1 _inst_2)) X Y)))), 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+Case conversion may be inaccurate. Consider using '#align category_theory.abelian.mono_is_kernel_of_cokernel CategoryTheory.Abelian.monoIsKernelOfCokernelₓ'. -/
 /-- In an abelian category, a mono is the kernel of its cokernel. More precisely:
     If `f` is a monomorphism and `s` is some colimit cokernel cocone on `f`, then `f` is a kernel
     of `cofork.π s`. -/
@@ -481,64 +547,84 @@ def monoIsKernelOfCokernel [Mono f] (s : Cofork f 0) (h : IsColimit s) :
 
 variable (f)
 
+#print CategoryTheory.Abelian.epiDesc /-
 /-- In an abelian category, any morphism that turns to zero when precomposed with the kernel of an
     epimorphism factors through that epimorphism. -/
 def epiDesc [Epi f] {T : C} (g : X ⟶ T) (hg : kernel.ι f ≫ g = 0) : Y ⟶ T :=
   (epiIsCokernelOfKernel _ (limit.isLimit _)).desc (CokernelCofork.ofπ _ hg)
 #align category_theory.abelian.epi_desc CategoryTheory.Abelian.epiDesc
+-/
 
+#print CategoryTheory.Abelian.comp_epiDesc /-
 @[simp, reassoc.1]
 theorem comp_epiDesc [Epi f] {T : C} (g : X ⟶ T) (hg : kernel.ι f ≫ g = 0) :
     f ≫ epiDesc f g hg = g :=
   (epiIsCokernelOfKernel _ (limit.isLimit _)).fac (CokernelCofork.ofπ _ hg) WalkingParallelPair.one
 #align category_theory.abelian.comp_epi_desc CategoryTheory.Abelian.comp_epiDesc
+-/
 
+#print CategoryTheory.Abelian.monoLift /-
 /-- In an abelian category, any morphism that turns to zero when postcomposed with the cokernel of a
     monomorphism factors through that monomorphism. -/
 def monoLift [Mono f] {T : C} (g : T ⟶ Y) (hg : g ≫ cokernel.π f = 0) : T ⟶ X :=
   (monoIsKernelOfCokernel _ (colimit.isColimit _)).lift (KernelFork.ofι _ hg)
 #align category_theory.abelian.mono_lift CategoryTheory.Abelian.monoLift
+-/
 
+#print CategoryTheory.Abelian.monoLift_comp /-
 @[simp, reassoc.1]
 theorem monoLift_comp [Mono f] {T : C} (g : T ⟶ Y) (hg : g ≫ cokernel.π f = 0) :
     monoLift f g hg ≫ f = g :=
   (monoIsKernelOfCokernel _ (colimit.isColimit _)).fac (KernelFork.ofι _ hg)
     WalkingParallelPair.zero
 #align category_theory.abelian.mono_lift_comp CategoryTheory.Abelian.monoLift_comp
+-/
 
 end CokernelOfKernel
 
 section
 
+#print CategoryTheory.Abelian.hasEqualizers /-
 instance (priority := 100) hasEqualizers : HasEqualizers C :=
   Preadditive.hasEqualizers_of_hasKernels
 #align category_theory.abelian.has_equalizers CategoryTheory.Abelian.hasEqualizers
+-/
 
+#print CategoryTheory.Abelian.hasPullbacks /-
 /-- Any abelian category has pullbacks -/
 instance (priority := 100) hasPullbacks : HasPullbacks C :=
   hasPullbacks_of_hasBinaryProducts_of_hasEqualizers C
 #align category_theory.abelian.has_pullbacks CategoryTheory.Abelian.hasPullbacks
+-/
 
 end
 
 section
 
+#print CategoryTheory.Abelian.hasCoequalizers /-
 instance (priority := 100) hasCoequalizers : HasCoequalizers C :=
   Preadditive.hasCoequalizers_of_hasCokernels
 #align category_theory.abelian.has_coequalizers CategoryTheory.Abelian.hasCoequalizers
+-/
 
+#print CategoryTheory.Abelian.hasPushouts /-
 /-- Any abelian category has pushouts -/
 instance (priority := 100) hasPushouts : HasPushouts C :=
   hasPushouts_of_hasBinaryCoproducts_of_hasCoequalizers C
 #align category_theory.abelian.has_pushouts CategoryTheory.Abelian.hasPushouts
+-/
 
+#print CategoryTheory.Abelian.hasFiniteLimits /-
 instance (priority := 100) hasFiniteLimits : HasFiniteLimits C :=
   Limits.hasFiniteLimits_of_hasEqualizers_and_finite_products
 #align category_theory.abelian.has_finite_limits CategoryTheory.Abelian.hasFiniteLimits
+-/
 
+#print CategoryTheory.Abelian.hasFiniteColimits /-
 instance (priority := 100) hasFiniteColimits : HasFiniteColimits C :=
   Limits.hasFiniteColimits_of_hasCoequalizers_and_finite_coproducts
 #align category_theory.abelian.has_finite_colimits CategoryTheory.Abelian.hasFiniteColimits
+-/
 
 end
 
@@ -550,11 +636,19 @@ variable [Limits.HasPullbacks C] {X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z)
     We will need it in the proof that the pullback of an epimorphism is an epimorpism. -/
 
 
+#print CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproduct /-
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` -/
 abbrev pullbackToBiproduct : pullback f g ⟶ X ⊞ Y :=
   biprod.lift pullback.fst pullback.snd
 #align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproduct
+-/
 
+/- warning: category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct_fork -> CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductFork is a dubious translation:
+lean 3 declaration is
+  forall {C : Type.{u2}} [_inst_1 : CategoryTheory.Category.{u1, u2} C] [_inst_2 : CategoryTheory.Abelian.{u1, u2} C _inst_1] [_inst_3 : CategoryTheory.Limits.HasPullbacks.{u1, u2} C _inst_1] {X : C} {Y : C} {Z : C} (f : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z) (g : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) Y Z), CategoryTheory.Limits.KernelFork.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) (CategoryTheory.Limits.biprod.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) X Y (CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproduct._proof_2.{u2, u1} C _inst_1 _inst_2 X Y)) Z (CategoryTheory.Limits.biprod.desc.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) Z X Y (CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproduct._proof_2.{u2, u1} C _inst_1 _inst_2 X Y) f (Neg.neg.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) Y Z) (SubNegMonoid.toHasNeg.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) Y Z) (AddGroup.toSubNegMonoid.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) Y Z) (AddCommGroup.toAddGroup.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) Y Z) (CategoryTheory.Preadditive.homGroup.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2) Y Z)))) g))
+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct_fork CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductForkₓ'. -/
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` induces a kernel cone on the map
     `biproduct X Y ⟶ Z` induced by `f` and `g`. A slightly more intuitive way to think of
     this may be that it induces an equalizer fork on the maps induced by `(f, 0)` and
@@ -564,6 +658,12 @@ abbrev pullbackToBiproductFork : KernelFork (biprod.desc f (-g)) :=
     rw [biprod.lift_desc, comp_neg, pullback.condition, add_right_neg]
 #align category_theory.abelian.pullback_to_biproduct_is_kernel.pullback_to_biproduct_fork CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductFork
 
