mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Algebra.Homology.TotalComplex

Goal state before:
pp: C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Preadditive C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂ C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst✝² : TotalComplexShape c₁ c₂ c₁₂
inst✝¹ : DecidableEq I₁₂
inst✝ : K.HasTotal c₁₂
i₁ : I₁
i₂ i₂' : I₂
h : c₂.Rel i₂ i₂'
i₁₂ : I₁₂
h' : c₁.π c₂ c₁₂ (i₁, i₂') = i₁₂
⊢ c₁.ε₂ c₂ c₁₂ (i₁, i₂) • (K.X i₁).d i₂ i₂' ≫ K.toGradedObject.ιMapObjOrZero (c₁.π c₂ c₁₂) (i₁, i₂') i₁₂ =
    c₁.ε₂ c₂ c₁₂ (i₁, i₂) • (K.X i₁).d i₂ i₂' ≫ K.toGradedObject.ιMapObj (c₁.π c₂ c₁₂) (i₁, i₂') i₁₂ h'

Tactic:
K.toGradedObject.ιMapObjOrZero_eq

Goal state after:
C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Preadditive C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂ C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst✝² : TotalComplexShape c₁ c₂ c₁₂
inst✝¹ : DecidableEq I₁₂
inst✝ : K.HasTotal c₁₂
i₁ : I₁
i₂ i₂' : I₂
h : c₂.Rel i₂ i₂'
i₁₂ : I₁₂
h' : c₁.π c₂ c₁₂ (i₁, i₂') = i₁₂
⊢ c₁.ε₂ c₂ c₁₂ (i₁, i₂) • (K.X i₁).d i₂ i₂' ≫ K.toGradedObject.ιMapObj (c₁.π c₂ c₁₂) (i₁, i₂') i₁₂ ?h =
    c₁.ε₂ c₂ c₁₂ (i₁, i₂) • (K.X i₁).d i₂ i₂' ≫ K.toGradedObject.ιMapObj (c₁.π c₂ c₁₂) (i₁, i₂') i₁₂ h'

case h
C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Preadditive C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂ C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst✝² : TotalComplexShape c₁ c₂ c₁₂
inst✝¹ : DecidableEq I₁₂
inst✝ : K.HasTotal c₁₂
i₁ : I₁
i₂ i₂' : I₂
h : c₂.Rel i₂ i₂'
i₁₂ : I₁₂
h' : c₁.π c₂ c₁₂ (i₁, i₂') = i₁₂
⊢ c₁.π c₂ c₁₂ (i₁, i₂') = i₁₂
Module: Mathlib.Algebra.Homology.TotalComplexShift

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Preadditive C
K L : HomologicalComplex₂ C (up ℤ) (up ℤ)
f : K ⟶ L
x y : ℤ
inst✝ : K.HasTotal (up ℤ)
n n' : ℤ
x✝ : (up ℤ).Rel n n'
⊢ (K.totalShift₁XIso x n (n + x) ⋯).hom ≫ ((shiftFunctor (HomologicalComplex C (up ℤ)) x).obj (K.total (up ℤ))).d n n' =
    (((shiftFunctor₁ C x).obj K).total (up ℤ)).d n n' ≫ (K.totalShift₁XIso x n' (n' + x) ⋯).hom

Tactic:
by
      dsimp
      simp only [total_d, Preadditive.add_comp, Preadditive.comp_add, smul_add,
        Linear.comp_units_smul, K.D₁_totalShift₁XIso_hom x n n' _ _ rfl rfl,
        K.D₂_totalShift₁XIso_hom x n n' _ _ rfl rfl]

Goal state after:
Module: Mathlib.Algebra.Homology.DerivedCategory.SmallShiftedHom

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Abelian C
K L : CochainComplex C ℤ
n : ℤ
inst✝ : HasSmallLocalizedShiftedHom (HomologicalComplex.quasiIso C (ComplexShape.up ℤ)) ℤ K L
x : CohomologyClass K L n
this : HasDerivedCategory C := HasDerivedCategory.standard C
y₁ y₂ : Cocycle K L n
h : y₁ ≈ y₂
⊢ DerivedCategory.Q.map (Cocycle.equivHomShift.symm y₁) ≫ (Functor.commShiftIso DerivedCategory.Q n).hom.app L =
    DerivedCategory.Q.map (Cocycle.equivHomShift.symm y₂) ≫ (Functor.commShiftIso DerivedCategory.Q n).hom.app L

Tactic:
cancel_mono,

Goal state after:
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Abelian C
K L : CochainComplex C ℤ
n : ℤ
inst✝ : HasSmallLocalizedShiftedHom (HomologicalComplex.quasiIso C (ComplexShape.up ℤ)) ℤ K L
x : CohomologyClass K L n
this : HasDerivedCategory C := HasDerivedCategory.standard C
y₁ y₂ : Cocycle K L n
h : y₁ ≈ y₂
⊢ DerivedCategory.Q.map (Cocycle.equivHomShift.symm y₁) = DerivedCategory.Q.map (Cocycle.equivHomShift.symm y₂)
Module: Mathlib.CategoryTheory.Triangulated.Orthogonal