+/- warning: category_theory.abelian.pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct -> CategoryTheory.Abelian.PullbackToBiproductIsKernel.isLimitPullbackToBiproduct is a dubious translation:
+lean 3 declaration is
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+but is expected to have type
+  forall {C : Type.{u2}} [_inst_1 : CategoryTheory.Category.{u1, u2} C] [_inst_2 : CategoryTheory.Abelian.{u1, u2} C _inst_1] [_inst_3 : CategoryTheory.Limits.HasPullbacks.{u1, u2} C _inst_1] {X : C} {Y : C} {Z : C} (f : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z) (g : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) Y Z), CategoryTheory.Limits.IsLimit.{0, u1, 0, u2} CategoryTheory.Limits.WalkingParallelPair CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1 (CategoryTheory.Limits.parallelPair.{u1, u2} C _inst_1 (CategoryTheory.Limits.biprod.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) X Y (CategoryTheory.Limits.HasBinaryBiproducts.has_binary_biproduct.{u1, u2} C 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_inst_2) X Y)) Z)))) (CategoryTheory.Abelian.PullbackToBiproductIsKernel.pullbackToBiproductFork.{u1, u2} C _inst_1 _inst_2 _inst_3 X Y Z f g)
+Case conversion may be inaccurate. Consider using '#align category_theory.abelian.pullback_to_biproduct_is_kernel.is_limit_pullback_to_biproduct CategoryTheory.Abelian.PullbackToBiproductIsKernel.isLimitPullbackToBiproductₓ'. -/
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` is a kernel of the map induced by
     `(f, -g)`. -/
 def isLimitPullbackToBiproduct : IsLimit (pullbackToBiproductFork f g) :=
@@ -586,11 +686,19 @@ namespace BiproductToPushoutIsCokernel
 
 variable [Limits.HasPushouts C] {W X Y Z : C} (f : X ⟶ Y) (g : X ⟶ Z)
 
+#print CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushout /-
 /-- The canonical map `Y ⊞ Z ⟶ pushout f g` -/
 abbrev biproductToPushout : Y ⊞ Z ⟶ pushout f g :=
   biprod.desc pushout.inl pushout.inr
 #align category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushout
+-/
 
+/- warning: category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout_cofork -> CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushoutCofork is a dubious translation:
+lean 3 declaration is
+  forall {C : Type.{u2}} [_inst_1 : CategoryTheory.Category.{u1, u2} C] [_inst_2 : CategoryTheory.Abelian.{u1, u2} C _inst_1] [_inst_3 : CategoryTheory.Limits.HasPushouts.{u1, u2} C _inst_1] {X : C} {Y : C} {Z : C} (f : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) (g : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z), CategoryTheory.Limits.CokernelCofork.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) X (CategoryTheory.Limits.biprod.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) Y Z (CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushout._proof_1.{u2, u1} C _inst_1 _inst_2 Y Z)) (CategoryTheory.Limits.biprod.lift.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) X Y Z (CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushout._proof_1.{u2, u1} C _inst_1 _inst_2 Y Z) f (Neg.neg.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z) (SubNegMonoid.toHasNeg.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z) (AddGroup.toSubNegMonoid.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z) (AddCommGroup.toAddGroup.{u1} (Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z) (CategoryTheory.Preadditive.homGroup.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2) X Z)))) g))
+but is expected to have type
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+Case conversion may be inaccurate. Consider using '#align category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout_cofork CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushoutCoforkₓ'. -/
 /-- The canonical map `Y ⊞ Z ⟶ pushout f g` induces a cokernel cofork on the map
     `X ⟶ Y ⊞ Z` induced by `f` and `-g`. -/
 abbrev biproductToPushoutCofork : CokernelCofork (biprod.lift f (-g)) :=
@@ -598,6 +706,12 @@ abbrev biproductToPushoutCofork : CokernelCofork (biprod.lift f (-g)) :=
     rw [biprod.lift_desc, neg_comp, pushout.condition, add_right_neg]
 #align category_theory.abelian.biproduct_to_pushout_is_cokernel.biproduct_to_pushout_cofork CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushoutCofork
 
+/- warning: category_theory.abelian.biproduct_to_pushout_is_cokernel.is_colimit_biproduct_to_pushout -> CategoryTheory.Abelian.BiproductToPushoutIsCokernel.isColimitBiproductToPushout is a dubious translation:
+lean 3 declaration is
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+but is expected to have type
+  forall {C : Type.{u2}} [_inst_1 : CategoryTheory.Category.{u1, u2} C] [_inst_2 : CategoryTheory.Abelian.{u1, u2} C _inst_1] [_inst_3 : CategoryTheory.Limits.HasPushouts.{u1, u2} C _inst_1] {X : C} {Y : C} {Z : C} (f : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Y) (g : Quiver.Hom.{succ u1, u2} C (CategoryTheory.CategoryStruct.toQuiver.{u1, u2} C (CategoryTheory.Category.toCategoryStruct.{u1, u2} C _inst_1)) X Z), CategoryTheory.Limits.IsColimit.{0, u1, 0, u2} CategoryTheory.Limits.WalkingParallelPair CategoryTheory.Limits.walkingParallelPairHomCategory C _inst_1 (CategoryTheory.Limits.parallelPair.{u1, u2} C _inst_1 X (CategoryTheory.Limits.biprod.{u1, u2} C _inst_1 (CategoryTheory.Preadditive.preadditiveHasZeroMorphisms.{u1, u2} C _inst_1 (CategoryTheory.Abelian.toPreadditive.{u1, u2} C _inst_1 _inst_2)) Y Z (CategoryTheory.Limits.HasBinaryBiproducts.has_binary_biproduct.{u1, u2} C 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_inst_2) Y Z)))))) (CategoryTheory.Abelian.BiproductToPushoutIsCokernel.biproductToPushoutCofork.{u1, u2} C _inst_1 _inst_2 _inst_3 X Y Z f g)
+Case conversion may be inaccurate. Consider using '#align category_theory.abelian.biproduct_to_pushout_is_cokernel.is_colimit_biproduct_to_pushout CategoryTheory.Abelian.BiproductToPushoutIsCokernel.isColimitBiproductToPushoutₓ'. -/
 /-- The cofork induced by the canonical map `Y ⊞ Z ⟶ pushout f g` is in fact a colimit cokernel
     cofork. -/
 def isColimitBiproductToPushout : IsColimit (biproductToPushoutCofork f g) :=
@@ -616,6 +730,7 @@ section EpiPullback
 
 variable [Limits.HasPullbacks C] {W X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z)
 