Goal state before:
pp: case refine_3
C : Type u
inst✝⁶ : Category.{v, u} C
P : ObjectProperty C
inst✝⁵ : HasZeroObject C
inst✝⁴ : HasShift C ℤ
inst✝³ : Preadditive C
inst✝² : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝¹ : Pretriangulated C
inst✝ : P.IsTriangulated
Y : C
hY : P.rightOrthogonal Y
X₁ X₂ : C
f : X₁ ⟶ X₂
x✝ : P.trW f
X₃ : C
g : X₂ ⟶ X₃
h : X₃ ⟶ (shiftFunctor C 1).obj X₁
hT : Triangle.mk f g h ∈ distinguishedTriangles
hX₃ : P X₃
α : X₁ ⟶ Y
⊢ ∃ a, (fun g ↦ f ≫ g) a = α

Tactic:
obtain ⟨β, rfl⟩ := Triangle.yoneda_exact₂ _ (inv_rot_of_distTriang _ hT)
      α (hY _ (P.le_shift _ _ hX₃))

Goal state after:
case refine_3
C : Type u
inst✝⁶ : Category.{v, u} C
P : ObjectProperty C
inst✝⁵ : HasZeroObject C
inst✝⁴ : HasShift C ℤ
inst✝³ : Preadditive C
inst✝² : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝¹ : Pretriangulated C
inst✝ : P.IsTriangulated
Y : C
hY : P.rightOrthogonal Y
X₁ X₂ : C
f : X₁ ⟶ X₂
x✝ : P.trW f
X₃ : C
g : X₂ ⟶ X₃
h : X₃ ⟶ (shiftFunctor C 1).obj X₁
hT : Triangle.mk f g h ∈ distinguishedTriangles
hX₃ : P X₃
β : (Triangle.mk f g h).invRotate.obj₃ ⟶ Y
⊢ ∃ a, (fun g ↦ f ≫ g) a = (Triangle.mk f g h).invRotate.mor₂ ≫ β
Module: Mathlib.CategoryTheory.Triangulated.TStructure.Basic

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
inst✝⁴ : Preadditive C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝ : Pretriangulated C
t : TStructure C
A : C
n₀ n₁ : ℤ
h✝ : n₀ + 1 = n₁
X Y : C
hX : t.le 0 X
hY : t.ge 1 Y
f : X ⟶ (shiftFunctor C n₀).obj A
g : (shiftFunctor C n₀).obj A ⟶ Y
h : Y ⟶ (shiftFunctor C 1).obj X
mem : Triangle.mk f g h ∈ distinguishedTriangles
T : Triangle C := (Triangle.shiftFunctor C (-n₀)).obj (Triangle.mk f g h)
e : ((shiftEquiv C n₀).functor ⋙ (shiftEquiv C n₀).inverse).obj A ≅ (𝟭 C).obj A := (shiftEquiv C n₀).unitIso.symm.app A
hT' : Triangle.mk (T.mor₁ ≫ e.hom) (e.inv ≫ T.mor₂) T.mor₃ ∈ distinguishedTriangles
⊢ ∃ X Y, ∃ (_ : t.le n₀ X) (_ : t.ge n₁ Y), ∃ f g h, Triangle.mk f g h ∈ distinguishedTriangles

Tactic:
exact ⟨_, _, t.le_shift _ _ _ (neg_add_cancel n₀) _ hX,
    t.ge_shift _ _ _ (by lia) _ hY, _, _, _, hT'⟩

Goal state after:
Module: Mathlib.Algebra.Homology.HomotopyCategory.KInjective

Goal state before:
pp: C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Abelian C
K L : CochainComplex C ℤ
f : K ⟶ L
α : Cochain K L (-1)
n : ℤ
hα : (δ (-1) 0 α).EqUpTo (Cochain.ofHom f) n
hK : (HomologicalComplex.sc' K n (n + 1) (n + 2)).Exact
inst✝ : Injective (L.X (n + 1))
u : K.X (n + 1) ⟶ L.X (n + 1) :=
  f.f (n + 1) - α.v (n + 1) n ⋯ ≫ L.d n (n + 1) - K.d (n + 1) (n + 2) ≫ α.v (n + 2) (n + 1) ⋯
hu : K.d n (n + 1) ≫ u = 0
β : K.X (n + 2) ⟶ L.X (n + 1)
hβ : K.d (n + 1) (n + 2) ≫ β = u
p : ℤ
hp : p ≤ n + 1
hpq : p + 0 = p
⊢ (δ (-1) 0 (α + Cochain.single β (-1))).v p p hpq = (Cochain.ofHom f).v p p hpq