+#print CategoryTheory.Abelian.epi_pullback_of_epi_f /-
 /-- In an abelian category, the pullback of an epimorphism is an epimorphism.
     Proof from [aluffi2016, IX.2.3], cf. [borceux-vol2, 1.7.6] -/
 instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y) :=
@@ -655,7 +770,9 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
       _ = 0 := has_zero_morphisms.comp_zero _ _
       
 #align category_theory.abelian.epi_pullback_of_epi_f CategoryTheory.Abelian.epi_pullback_of_epi_f
+-/
 
+#print CategoryTheory.Abelian.epi_pullback_of_epi_g /-
 /-- In an abelian category, the pullback of an epimorphism is an epimorphism. -/
 instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X) :=
   -- It will suffice to consider some morphism e : X ⟶ R such that
@@ -694,21 +811,27 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
       _ = 0 := has_zero_morphisms.comp_zero _ _
       
 #align category_theory.abelian.epi_pullback_of_epi_g CategoryTheory.Abelian.epi_pullback_of_epi_g
+-/
 
+#print CategoryTheory.Abelian.epi_snd_of_isLimit /-
 theorem epi_snd_of_isLimit [Epi f] {s : PullbackCone f g} (hs : IsLimit s) : Epi s.snd :=
   by
   convert epi_of_epi_fac (is_limit.cone_point_unique_up_to_iso_hom_comp (limit.is_limit _) hs _)
   · rfl
   · exact abelian.epi_pullback_of_epi_f _ _
 #align category_theory.abelian.epi_snd_of_is_limit CategoryTheory.Abelian.epi_snd_of_isLimit
+-/
 
+#print CategoryTheory.Abelian.epi_fst_of_isLimit /-
 theorem epi_fst_of_isLimit [Epi g] {s : PullbackCone f g} (hs : IsLimit s) : Epi s.fst :=
   by
   convert epi_of_epi_fac (is_limit.cone_point_unique_up_to_iso_hom_comp (limit.is_limit _) hs _)
   · rfl
   · exact abelian.epi_pullback_of_epi_g _ _
 #align category_theory.abelian.epi_fst_of_is_limit CategoryTheory.Abelian.epi_fst_of_isLimit
+-/
 
+#print CategoryTheory.Abelian.epi_fst_of_factor_thru_epi_mono_factorization /-
 /-- Suppose `f` and `g` are two morphisms with a common codomain and suppose we have written `g` as
     an epimorphism followed by a monomorphism. If `f` factors through the mono part of this
     factorization, then any pullback of `g` along `f` is an epimorphism. -/
@@ -717,6 +840,7 @@ theorem epi_fst_of_factor_thru_epi_mono_factorization (g₁ : Y ⟶ W) [Epi g₁
     Epi t.fst := by
   apply epi_fst_of_is_limit _ _ (pullback_cone.is_limit_of_factors f g g₂ f' g₁ hf hg t ht)
 #align category_theory.abelian.epi_fst_of_factor_thru_epi_mono_factorization CategoryTheory.Abelian.epi_fst_of_factor_thru_epi_mono_factorization
+-/
 
 end EpiPullback
 
@@ -724,6 +848,7 @@ section MonoPushout
 
 variable [Limits.HasPushouts C] {W X Y Z : C} (f : X ⟶ Y) (g : X ⟶ Z)
 
+#print CategoryTheory.Abelian.mono_pushout_of_mono_f /-
 instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g) :=
   mono_of_cancel_zero _ fun R e h =>
     by
@@ -750,7 +875,9 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       _ = 0 := zero_comp
       
 #align category_theory.abelian.mono_pushout_of_mono_f CategoryTheory.Abelian.mono_pushout_of_mono_f
+-/
 
+#print CategoryTheory.Abelian.mono_pushout_of_mono_g /-
 instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g) :=
   mono_of_cancel_zero _ fun R e h =>
     by
@@ -777,7 +904,9 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
       _ = 0 := zero_comp
       
 #align category_theory.abelian.mono_pushout_of_mono_g CategoryTheory.Abelian.mono_pushout_of_mono_g
+-/
 
+#print CategoryTheory.Abelian.mono_inr_of_isColimit /-
 theorem mono_inr_of_isColimit [Mono f] {s : PushoutCocone f g} (hs : IsColimit s) : Mono s.inr :=
   by
   convert mono_of_mono_fac
@@ -785,7 +914,9 @@ theorem mono_inr_of_isColimit [Mono f] {s : PushoutCocone f g} (hs : IsColimit s
   · rfl
   · exact abelian.mono_pushout_of_mono_f _ _
 #align category_theory.abelian.mono_inr_of_is_colimit CategoryTheory.Abelian.mono_inr_of_isColimit
+-/
 
+#print CategoryTheory.Abelian.mono_inl_of_isColimit /-
 theorem mono_inl_of_isColimit [Mono g] {s : PushoutCocone f g} (hs : IsColimit s) : Mono s.inl :=
   by
   convert mono_of_mono_fac
@@ -793,7 +924,9 @@ theorem mono_inl_of_isColimit [Mono g] {s : PushoutCocone f g} (hs : IsColimit s
   · rfl
   · exact abelian.mono_pushout_of_mono_g _ _
 #align category_theory.abelian.mono_inl_of_is_colimit CategoryTheory.Abelian.mono_inl_of_isColimit
+-/
 