Tactic:
obtain hp | rfl := hp.lt_or_eq

Goal state after:
case inl
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Abelian C
K L : CochainComplex C ℤ
f : K ⟶ L
α : Cochain K L (-1)
n : ℤ
hα : (δ (-1) 0 α).EqUpTo (Cochain.ofHom f) n
hK : (HomologicalComplex.sc' K n (n + 1) (n + 2)).Exact
inst✝ : Injective (L.X (n + 1))
u : K.X (n + 1) ⟶ L.X (n + 1) :=
  f.f (n + 1) - α.v (n + 1) n ⋯ ≫ L.d n (n + 1) - K.d (n + 1) (n + 2) ≫ α.v (n + 2) (n + 1) ⋯
hu : K.d n (n + 1) ≫ u = 0
β : K.X (n + 2) ⟶ L.X (n + 1)
hβ : K.d (n + 1) (n + 2) ≫ β = u
p : ℤ
hp✝ : p ≤ n + 1
hpq : p + 0 = p
hp : p < n + 1
⊢ (δ (-1) 0 (α + Cochain.single β (-1))).v p p hpq = (Cochain.ofHom f).v p p hpq

case inr
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Abelian C
K L : CochainComplex C ℤ
f : K ⟶ L
α : Cochain K L (-1)
n : ℤ
hα : (δ (-1) 0 α).EqUpTo (Cochain.ofHom f) n
hK : (HomologicalComplex.sc' K n (n + 1) (n + 2)).Exact
inst✝ : Injective (L.X (n + 1))
u : K.X (n + 1) ⟶ L.X (n + 1) :=
  f.f (n + 1) - α.v (n + 1) n ⋯ ≫ L.d n (n + 1) - K.d (n + 1) (n + 2) ≫ α.v (n + 2) (n + 1) ⋯
hu : K.d n (n + 1) ≫ u = 0
β : K.X (n + 2) ⟶ L.X (n + 1)
hβ : K.d (n + 1) (n + 2) ≫ β = u
hp : n + 1 ≤ n + 1
hpq : n + 1 + 0 = n + 1
⊢ (δ (-1) 0 (α + Cochain.single β (-1))).v (n + 1) (n + 1) hpq = (Cochain.ofHom f).v (n + 1) (n + 1) hpq
Module: Mathlib.CategoryTheory.LiftingProperties.Limits

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
X Y Z W : C
f : X ⟶ Y
s : X ⟶ Z
g : Z ⟶ W
t : Y ⟶ W
h : IsPullback s f g t
X' Y' : C
f' : X' ⟶ Y'
inst✝ : HasLiftingProperty f' g
u : X' ⟶ X
v : Y' ⟶ Y
sq : CommSq u f' f v
w : (u ≫ s) ≫ g = f' ≫ v ≫ t
⊢ ⋯.lift ≫ g = v ≫ t

Tactic:
by rw [CommSq.fac_right]

Goal state after:
Module: Mathlib.Algebra.Homology.BifunctorAssociator

Goal state before:
pp: case neg
C₁ : Type u_1
C₂ : Type u_2
C₂₃ : Type u_4
C₃ : Type u_5
C₄ : Type u_6
inst✝²³ : Category.{v_1, u_1} C₁
inst✝²² : Category.{v_2, u_2} C₂
inst✝²¹ : Category.{v_3, u_5} C₃
inst✝²⁰ : Category.{v_4, u_6} C₄
inst✝¹⁹ : Category.{v_6, u_4} C₂₃
inst✝¹⁸ : HasZeroMorphisms C₁
inst✝¹⁷ : HasZeroMorphisms C₂
inst✝¹⁶ : HasZeroMorphisms C₃
inst✝¹⁵ : Preadditive C₂₃
inst✝¹⁴ : Preadditive C₄
F : C₁ ⥤ C₂₃ ⥤ C₄
G₂₃ : C₂ ⥤ C₃ ⥤ C₂₃
inst✝¹³ : G₂₃.PreservesZeroMorphisms
inst✝¹² : ∀ (X₂ : C₂), (G₂₃.obj X₂).PreservesZeroMorphisms
inst✝¹¹ : F.PreservesZeroMorphisms
inst✝¹⁰ : ∀ (X₁ : C₁), (F.obj X₁).Additive
ι₁ : Type u_7
ι₂ : Type u_8
ι₃ : Type u_9
ι₁₂ : Type u_10
ι₂₃ : Type u_11
ι₄ : Type u_12
inst✝⁹ : DecidableEq ι₄
c₁ : ComplexShape ι₁
c₂ : ComplexShape ι₂
c₃ : ComplexShape ι₃
K₁ : HomologicalComplex C₁ c₁
K₂ : HomologicalComplex C₂ c₂
K₃ : HomologicalComplex C₃ c₃
c₁₂ : ComplexShape ι₁₂
c₂₃ : ComplexShape ι₂₃
c₄ : ComplexShape ι₄
inst✝⁸ : TotalComplexShape c₁ c₂ c₁₂
inst✝⁷ : TotalComplexShape c₁₂ c₃ c₄
inst✝⁶ : TotalComplexShape c₂ c₃ c₂₃
inst✝⁵ : TotalComplexShape c₁ c₂₃ c₄
inst✝⁴ : K₂.HasMapBifunctor K₃ G₂₃ c₂₃
inst✝³ : c₁.Associative c₂ c₃ c₁₂ c₂₃ c₄
inst✝² : DecidableEq ι₂₃
inst✝¹ : K₁.HasMapBifunctor (K₂.mapBifunctor K₃ G₂₃ c₂₃) F c₄
inst✝ : HasGoodTrifunctor₂₃Obj F G₂₃ K₁ K₂ K₃ c₁₂ c₂₃ c₄
j j' : ι₄
i₁ : ι₁
i₂ : ι₂
i₃ : ι₃
h : c₁.r c₂ c₃ c₁₂ c₄ (i₁, i₂, i₃) = j
i₂₃ : ι₂₃ := c₂.π c₃ c₂₃ (i₂, i₃)
h₁ : c₂₃.Rel i₂₃ (c₂₃.next i₂₃)
h₂ : c₁.π c₂₃ c₄ (i₁, c₂₃.next i₂₃) = j'
h₃ : ¬c₃.Rel i₃ (c₃.next i₃)
⊢ c₁.ε₂ c₂₃ c₄ (i₁, i₂₃) •
      (F.obj (K₁.X i₁)).map (mapBifunctor.d₂ K₂ K₃ G₂₃ c₂₃ i₂ i₃ (c₂₃.next i₂₃)) ≫
        K₁.ιMapBifunctor (K₂.mapBifunctor K₃ G₂₃ c₂₃) F c₄ i₁ (c₂₃.next i₂₃) j' h₂ =
    d₃ F G₂₃ K₁ K₂ K₃ c₁₂ c₂₃ c₄ i₁ i₂ i₃ j'

Tactic:
· rw [d₃_eq_zero _ _ _ _ _ _ _ _ _ _ _ _ h₃,
            mapBifunctor.d₂_eq_zero _ _ _ _ _ _ _ h₃,
            Functor.map_zero, zero_comp, smul_zero]

Goal state after:
Module: Mathlib.CategoryTheory.Triangulated.Opposite.Triangulated

Goal state before:
pp: C : Type u_1
inst✝⁶ : Category.{v_1, u_1} C
inst✝⁵ : HasShift C ℤ
inst✝⁴ : HasZeroObject C
inst✝³ : Preadditive C
inst✝² : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝¹ : Pretriangulated C
inst✝ : IsTriangulated C
X₁ X₂ X₃ Z₁₂ Z₂₃ Z₁₃ : Cᵒᵖ
u₁₂ : X₁ ⟶ X₂
u₂₃ : X₂ ⟶ X₃
u₁₃ : X₁ ⟶ X₃
⊢ ∀ (comm : u₁₂ ≫ u₂₃ = u₁₃) {v₁₂ : X₂ ⟶ Z₁₂} {w₁₂ : Z₁₂ ⟶ (shiftFunctor Cᵒᵖ 1).obj X₁}
    (h₁₂ : Triangle.mk u₁₂ v₁₂ w₁₂ ∈ Pretriangulated.distinguishedTriangles) {v₂₃ : X₃ ⟶ Z₂₃}
    {w₂₃ : Z₂₃ ⟶ (shiftFunctor Cᵒᵖ 1).obj X₂} (h₂₃ : Triangle.mk u₂₃ v₂₃ w₂₃ ∈ Pretriangulated.distinguishedTriangles)
    {v₁₃ : X₃ ⟶ Z₁₃} {w₁₃ : Z₁₃ ⟶ (shiftFunctor Cᵒᵖ 1).obj X₁}
    (h₁₃ : Triangle.mk u₁₃ v₁₃ w₁₃ ∈ Pretriangulated.distinguishedTriangles),
    Nonempty (Triangulated.Octahedron comm h₁₂ h₂₃ h₁₃)

Tactic:
comm

Goal state after:
C : Type u_1
inst✝⁶ : Category.{v_1, u_1} C
inst✝⁵ : HasShift C ℤ
inst✝⁴ : HasZeroObject C
inst✝³ : Preadditive C
inst✝² : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝¹ : Pretriangulated C
inst✝ : IsTriangulated C
X₁ X₂ X₃ Z₁₂ Z₂₃ Z₁₃ : Cᵒᵖ
u₁₂ : X₁ ⟶ X₂
u₂₃ : X₂ ⟶ X₃
u₁₃ : X₁ ⟶ X₃
comm : u₁₂ ≫ u₂₃ = u₁₃
⊢ ∀ {v₁₂ : X₂ ⟶ Z₁₂} {w₁₂ : Z₁₂ ⟶ (shiftFunctor Cᵒᵖ 1).obj X₁}
    (h₁₂ : Triangle.mk u₁₂ v₁₂ w₁₂ ∈ Pretriangulated.distinguishedTriangles) {v₂₃ : X₃ ⟶ Z₂₃}
    {w₂₃ : Z₂₃ ⟶ (shiftFunctor Cᵒᵖ 1).obj X₂} (h₂₃ : Triangle.mk u₂₃ v₂₃ w₂₃ ∈ Pretriangulated.distinguishedTriangles)
    {v₁₃ : X₃ ⟶ Z₁₃} {w₁₃ : Z₁₃ ⟶ (shiftFunctor Cᵒᵖ 1).obj X₁}
    (h₁₃ : Triangle.mk u₁₃ v₁₃ w₁₃ ∈ Pretriangulated.distinguishedTriangles),
    Nonempty (Triangulated.Octahedron comm h₁₂ h₂₃ h₁₃)
Module: Mathlib.Algebra.Homology.HomotopyCategory.Plus