+#print CategoryTheory.Abelian.mono_inl_of_factor_thru_epi_mono_factorization /-
 /-- Suppose `f` and `g` are two morphisms with a common domain and suppose we have written `g` as
     an epimorphism followed by a monomorphism. If `f` factors through the epi part of this
     factorization, then any pushout of `g` along `f` is a monomorphism. -/
@@ -802,6 +935,7 @@ theorem mono_inl_of_factor_thru_epi_mono_factorization (f : X ⟶ Y) (g : X ⟶
     (t : PushoutCocone f g) (ht : IsColimit t) : Mono t.inl := by
   apply mono_inl_of_is_colimit _ _ (pushout_cocone.is_colimit_of_factors _ _ _ _ _ hf hg t ht)
 #align category_theory.abelian.mono_inl_of_factor_thru_epi_mono_factorization CategoryTheory.Abelian.mono_inl_of_factor_thru_epi_mono_factorization
+-/
 
 end MonoPushout
 
@@ -811,6 +945,7 @@ namespace CategoryTheory.NonPreadditiveAbelian
 
 variable (C : Type u) [Category.{v} C] [NonPreadditiveAbelian C]
 
+#print CategoryTheory.NonPreadditiveAbelian.abelian /-
 /-- Every non_preadditive_abelian category can be promoted to an abelian category. -/
 def abelian : Abelian C :=
   {/- We need the `convert`s here because the instances we have are slightly different from the
@@ -832,6 +967,7 @@ def abelian : Abelian C :=
       intros
       convert normal_epi_of_epi f }
 #align category_theory.non_preadditive_abelian.abelian CategoryTheory.NonPreadditiveAbelian.abelian
+-/
 
 end CategoryTheory.NonPreadditiveAbelian
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/ce7e9d53d4bbc38065db3b595cd5bd73c323bc1d

@@ -399,8 +399,7 @@ See `category_theory.abelian.of_coimage_image_comparison_is_iso` for the convers
 -/
 instance : IsIso (coimageImageComparison f) :=
   by
-  convert
-    is_iso.of_iso
+  convert is_iso.of_iso
       (is_image.iso_ext (coimage_strong_epi_mono_factorisation f).toMonoIsImage
         (image_strong_epi_mono_factorisation f).toMonoIsImage)
   ext
@@ -781,16 +780,16 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
 
 theorem mono_inr_of_isColimit [Mono f] {s : PushoutCocone f g} (hs : IsColimit s) : Mono s.inr :=
   by
-  convert
-    mono_of_mono_fac (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
+  convert mono_of_mono_fac
+      (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
   · rfl
   · exact abelian.mono_pushout_of_mono_f _ _
 #align category_theory.abelian.mono_inr_of_is_colimit CategoryTheory.Abelian.mono_inr_of_isColimit
 
 theorem mono_inl_of_isColimit [Mono g] {s : PushoutCocone f g} (hs : IsColimit s) : Mono s.inl :=
   by
-  convert
-    mono_of_mono_fac (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
+  convert mono_of_mono_fac
+      (is_colimit.comp_cocone_point_unique_up_to_iso_hom hs (colimit.is_colimit _) _)
   · rfl
   · exact abelian.mono_pushout_of_mono_g _ _
 #align category_theory.abelian.mono_inl_of_is_colimit CategoryTheory.Abelian.mono_inl_of_isColimit
@@ -824,8 +823,8 @@ def abelian : Abelian C :=
        the goal it creates for the two instances of `has_zero_morphisms`, and the proof is complete. -/
     NonPreadditiveAbelian.preadditive with
     HasFiniteProducts := by infer_instance
-    HasKernels := by convert (by infer_instance : limits.has_kernels C)
-    HasCokernels := by convert (by infer_instance : limits.has_cokernels C)
+    HasKernels := by convert(by infer_instance : limits.has_kernels C)
+    HasCokernels := by convert(by infer_instance : limits.has_cokernels C)
     normalMonoOfMono := by
       intros
       convert normal_mono_of_mono f

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

@@ -165,7 +165,7 @@ def imageFactorisation {X Y : C} (f : X ⟶ Y) [IsIso (Abelian.coimageImageCompa
   f := imageMonoFactorisation f
   IsImage :=
     { lift := fun F => inv (Abelian.coimageImageComparison f) ≫ cokernel.desc _ F.e F.kernel_ι_comp
-      lift_fac' := fun F =>
+      lift_fac := fun F =>
         by
         simp only [image_mono_factorisation_m, is_iso.inv_comp_eq, category.assoc,
           abelian.coimage_image_comparison]

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

@@ -147,7 +147,7 @@ def imageMonoFactorisation {X Y : C} (f : X ⟶ Y) : MonoFactorisation f
   m := kernel.ι _
   m_mono := inferInstance
   e := kernel.lift _ f (cokernel.condition _)
-  fac' := kernel.lift_ι _ _ _
+  fac := kernel.lift_ι _ _ _
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.image_mono_factorisation CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageMonoFactorisation
 
 theorem imageMonoFactorisation_e' {X Y : C} (f : X ⟶ Y) :
@@ -275,11 +275,11 @@ variable {C : Type u} [Category.{v} C] [Abelian C]
 
 /-- An abelian category has finite biproducts. -/
 instance (priority := 100) hasFiniteBiproducts : HasFiniteBiproducts C :=
-  Limits.HasFiniteBiproducts.ofHasFiniteProducts
+  Limits.HasFiniteBiproducts.of_hasFiniteProducts
 #align category_theory.abelian.has_finite_biproducts CategoryTheory.Abelian.hasFiniteBiproducts
 
 instance (priority := 100) hasBinaryBiproducts : HasBinaryBiproducts C :=
-  Limits.hasBinaryBiproductsOfFiniteBiproducts _
+  Limits.hasBinaryBiproducts_of_finite_biproducts _
 #align category_theory.abelian.has_binary_biproducts CategoryTheory.Abelian.hasBinaryBiproducts
 
 instance (priority := 100) hasZeroObject : HasZeroObject C :=
@@ -534,11 +534,11 @@ instance (priority := 100) hasPushouts : HasPushouts C :=
 #align category_theory.abelian.has_pushouts CategoryTheory.Abelian.hasPushouts
 
 instance (priority := 100) hasFiniteLimits : HasFiniteLimits C :=
-  Limits.hasFiniteLimitsOfHasEqualizersAndFiniteProducts
+  Limits.hasFiniteLimits_of_hasEqualizers_and_finite_products
 #align category_theory.abelian.has_finite_limits CategoryTheory.Abelian.hasFiniteLimits
 
 instance (priority := 100) hasFiniteColimits : HasFiniteColimits C :=
-  Limits.hasFiniteColimitsOfHasCoequalizersAndFiniteCoproducts
+  Limits.hasFiniteColimits_of_hasCoequalizers_and_finite_coproducts
 #align category_theory.abelian.has_finite_colimits CategoryTheory.Abelian.hasFiniteColimits
 
 end

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

Purely automatic replacement. If this is in any way controversial; I'm happy to just close this PR.