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁸ : Category.{v_1, u_1} C
inst✝⁷ : Category.{v_2, u_2} D
inst✝⁶ : Preadditive C
inst✝⁵ : Preadditive D
A : Type u_3
inst✝⁴ : Category.{v_3, u_3} A
inst✝³ : Abelian A
F : C ⥤ D
inst✝² : F.Additive
inst✝¹ : F.Full
inst✝ : F.Faithful
X✝ Y✝ : HomotopyCategory.Plus C
f : F.mapHomotopyCategoryPlus.obj X✝ ⟶ F.mapHomotopyCategoryPlus.obj Y✝
⊢ F.mapHomotopyCategoryPlus.map (ObjectProperty.homMk ((F.mapHomotopyCategory (ComplexShape.up ℤ)).preimage f.hom)) = f

Tactic:
ext
      exact (F.mapHomotopyCategory _).map_preimage f.hom

Goal state after:
Module: Mathlib.CategoryTheory.Triangulated.TStructure.TruncLTGE

Goal state before:
pp: C : Type u
inst✝⁵ : Category.{v, u} C
inst✝⁴ : Preadditive C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝ : Pretriangulated C
t : TStructure C
n : ℤ
x✝³ x✝² : C
x✝¹ x✝ : x✝³ ⟶ x✝²
⊢ (t.truncLT n).map (x✝¹ + x✝) = (t.truncLT n).map x✝¹ + (t.truncLT n).map x✝

Tactic:
dsimp only [truncLT, Functor.comp_map]

Goal state after:
C : Type u
inst✝⁵ : Category.{v, u} C
inst✝⁴ : Preadditive C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝ : Pretriangulated C
t : TStructure C
n : ℤ
x✝³ x✝² : C
x✝¹ x✝ : x✝³ ⟶ x✝²
⊢ Triangle.π₁.map ((TruncAux.triangleFunctor t n).map (x✝¹ + x✝)) =
    Triangle.π₁.map ((TruncAux.triangleFunctor t n).map x✝¹) + Triangle.π₁.map ((TruncAux.triangleFunctor t n).map x✝)
Module: Mathlib.CategoryTheory.Abelian.EpiWithInjectiveKernel

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Abelian C
X Y Z : C
g₁ : X ⟶ Y
g₂ : Y ⟶ Z
hg₁ :
  ∃ I,
    ∃ (_ : Injective I),
      ∃ f, ∃ (w : f ≫ g₁ = 0), Nonempty { X₁ := I, X₂ := X, X₃ := Y, f := f, g := g₁, zero := w }.Splitting
hg₂ :
  ∃ I,
    ∃ (_ : Injective I),
      ∃ f, ∃ (w : f ≫ g₂ = 0), Nonempty { X₁ := I, X₂ := Y, X₃ := Z, f := f, g := g₂, zero := w }.Splitting
⊢ ∃ I,
    ∃ (_ : Injective I),
      ∃ f, ∃ (w : f ≫ g₁ ≫ g₂ = 0), Nonempty { X₁ := I, X₂ := X, X₃ := Z, f := f, g := g₁ ≫ g₂, zero := w }.Splitting

Tactic:
obtain ⟨I₁, _, f₁, w₁, ⟨σ₁⟩⟩ := hg₁

Goal state after:
C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Abelian C
X Y Z : C
g₁ : X ⟶ Y
g₂ : Y ⟶ Z
hg₂ :
  ∃ I,
    ∃ (_ : Injective I),
      ∃ f, ∃ (w : f ≫ g₂ = 0), Nonempty { X₁ := I, X₂ := Y, X₃ := Z, f := f, g := g₂, zero := w }.Splitting
I₁ : C
w✝ : Injective I₁
f₁ : I₁ ⟶ X
w₁ : f₁ ≫ g₁ = 0
σ₁ : { X₁ := I₁, X₂ := X, X₃ := Y, f := f₁, g := g₁, zero := w₁ }.Splitting
⊢ ∃ I,
    ∃ (_ : Injective I),
      ∃ f, ∃ (w : f ≫ g₁ ≫ g₂ = 0), Nonempty { X₁ := I, X₂ := X, X₃ := Z, f := f, g := g₁ ≫ g₂, zero := w }.Splitting
Module: Mathlib.CategoryTheory.Functor.OfSequence

Goal state before:
pp: C : Type u_1
inst✝ : Category.{v_1, u_1} C
i : ℕ
⊢ ∀ {X : ℕ → C} (f : (n : ℕ) → X n ⟶ X (n + 1)), map f i i ⋯ = 𝟙 (X i)

Tactic:
induction i with

Goal state after:
Module: Mathlib.CategoryTheory.Functor.OfSequence

Goal state before:
pp: C : Type u_1
inst✝ : Category.{v_1, u_1} C
i : ℕ
⊢ ∀ {X : ℕ → C} (f : (n : ℕ) → X n ⟶ X (n + 1)), map f i (i + 1) ⋯ = f i

Tactic:
induction i with

Goal state after:
Module: Mathlib.CategoryTheory.Triangulated.TStructure.TruncLTGE

Goal state before:
pp: C : Type u
inst✝⁵ : Category.{v, u} C
inst✝⁴ : Preadditive C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝ : Pretriangulated C
t : TStructure C
n₀ n₁ : ℤ
h : n₀ + 1 = n₁
X : C
hX : ∀ (Y : C) (f : Y ⟶ X), t.IsLE Y n₀ → f = 0
⊢ t.IsGE X n₁

Tactic:
t.isGE_iff_isZero_truncLT_obj n₁ X,

Goal state after:
C : Type u
inst✝⁵ : Category.{v, u} C
inst✝⁴ : Preadditive C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝ : Pretriangulated C
t : TStructure C
n₀ n₁ : ℤ
h : n₀ + 1 = n₁
X : C
hX : ∀ (Y : C) (f : Y ⟶ X), t.IsLE Y n₀ → f = 0
⊢ IsZero ((t.truncLT n₁).obj X)
Module: Mathlib.CategoryTheory.Functor.OfSequence

Goal state before:
pp: case succ
C : Type u_1
inst✝ : Category.{v_1, u_1} C
i : ℕ
hi :
  ∀ {X : ℕ → C} (f : (n : ℕ) → X n ⟶ X (n + 1)) (j k : ℕ) (hij : i ≤ j) (hjk : j ≤ k),
    map f i k ⋯ = map f i j hij ≫ map f j k hjk
X : ℕ → C
f : (n : ℕ) → X n ⟶ X (n + 1)
j k : ℕ
hij : i + 1 ≤ j
hjk : j ≤ k
⊢ map f (i + 1) k ⋯ = map f (i + 1) j hij ≫ map f j k hjk

Tactic:
| succ i hi =>

Goal state after:
Module: Mathlib.Algebra.Homology.ModelCategory.Injective

Goal state before:
pp: case inr
C : Type u_1
inst✝³ : Category.{u_2, u_1} C
inst✝² : Abelian C
A : CochainComplex C ℤ
hA : CochainComplex.plus C A
B : CochainComplex C ℤ
hB : CochainComplex.plus C B
X : CochainComplex C ℤ
hX : CochainComplex.plus C X
Y : CochainComplex C ℤ
hY : CochainComplex.plus C Y
i : A ⟶ B
inst✝¹ : Mono (ObjectProperty.homMk i)
hi : Mono i
p : X ⟶ Y
inst✝ : Fibration (ObjectProperty.homMk p)
hp : degreewiseEpiWithInjectiveKernel p
hip : WeakEquivalence (ObjectProperty.homMk i) ∨ WeakEquivalence (ObjectProperty.homMk p)
t : A ⟶ X
b : B ⟶ Y
sq✝ : CommSq (ObjectProperty.homMk t) (ObjectProperty.homMk i) (ObjectProperty.homMk p) (ObjectProperty.homMk b)
sq : CommSq t i p b
sq' : ∀ (n : ℤ), CommSq (t.f n) (i.f n) (p.f n) (b.f n)
this✝¹ : ∀ (n : ℤ), ⋯.HasLift
β : Cocycle (cokernel i) (kernel p) 1 :=
  Lifting.cocycle₁ sq (fun n ↦ { l := ⋯.lift, fac_left := ⋯, fac_right := ⋯ }) (cokernelIsCokernel i) (kernelIsKernel p)
this✝ : ∀ (n : ℤ), Injective ((kernel p).X n)
this : (kernel p).IsKInjective
h✝ : QuasiIso p
⊢ HomologicalComplex.Acyclic (kernel p)

Tactic:
have := hp.epi

Goal state after:
case inr
C : Type u_1
inst✝³ : Category.{u_2, u_1} C
inst✝² : Abelian C
A : CochainComplex C ℤ
hA : CochainComplex.plus C A
B : CochainComplex C ℤ
hB : CochainComplex.plus C B
X : CochainComplex C ℤ
hX : CochainComplex.plus C X
Y : CochainComplex C ℤ
hY : CochainComplex.plus C Y
i : A ⟶ B
inst✝¹ : Mono (ObjectProperty.homMk i)
hi : Mono i
p : X ⟶ Y
inst✝ : Fibration (ObjectProperty.homMk p)
hp : degreewiseEpiWithInjectiveKernel p
hip : WeakEquivalence (ObjectProperty.homMk i) ∨ WeakEquivalence (ObjectProperty.homMk p)
t : A ⟶ X
b : B ⟶ Y
sq✝ : CommSq (ObjectProperty.homMk t) (ObjectProperty.homMk i) (ObjectProperty.homMk p) (ObjectProperty.homMk b)
sq : CommSq t i p b
sq' : ∀ (n : ℤ), CommSq (t.f n) (i.f n) (p.f n) (b.f n)
this✝² : ∀ (n : ℤ), ⋯.HasLift
β : Cocycle (cokernel i) (kernel p) 1 :=
  Lifting.cocycle₁ sq (fun n ↦ { l := ⋯.lift, fac_left := ⋯, fac_right := ⋯ }) (cokernelIsCokernel i) (kernelIsKernel p)
this✝¹ : ∀ (n : ℤ), Injective ((kernel p).X n)
this✝ : (kernel p).IsKInjective
h✝ : QuasiIso p
this : Epi p
⊢ HomologicalComplex.Acyclic (kernel p)
Module: Mathlib.CategoryTheory.GuitartExact.Basic