@@ -787,9 +787,10 @@ def abelian : Abelian C :=
        case of `NonPreadditiveAbelian`, this instance is an explicit argument. However, in the case
        of `abelian`, the `HasZeroMorphisms` instance is derived from `Preadditive`. So we need to
        transform an instance of "has kernels with NonPreadditiveAbelian.HasZeroMorphisms" to an
-       instance of "has kernels with NonPreadditiveAbelian.Preadditive.HasZeroMorphisms". Luckily,
-       we have a `subsingleton` instance for `HasZeroMorphisms`, so `convert` can immediately close
-       the goal it creates for the two instances of `HasZeroMorphisms`, and the proof is complete.-/
+       instance of "has kernels with NonPreadditiveAbelian.Preadditive.HasZeroMorphisms".
+       Luckily, we have a `subsingleton` instance for `HasZeroMorphisms`, so `convert` can
+       immediately close the goal it creates for the two instances of `HasZeroMorphisms`,
+       and the proof is complete. -/
     NonPreadditiveAbelian.preadditive with
     has_finite_products := by infer_instance
     has_kernels := by convert (by infer_instance : Limits.HasKernels C)

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)

@@ -95,7 +95,6 @@ universe v u
 namespace CategoryTheory
 
 variable {C : Type u} [Category.{v} C]
-
 variable (C)
 
 /-- A (preadditive) category `C` is called abelian if it has all finite products,
@@ -130,7 +129,6 @@ is an abelian category.
 namespace CategoryTheory.Abelian
 
 variable {C : Type u} [Category.{v} C] [Preadditive C]
-
 variable [Limits.HasKernels C] [Limits.HasCokernels C]
 
 namespace OfCoimageImageComparisonIsIso

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

@@ -620,7 +620,7 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
     -- Consider the morphism u := (0, e) : X ⊞ Y⟶ R.
     let u := biprod.desc (0 : X ⟶ R) e
     -- The composite pullback f g ⟶ X ⊞ Y ⟶ R is zero by assumption.
-    have hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0 := by simpa
+    have hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0 := by simpa [u]
     -- pullback_to_biproduct f g is a kernel of (f, -g), so (f, -g) is a
     -- cokernel of pullback_to_biproduct f g
     have :=
@@ -628,7 +628,7 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
         (PullbackToBiproductIsKernel.isLimitPullbackToBiproduct f g)
     -- We use this fact to obtain a factorization of u through (f, -g) via some d : Z ⟶ R.
     obtain ⟨d, hd⟩ := CokernelCofork.IsColimit.desc' this u hu
-    dsimp at d; dsimp at hd
+    dsimp at d; dsimp [u] at hd
     -- But then f ≫ d = 0:
     have : f ≫ d = 0 := calc
       f ≫ d = (biprod.inl ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inl_desc]
@@ -653,7 +653,7 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
     -- Consider the morphism u := (e, 0) : X ⊞ Y ⟶ R.
     let u := biprod.desc e (0 : Y ⟶ R)
     -- The composite pullback f g ⟶ X ⊞ Y ⟶ R is zero by assumption.
-    have hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0 := by simpa
+    have hu : PullbackToBiproductIsKernel.pullbackToBiproduct f g ≫ u = 0 := by simpa [u]
     -- pullback_to_biproduct f g is a kernel of (f, -g), so (f, -g) is a
     -- cokernel of pullback_to_biproduct f g
     have :=
@@ -661,7 +661,7 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
         (PullbackToBiproductIsKernel.isLimitPullbackToBiproduct f g)
     -- We use this fact to obtain a factorization of u through (f, -g) via some d : Z ⟶ R.
     obtain ⟨d, hd⟩ := CokernelCofork.IsColimit.desc' this u hu
-    dsimp at d; dsimp at hd
+    dsimp at d; dsimp [u] at hd
     -- But then (-g) ≫ d = 0:
     have : (-g) ≫ d = 0 := calc
       (-g) ≫ d = (biprod.inr ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inr_desc]
@@ -708,13 +708,13 @@ variable [Limits.HasPushouts C] {W X Y Z : C} (f : X ⟶ Y) (g : X ⟶ Z)
 instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g) :=
   mono_of_cancel_zero _ fun {R} e h => by
     let u := biprod.lift (0 : R ⟶ Y) e
-    have hu : u ≫ BiproductToPushoutIsCokernel.biproductToPushout f g = 0 := by simpa
+    have hu : u ≫ BiproductToPushoutIsCokernel.biproductToPushout f g = 0 := by simpa [u]
     have :=
       monoIsKernelOfCokernel _
         (BiproductToPushoutIsCokernel.isColimitBiproductToPushout f g)
     obtain ⟨d, hd⟩ := KernelFork.IsLimit.lift' this u hu
     dsimp at d
-    dsimp at hd
+    dsimp [u] at hd
     have : d ≫ f = 0 := calc
       d ≫ f = d ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [biprod.lift_fst]
       _ = u ≫ biprod.fst := by rw [← Category.assoc, hd]
@@ -731,13 +731,13 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
 instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g) :=
   mono_of_cancel_zero _ fun {R} e h => by
     let u := biprod.lift e (0 : R ⟶ Z)
-    have hu : u ≫ BiproductToPushoutIsCokernel.biproductToPushout f g = 0 := by simpa
+    have hu : u ≫ BiproductToPushoutIsCokernel.biproductToPushout f g = 0 := by simpa [u]
     have :=
       monoIsKernelOfCokernel _
         (BiproductToPushoutIsCokernel.isColimitBiproductToPushout f g)
     obtain ⟨d, hd⟩ := KernelFork.IsLimit.lift' this u hu
     dsimp at d
-    dsimp at hd
+    dsimp [u] at hd
     have : d ≫ (-g) = 0 := calc
       d ≫ (-g) = d ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [biprod.lift_snd]
       _ = biprod.lift e (0 : R ⟶ Z) ≫ biprod.snd := by rw [← Category.assoc, hd]

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>

@@ -630,8 +630,7 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
     obtain ⟨d, hd⟩ := CokernelCofork.IsColimit.desc' this u hu
     dsimp at d; dsimp at hd
     -- But then f ≫ d = 0:
-    have : f ≫ d = 0;
-    calc
+    have : f ≫ d = 0 := calc
       f ≫ d = (biprod.inl ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inl_desc]
       _ = biprod.inl ≫ u := by rw [Category.assoc, hd]
       _ = 0 := biprod.inl_desc _ _
@@ -664,8 +663,7 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
     obtain ⟨d, hd⟩ := CokernelCofork.IsColimit.desc' this u hu
     dsimp at d; dsimp at hd
     -- But then (-g) ≫ d = 0:
-    have : (-g) ≫ d = 0;
-    calc
+    have : (-g) ≫ d = 0 := calc
       (-g) ≫ d = (biprod.inr ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inr_desc]
       _ = biprod.inr ≫ u := by rw [Category.assoc, hd]
       _ = 0 := biprod.inr_desc _ _
@@ -717,8 +715,7 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
     obtain ⟨d, hd⟩ := KernelFork.IsLimit.lift' this u hu
     dsimp at d
     dsimp at hd
-    have : d ≫ f = 0;
-    calc
+    have : d ≫ f = 0 := calc
       d ≫ f = d ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [biprod.lift_fst]
       _ = u ≫ biprod.fst := by rw [← Category.assoc, hd]
       _ = 0 := biprod.lift_fst _ _
@@ -741,8 +738,7 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
     obtain ⟨d, hd⟩ := KernelFork.IsLimit.lift' this u hu
     dsimp at d
     dsimp at hd
-    have : d ≫ (-g) = 0;
-    calc
+    have : d ≫ (-g) = 0 := calc
       d ≫ (-g) = d ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [biprod.lift_snd]
       _ = biprod.lift e (0 : R ⟶ Z) ≫ biprod.snd := by rw [← Category.assoc, hd]
       _ = 0 := biprod.lift_snd _ _

• depends on: #5966

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

@@ -2,11 +2,6 @@
 Copyright (c) 2020 Markus Himmel. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel, Johan Commelin, Scott Morrison
-
-! This file was ported from Lean 3 source module category_theory.abelian.basic
-! leanprover-community/mathlib commit a5ff45a1c92c278b03b52459a620cfd9c49ebc80
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.CategoryTheory.Limits.Constructions.Pullbacks
 import Mathlib.CategoryTheory.Preadditive.Biproducts
@@ -14,6 +9,8 @@ import Mathlib.CategoryTheory.Limits.Shapes.Images
 import Mathlib.CategoryTheory.Limits.Constructions.LimitsOfProductsAndEqualizers
 import Mathlib.CategoryTheory.Abelian.NonPreadditive
 
+#align_import category_theory.abelian.basic from "leanprover-community/mathlib"@"a5ff45a1c92c278b03b52459a620cfd9c49ebc80"
+
 /-!
 # Abelian categories
 

Grepping for [^ .:{-] [^ :] and reviewing the results. Once I started I couldn't stop. :-)

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

@@ -642,7 +642,7 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
     have : d = 0 := (cancel_epi f).1 (by simpa)
     -- ...or, in other words, e = 0.
     calc
-      e = biprod.inr ≫ biprod.desc (0 : X ⟶  R) e := by rw [biprod.inr_desc]
+      e = biprod.inr ≫ biprod.desc (0 : X ⟶ R) e := by rw [biprod.inr_desc]
       _ = biprod.inr ≫ biprod.desc f (-g) ≫ d := by rw [← hd]
       _ = biprod.inr ≫ biprod.desc f (-g) ≫ 0 := by rw [this]
       _ = (biprod.inr ≫ biprod.desc f (-g)) ≫ 0 := by rw [← Category.assoc]
@@ -676,7 +676,7 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
     have : d = 0 := (cancel_epi (-g)).1 (by simpa)
     -- ...or, in other words, e = 0.
     calc
-      e = biprod.inl ≫ biprod.desc e (0 : Y ⟶  R) := by rw [biprod.inl_desc]
+      e = biprod.inl ≫ biprod.desc e (0 : Y ⟶ R) := by rw [biprod.inl_desc]
       _ = biprod.inl ≫ biprod.desc f (-g) ≫ d := by rw [← hd]
       _ = biprod.inl ≫ biprod.desc f (-g) ≫ 0 := by rw [this]
       _ = (biprod.inl ≫ biprod.desc f (-g)) ≫ 0 := by rw [← Category.assoc]
@@ -727,7 +727,7 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       _ = 0 := biprod.lift_fst _ _
     have : d = 0 := (cancel_mono f).1 (by simpa)
     calc
-      e = biprod.lift (0 : R ⟶  Y) e ≫ biprod.snd := by rw [biprod.lift_snd]
+      e = biprod.lift (0 : R ⟶ Y) e ≫ biprod.snd := by rw [biprod.lift_snd]
       _ = (d ≫ biprod.lift f (-g)) ≫ biprod.snd := by rw [← hd]
       _ = (0 ≫ biprod.lift f (-g)) ≫ biprod.snd := by rw [this]
       _ = 0 ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [Category.assoc]
@@ -747,11 +747,11 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
     have : d ≫ (-g) = 0;
     calc
       d ≫ (-g) = d ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [biprod.lift_snd]
-      _ = biprod.lift e (0 : R ⟶  Z) ≫ biprod.snd := by rw [← Category.assoc, hd]
+      _ = biprod.lift e (0 : R ⟶ Z) ≫ biprod.snd := by rw [← Category.assoc, hd]
       _ = 0 := biprod.lift_snd _ _
     have : d = 0 := (cancel_mono (-g)).1 (by simpa)
     calc
-      e = biprod.lift e (0 : R ⟶  Z) ≫ biprod.fst := by rw [biprod.lift_fst]
+      e = biprod.lift e (0 : R ⟶ Z) ≫ biprod.fst := by rw [biprod.lift_fst]
       _ = (d ≫ biprod.lift f (-g)) ≫ biprod.fst := by rw [← hd]
       _ = (0 ≫ biprod.lift f (-g)) ≫ biprod.fst := by rw [this]
       _ = 0 ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [Category.assoc]

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

@@ -26,7 +26,7 @@ and if every monomorphism and epimorphism is normal.
 
 It should be noted that if we also assume coproducts, then preadditivity is
 actually a consequence of the other properties, as we show in
-`non_preadditive_abelian.lean`. However, this fact is of little practical
+`NonPreadditiveAbelian.lean`. However, this fact is of little practical
 relevance, since essentially all interesting abelian categories come with a
 preadditive structure. In this way, by requiring preadditivity, we allow the
 user to pass in the "native" preadditive structure for the specific category they are
@@ -34,7 +34,7 @@ working with.
 