Goal state before:
pp: C₁ : Type u₁
C₂ : Type u₂
C₃ : Type u₃
C₄ : Type u₄
inst✝³ : Category.{v₁, u₁} C₁
inst✝² : Category.{v₂, u₂} C₂
inst✝¹ : Category.{v₃, u₃} C₃
inst✝ : Category.{v₄, u₄} C₄
T : C₁ ⥤ C₂
L : C₁ ⥤ C₃
R : C₂ ⥤ C₄
B : C₃ ⥤ C₄
w : TwoSquare T L R B
F : C₁ ⥤ C₂
X₂ : C₁
X₃ : C₂
g : F.obj X₂ ⟶ X₃
Z : Type (max (max u₁ v₂) v₁) := (mk (𝟭 C₁) F F (𝟭 C₂) (𝟙 F)).StructuredArrowRightwards g
X₀ : Z := StructuredArrow.mk (CostructuredArrow.homMk (𝟙 (CostructuredArrow.mk g).left) ⋯)
X : Z
⊢ F.map (StructuredArrow.hom X).left ≫ (StructuredArrow.right X).hom = (StructuredArrow.right X₀).hom

Tactic:
simpa using! CostructuredArrow.w X.hom

Goal state after:
Module: Mathlib.Algebra.Homology.Factorizations.CM5a

Goal state before:
pp: C : Type u_1
inst✝⁵ : Category.{v_1, u_1} C
inst✝⁴ : Abelian C
K L : CochainComplex C ℤ
f : K ⟶ L
inst✝³ : EnoughInjectives C
n : ℤ
inst✝² : K.IsStrictlyGE n
inst✝¹ : L.IsStrictlyGE n
inst✝ : Mono f
⊢ ∃ K', ∃ (_ : K'.IsStrictlyGE n), ∃ ι π, Mono ι ∧ QuasiIso ι ∧ degreewiseEpiWithInjectiveKernel π ∧ ι ≫ π = f

Tactic:
obtain ⟨n, rfl⟩ : ∃ (q : ℤ), n = q + 1 := ⟨n - 1, by simp⟩
  exact ⟨mid f n, inferInstance, ι f n, π f n, inferInstance,
    inferInstance, degreewiseEpiWithInjectiveKernel_π f n, ι_π f n⟩

Goal state after:
Module: Mathlib.CategoryTheory.GuitartExact.HorizontalComposition

Goal state before:
pp: C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
D₁ : Type u_4
D₂ : Type u_5
D₃ : Type u_6
inst✝⁷ : Category.{v_1, u_1} C₁
inst✝⁶ : Category.{v_2, u_2} C₂
inst✝⁵ : Category.{v_3, u_3} C₃
inst✝⁴ : Category.{v_4, u_4} D₁
inst✝³ : Category.{v_5, u_5} D₂
inst✝² : Category.{v_6, u_6} D₃
V₁ : C₁ ⥤ D₁
T₁ : C₁ ⥤ C₂
B₁ : D₁ ⥤ D₂
V₂ : C₂ ⥤ D₂
w : TwoSquare T₁ V₁ V₂ B₁
T₂ : C₂ ⥤ C₃
B₂ : D₂ ⥤ D₃
V₃ : C₃ ⥤ D₃
w' : TwoSquare T₂ V₂ V₃ B₂
T₁₂ : C₁ ⥤ C₃
B₁₂ : D₁ ⥤ D₃
eT : T₁ ⋙ T₂ ≅ T₁₂
eB : B₁ ⋙ B₂ ≅ B₁₂
inst✝¹ : B₁.EssSurj
inst✝ : w.GuitartExact
h : (w.hComp' w' eT eB).GuitartExact
⊢ w'.GuitartExact