 ## Main definitions
 
-* `Abelian` is the type class indicating that a category is abelian. It extends `preadditive`.
+* `Abelian` is the type class indicating that a category is abelian. It extends `Preadditive`.
 * `Abelian.image f` is `kernel (cokernel.π f)`, and
 * `Abelian.coimage f` is `cokernel (kernel.ι f)`.
 
@@ -42,7 +42,7 @@ working with.
 
 * In an abelian category, mono + epi = iso.
 * If `f : X ⟶ Y`, then the map `factorThruImage f : X ⟶ image f` is an epimorphism, and the map
-  `factor_thru_coimage f : coimage f ⟶ Y` is a monomorphism.
+  `factorThruCoimage f : coimage f ⟶ Y` is a monomorphism.
 * Factoring through the image and coimage is a strong epi-mono factorisation. This means that
   * every abelian category has images. We provide the isomorphism
     `imageIsoImage : abelian.image f ≅ limits.image f`.
@@ -74,7 +74,7 @@ convention:
 * If the statement of a theorem involves limits, the existence of these limits should be made an
   explicit typeclass parameter.
 * If a limit only appears in a proof, but not in the statement of a theorem, the limit should not
-  be a typeclass parameter, but instead be created using `abelian.has_pullbacks` or a similar
+  be a typeclass parameter, but instead be created using `Abelian.hasPullbacks` or a similar
   definition.
 
 ## References
@@ -150,7 +150,8 @@ def imageMonoFactorisation {X Y : C} (f : X ⟶ Y) : MonoFactorisation f where
 
 theorem imageMonoFactorisation_e' {X Y : C} (f : X ⟶ Y) :
     (imageMonoFactorisation f).e = cokernel.π _ ≫ Abelian.coimageImageComparison f := by
-  apply equalizer.hom_ext
+  dsimp
+  ext
   simp only [Abelian.coimageImageComparison, imageMonoFactorisation_e, Category.assoc,
     cokernel.π_desc_assoc]
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.image_mono_factorisation_e' CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageMonoFactorisation_e'
@@ -166,7 +167,7 @@ def imageFactorisation {X Y : C} (f : X ⟶ Y) [IsIso (Abelian.coimageImageCompa
         rw [imageMonoFactorisation_m]
         simp only [Category.assoc]
         rw [IsIso.inv_comp_eq]
-        apply coequalizer.hom_ext
+        ext
         simp }
 #align category_theory.abelian.of_coimage_image_comparison_is_iso.image_factorisation CategoryTheory.Abelian.OfCoimageImageComparisonIsIso.imageFactorisation
 
@@ -401,7 +402,7 @@ instance : IsIso (coimageImageComparison f) := by
     IsIso.of_iso
       (IsImage.isoExt (coimageStrongEpiMonoFactorisation f).toMonoIsImage
         (imageStrongEpiMonoFactorisation f).toMonoIsImage)
-  apply coequalizer.hom_ext; apply equalizer.hom_ext
+  ext
   change _ = _ ≫ (imageStrongEpiMonoFactorisation f).m
   simp [-imageStrongEpiMonoFactorisation_m]
 
@@ -420,7 +421,7 @@ abbrev coimageIsoImage' : Abelian.coimage f ≅ image f :=
 theorem coimageIsoImage'_hom :
     (coimageIsoImage' f).hom =
       cokernel.desc _ (factorThruImage f) (by simp [← cancel_mono (Limits.image.ι f)]) := by
-  apply coequalizer.hom_ext
+  ext
   simp only [← cancel_mono (Limits.image.ι f), IsImage.isoExt_hom, cokernel.π_desc,
     Category.assoc, IsImage.lift_ι, coimageStrongEpiMonoFactorisation_m,
     Limits.image.fac]
@@ -445,7 +446,7 @@ theorem imageIsoImage_hom_comp_image_ι : (imageIsoImage f).hom ≫ Limits.image
 theorem imageIsoImage_inv :
     (imageIsoImage f).inv =
       kernel.lift _ (Limits.image.ι f) (by simp [← cancel_epi (factorThruImage f)]) := by
-  apply image.ext; apply equalizer.hom_ext
+  ext
   rw [IsImage.isoExt_inv, image.isImage_lift, Limits.image.fac_lift,
     imageStrongEpiMonoFactorisation_e, Category.assoc, kernel.lift_ι, equalizer_as_kernel,
     kernel.lift_ι, Limits.image.fac]

These are all doc fixes

@@ -543,7 +543,7 @@ namespace PullbackToBiproductIsKernel
 variable [Limits.HasPullbacks C] {X Y Z : C} (f : X ⟶ Z) (g : Y ⟶ Z)
 
 /-! This section contains a slightly technical result about pullbacks and biproducts.
-    We will need it in the proof that the pullback of an epimorphism is an epimorpism. -/
+    We will need it in the proof that the pullback of an epimorphism is an epimorphism. -/
 
 
 /-- The canonical map `pullback f g ⟶ X ⊞ Y` -/

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".

@@ -651,10 +651,8 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
 /-- In an abelian category, the pullback of an epimorphism is an epimorphism. -/
 instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X) :=
   -- It will suffice to consider some morphism e : X ⟶ R such that
-    -- pullback.fst ≫ e = 0 and show that e = 0.
-    epi_of_cancel_zero
-    _ fun {R} e h =>
-    by
+  -- pullback.fst ≫ e = 0 and show that e = 0.
+  epi_of_cancel_zero _ fun {R} e h => by
     -- Consider the morphism u := (e, 0) : X ⊞ Y ⟶ R.
     let u := biprod.desc e (0 : Y ⟶ R)
     -- The composite pullback f g ⟶ X ⊞ Y ⟶ R is zero by assumption.

• data.mv_polynomial.basic, data.mv_polynomial.funext: leanprover-community/mathlib#18839
• category_theory.limits.preserves.finite, category_theory.preadditive.projective: leanprover-community/mathlib#18890
• category_theory.abelian.basic, category_theory.abelian.opposite: leanprover-community/mathlib#18740
• topology.category.Top.limits.basic: leanprover-community/mathlib#18871. Note that this does not show a useful diff on the dashboard pages as file splits aren't tracked well by git.

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

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Markus Himmel, Johan Commelin, Scott Morrison
 
 ! This file was ported from Lean 3 source module category_theory.abelian.basic
-! leanprover-community/mathlib commit 8c75ef3517d4106e89fe524e6281d0b0545f47fc
+! leanprover-community/mathlib commit a5ff45a1c92c278b03b52459a620cfd9c49ebc80
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -268,12 +268,12 @@ namespace CategoryTheory.Abelian
 
 variable {C : Type u} [Category.{v} C] [Abelian C]
 
-/-- An abelian category has finite biproducts. -/
--- Porting note: we would like this to be an instance, and indeed it worked in mathlib3
--- however it triggers https://github.com/leanprover/lean4/issues/2055
--- during the simpNF linter, so for now we turn it on locally in this file.
--- This will likely cause problems in downstream ports, unfortunately.
+-- Porting note: the below porting note is from mathlib3!
+-- Porting note: this should be an instance,
+-- but triggers https://github.com/leanprover/lean4/issues/2055
+-- We set it as a local instance instead.
 -- instance (priority := 100)
+/-- An abelian category has finite biproducts. -/
 theorem hasFiniteBiproducts : HasFiniteBiproducts C :=
   Limits.HasFiniteBiproducts.of_hasFiniteProducts
 #align category_theory.abelian.has_finite_biproducts CategoryTheory.Abelian.hasFiniteBiproducts

This PR fixes two things:

• Most align statements for definitions and theorems and instances that are separated by two newlines from the relevant declaration (s/\n\n#align/\n#align). This is often seen in the mathport output after ending calc blocks.
• All remaining more-than-one-line #align statements. (This was needed for a script I wrote for #3630.)

@@ -637,7 +637,6 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
       f ≫ d = (biprod.inl ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inl_desc]
       _ = biprod.inl ≫ u := by rw [Category.assoc, hd]
       _ = 0 := biprod.inl_desc _ _
-
     -- But f is an epimorphism, so d = 0...
     have : d = 0 := (cancel_epi f).1 (by simpa)
     -- ...or, in other words, e = 0.
@@ -647,7 +646,6 @@ instance epi_pullback_of_epi_f [Epi f] : Epi (pullback.snd : pullback f g ⟶ Y)
       _ = biprod.inr ≫ biprod.desc f (-g) ≫ 0 := by rw [this]
       _ = (biprod.inr ≫ biprod.desc f (-g)) ≫ 0 := by rw [← Category.assoc]
       _ = 0 := HasZeroMorphisms.comp_zero _ _
-
 #align category_theory.abelian.epi_pullback_of_epi_f CategoryTheory.Abelian.epi_pullback_of_epi_f
 
 /-- In an abelian category, the pullback of an epimorphism is an epimorphism. -/
@@ -675,7 +673,6 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
       (-g) ≫ d = (biprod.inr ≫ biprod.desc f (-g)) ≫ d := by rw [biprod.inr_desc]
       _ = biprod.inr ≫ u := by rw [Category.assoc, hd]
       _ = 0 := biprod.inr_desc _ _
-
     -- But g is an epimorphism, thus so is -g, so d = 0...
     have : d = 0 := (cancel_epi (-g)).1 (by simpa)
     -- ...or, in other words, e = 0.
@@ -685,7 +682,6 @@ instance epi_pullback_of_epi_g [Epi g] : Epi (pullback.fst : pullback f g ⟶ X)
       _ = biprod.inl ≫ biprod.desc f (-g) ≫ 0 := by rw [this]
       _ = (biprod.inl ≫ biprod.desc f (-g)) ≫ 0 := by rw [← Category.assoc]
       _ = 0 := HasZeroMorphisms.comp_zero _ _
-
 #align category_theory.abelian.epi_pullback_of_epi_g CategoryTheory.Abelian.epi_pullback_of_epi_g
 
 theorem epi_snd_of_isLimit [Epi f] {s : PullbackCone f g} (hs : IsLimit s) : Epi s.snd := by
@@ -730,7 +726,6 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       d ≫ f = d ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [biprod.lift_fst]
       _ = u ≫ biprod.fst := by rw [← Category.assoc, hd]
       _ = 0 := biprod.lift_fst _ _
-
     have : d = 0 := (cancel_mono f).1 (by simpa)
     calc
       e = biprod.lift (0 : R ⟶  Y) e ≫ biprod.snd := by rw [biprod.lift_snd]
@@ -738,7 +733,6 @@ instance mono_pushout_of_mono_f [Mono f] : Mono (pushout.inr : Z ⟶ pushout f g
       _ = (0 ≫ biprod.lift f (-g)) ≫ biprod.snd := by rw [this]
       _ = 0 ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [Category.assoc]
       _ = 0 := zero_comp
-
 #align category_theory.abelian.mono_pushout_of_mono_f CategoryTheory.Abelian.mono_pushout_of_mono_f
 
 instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g) :=
@@ -756,7 +750,6 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
       d ≫ (-g) = d ≫ biprod.lift f (-g) ≫ biprod.snd := by rw [biprod.lift_snd]
       _ = biprod.lift e (0 : R ⟶  Z) ≫ biprod.snd := by rw [← Category.assoc, hd]
       _ = 0 := biprod.lift_snd _ _
-
     have : d = 0 := (cancel_mono (-g)).1 (by simpa)
     calc
       e = biprod.lift e (0 : R ⟶  Z) ≫ biprod.fst := by rw [biprod.lift_fst]
@@ -764,7 +757,6 @@ instance mono_pushout_of_mono_g [Mono g] : Mono (pushout.inl : Y ⟶ pushout f g
       _ = (0 ≫ biprod.lift f (-g)) ≫ biprod.fst := by rw [this]
       _ = 0 ≫ biprod.lift f (-g) ≫ biprod.fst := by rw [Category.assoc]
       _ = 0 := zero_comp
-
 #align category_theory.abelian.mono_pushout_of_mono_g CategoryTheory.Abelian.mono_pushout_of_mono_g
 
 theorem mono_inr_of_isColimit [Mono f] {s : PushoutCocone f g} (hs : IsColimit s) : Mono s.inr := by

See discussion at https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/mathport.20drops.20priorities.20in.20.60attribute.20.5Binstance.5D.60. mathport has been dropping the priorities on instances when using the attribute command.

This PR adds back all the priorities, except for local attribute, and instances involving coercions, which I didn't want to mess with.

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

@@ -115,9 +115,8 @@ class Abelian extends Preadditive C, NormalMonoCategory C, NormalEpiCategory C w
   [has_cokernels : HasCokernels C]
 #align category_theory.abelian CategoryTheory.Abelian
 
-attribute [instance] Abelian.has_finite_products
-
-attribute [instance] Abelian.has_kernels Abelian.has_cokernels
+attribute [instance 100] Abelian.has_finite_products
+attribute [instance 90] Abelian.has_kernels Abelian.has_cokernels
 
 end CategoryTheory
 

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