Tactic:
dsimp [TwoSquare.hComp'] at h

Goal state after:
C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
D₁ : Type u_4
D₂ : Type u_5
D₃ : Type u_6
inst✝⁷ : Category.{v_1, u_1} C₁
inst✝⁶ : Category.{v_2, u_2} C₂
inst✝⁵ : Category.{v_3, u_3} C₃
inst✝⁴ : Category.{v_4, u_4} D₁
inst✝³ : Category.{v_5, u_5} D₂
inst✝² : Category.{v_6, u_6} D₃
V₁ : C₁ ⥤ D₁
T₁ : C₁ ⥤ C₂
B₁ : D₁ ⥤ D₂
V₂ : C₂ ⥤ D₂
w : TwoSquare T₁ V₁ V₂ B₁
T₂ : C₂ ⥤ C₃
B₂ : D₂ ⥤ D₃
V₃ : C₃ ⥤ D₃
w' : TwoSquare T₂ V₂ V₃ B₂
T₁₂ : C₁ ⥤ C₃
B₁₂ : D₁ ⥤ D₃
eT : T₁ ⋙ T₂ ≅ T₁₂
eB : B₁ ⋙ B₂ ≅ B₁₂
inst✝¹ : B₁.EssSurj
inst✝ : w.GuitartExact
h : ((w ≫ₕ w').whiskerHorizontal eT.inv eB.hom).GuitartExact
⊢ w'.GuitartExact
Module: Mathlib.Algebra.Homology.DerivedCategory.DerivabilityStructureInjectives

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
inst✝ : Abelian C
K L : CochainComplex.Plus (InjectiveObject C)
f : K ⟶ L
⊢ IsIso ((quotient (InjectiveObject C)).map f) ↔
    CochainComplex.Plus.quasiIso C ((InjectiveObject.ι C).mapCochainComplexPlus.map f)

Tactic:
by
  rw [← isIso_iff_of_reflects_iso _ (HomotopyCategory.Plus.ι (InjectiveObject C)),
    ← isIso_iff_of_reflects_iso _ (Functor.mapHomotopyCategory (InjectiveObject.ι C) (.up ℤ))]
  dsimp
  rw [HomologicalComplex.isIso_quotient_map_iff_homotopyEquivalences,
    ← CochainComplex.IsKInjective.quasiIso_iff]
  rfl

Goal state after:
Module: Mathlib.Algebra.Homology.DerivedCategory.DerivabilityStructureInjectives

Goal state before:
pp: C : Type u_1
H : Type u_2
inst✝² : Category.{v_1, u_1} C
inst✝¹ : Abelian C
inst✝ : Category.{v_2, u_2} H
⊢ (quasiIso C).inverseImage (R C).functor = CochainComplex.Plus.quasiIso C

Tactic:
ext; apply quotient_map_mem_quasiIso_iff

Goal state after:
Module: Mathlib.CategoryTheory.DifferentialObject

Goal state before:
pp: S : Type u_1
inst✝³ : AddMonoidWithOne S
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasZeroMorphisms C
inst✝ : HasShift C S
X Y : DifferentialObject S C
f : X.obj ≅ Y.obj
hf : X.d ≫ (shiftFunctor C 1).map f.hom = f.hom ≫ Y.d
⊢ { f := f.inv, comm := ⋯ } ≫ { f := f.hom, comm := hf } = 𝟙 Y

Tactic:
ext1; dsimp; exact f.inv_hom_id

Goal state after:
Module: Mathlib.Algebra.Homology.Double

Goal state before:
pp: case neg
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : HasZeroMorphisms C
inst✝ : HasZeroObject C
X₀ X₁ : C
f : X₀ ⟶ X₁
ι : Type u_2
c : ComplexShape ι
i₁ i j k : ι
hij : c.Rel i j
hjk : c.Rel j k
hi₀₁ : c.Rel i i₁
hj : ¬j = i₁
⊢ ((if hk : i = i ∧ j = i₁ ∧ ¬i = i₁ then eqToHom ⋯ ≫ f ≫ eqToHom ⋯ else 0) ≫
      if hk : j = i ∧ k = i₁ ∧ ¬i = i₁ then eqToHom ⋯ ≫ f ≫ eqToHom ⋯ else 0) =
    0

Tactic:
dif_neg (by tauto),

Goal state after:
case neg
C : Type u_1
inst✝² : Category.{v_1, u_1} C
inst✝¹ : HasZeroMorphisms C
inst✝ : HasZeroObject C
X₀ X₁ : C
f : X₀ ⟶ X₁
ι : Type u_2
c : ComplexShape ι
i₁ i j k : ι
hij : c.Rel i j
hjk : c.Rel j k
hi₀₁ : c.Rel i i₁
hj : ¬j = i₁
⊢ (0 ≫ if hk : j = i ∧ k = i₁ ∧ ¬i = i₁ then eqToHom ⋯ ≫ f ≫ eqToHom ⋯ else 0) = 0
Module: Mathlib.Algebra.Homology.Embedding.StupidTrunc

Goal state before:
pp: ι : Type u_1
ι' : Type u_2
c : ComplexShape ι
c' : ComplexShape ι'
C : Type u_3
inst✝³ : Category.{v_1, u_3} C
inst✝² : HasZeroMorphisms C
inst✝¹ : HasZeroObject C
K L : HomologicalComplex C c'
φ : K ⟶ L
e : c.Embedding c'
inst✝ : e.IsRelIff
i : ι
i' : ι'
hi : e.f i = i'
⊢ (stupidTruncMap φ e).f i' ≫ (L.stupidTruncXIso e hi).hom = (K.stupidTruncXIso e hi).hom ≫ φ.f i'

Tactic:
subst hi
  simp [stupidTruncMap, stupidTruncXIso, extendMap_f _ _ rfl]

Goal state after: