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

Goal state before:
pp: case refine_1
C : Type u
inst✝⁶ : Category.{v, u} C
FC : C → C → Type u_1
CC : C → Type v
inst✝⁵ : (X Y : C) → FunLike (FC X Y) (CC X) (CC Y)
inst✝⁴ : ConcreteCategory C FC
inst✝³ : HasForget₂ C Ab
inst✝² : Abelian C
inst✝¹ : (forget₂ C Ab).Additive
inst✝ : (forget₂ C Ab).PreservesHomology
ι : Type u_2
c : ComplexShape ι
S : ShortComplex (HomologicalComplex C c)
hS : S.ShortExact
i j : ι
hij : c.Rel i j
x₃ : ↑((forget₂ C Ab).obj (S.X₃.X i))
hx₃ : (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.d i j))) x₃ = 0
x₂ : ↑((forget₂ C Ab).obj (S.X₂.X i))
hx₂ : (ConcreteCategory.hom ((forget₂ C Ab).map (S.g.f i))) x₂ = x₃
x₁ : ↑((forget₂ C Ab).obj (S.X₁.X j))
hx₁ :
  (ConcreteCategory.hom ((forget₂ C Ab).map (S.f.f j))) x₁ = (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₂.d i j))) x₂
k : ι
hk : c.next j = k
⊢ (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.pOpcycles i)))
      ((ConcreteCategory.hom ((forget₂ C Ab).map (S.g.f i))) x₂) =
    (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.pOpcycles i)))
      ((ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.iCycles i))) (S.X₃.cyclesMk x₃ j ⋯ hx₃))

Tactic:
hx₂,

Goal state after:
case refine_1
C : Type u
inst✝⁶ : Category.{v, u} C
FC : C → C → Type u_1
CC : C → Type v
inst✝⁵ : (X Y : C) → FunLike (FC X Y) (CC X) (CC Y)
inst✝⁴ : ConcreteCategory C FC
inst✝³ : HasForget₂ C Ab
inst✝² : Abelian C
inst✝¹ : (forget₂ C Ab).Additive
inst✝ : (forget₂ C Ab).PreservesHomology
ι : Type u_2
c : ComplexShape ι
S : ShortComplex (HomologicalComplex C c)
hS : S.ShortExact
i j : ι
hij : c.Rel i j
x₃ : ↑((forget₂ C Ab).obj (S.X₃.X i))
hx₃ : (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.d i j))) x₃ = 0
x₂ : ↑((forget₂ C Ab).obj (S.X₂.X i))
hx₂ : (ConcreteCategory.hom ((forget₂ C Ab).map (S.g.f i))) x₂ = x₃
x₁ : ↑((forget₂ C Ab).obj (S.X₁.X j))
hx₁ :
  (ConcreteCategory.hom ((forget₂ C Ab).map (S.f.f j))) x₁ = (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₂.d i j))) x₂
k : ι
hk : c.next j = k
⊢ (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.pOpcycles i))) x₃ =
    (ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.pOpcycles i)))
      ((ConcreteCategory.hom ((forget₂ C Ab).map (S.X₃.iCycles i))) (S.X₃.cyclesMk x₃ j ⋯ hx₃))
Module: Mathlib.Algebra.Homology.Embedding.ExtendHomotopy

Goal state before:
pp: case pos
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 : HasZeroObject C
inst✝¹ : Preadditive C
K L : HomologicalComplex C c
f g : K ⟶ L
h : Homotopy f g
e : c.Embedding c'
inst✝ : e.IsRelIff
i' j' : ι'
hij' : ¬c'.Rel j' i'
hi' : ∃ i, e.f i = i'
⊢ extend.hom e h.hom i' j' = 0

pp: case neg
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 : HasZeroObject C
inst✝¹ : Preadditive C
K L : HomologicalComplex C c
f g : K ⟶ L
h : Homotopy f g
e : c.Embedding c'
inst✝ : e.IsRelIff
i' j' : ι'
hij' : ¬c'.Rel j' i'
hi' : ¬∃ i, e.f i = i'
⊢ extend.hom e h.hom i' j' = 0

Tactic:
· obtain ⟨i, rfl⟩ := hi'
      by_cases hj' : ∃ j, e.f j = j'
      · obtain ⟨j, rfl⟩ := hj'
        rw [extend.hom_eq _ _ rfl rfl, h.zero _ _ (by rwa [← e.rel_iff]),
          zero_comp, comp_zero]
      · exact extend.hom_eq_zero₂ _ _ _ _ (by tauto)

Goal state after:
case neg
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 : HasZeroObject C
inst✝¹ : Preadditive C
K L : HomologicalComplex C c
f g : K ⟶ L
h : Homotopy f g
e : c.Embedding c'
inst✝ : e.IsRelIff
i' j' : ι'
hij' : ¬c'.Rel j' i'
hi' : ¬∃ i, e.f i = i'
⊢ extend.hom e h.hom i' j' = 0
Module: Mathlib.Algebra.Homology.Embedding.ExtendHomotopy

Goal state before:
pp: case pos
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 : HasZeroObject C
inst✝¹ : Preadditive C
K L : HomologicalComplex C c
f g : K ⟶ L
e : c.Embedding c'
inst✝ : e.IsRelIff
h : Homotopy (extendMap f e) (extendMap g e)
j' : ι'
i : ι
hj' : ∃ j, e.f j = j'
⊢ (h.ofExtend.extend e).hom (e.f i) j' = h.hom (e.f i) j'

Tactic:
obtain ⟨j, rfl⟩ := hj'
      simp [extend_hom_eq _ e rfl rfl, ofExtend_hom]

Goal state after:
Module: Mathlib.CategoryTheory.LiftingProperties.Limits

Goal state before:
pp: C : Type u_1
inst✝³ : Category.{v_1, u_1} C
X✝ Y✝ Z W : C
f✝ : X✝ ⟶ Y✝
s : X✝ ⟶ Z
g : Z ⟶ W
t✝ : Y✝ ⟶ W
J : Type u_2
A B : J → C
inst✝² : HasProduct A
inst✝¹ : HasProduct B
f : (j : J) → A j ⟶ B j
X Y : C
p : X ⟶ Y
inst✝ : ∀ (j : J), HasLiftingProperty p (f j)
t : X ⟶ ∏ᶜ A
b : Y ⟶ ∏ᶜ B
sq : CommSq t p (Limits.Pi.map f) b
j : J
⊢ (t ≫ Pi.π A j) ≫ f j = p ≫ b ≫ Pi.π B j

Tactic:
rw [← Category.assoc, ← sq.w]; simp

Goal state after:
Module: Mathlib.AlgebraicTopology.ModelCategory.CategoryWithCofibrations

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
X Y : C
f : X ⟶ Y
inst✝¹ : CategoryWithFibrations C
inst✝ : CategoryWithWeakEquivalences C
⊢ trivialFibrations C f ↔ Fibration f ∧ WeakEquivalence f

Tactic:
rw [fibration_iff, weakEquivalence_iff]
  rfl

Goal state after:
Module: Mathlib.AlgebraicTopology.ModelCategory.CategoryWithCofibrations

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
X Y : C
f : X ⟶ Y
inst✝¹ : CategoryWithWeakEquivalences C
inst✝ : WeakEquivalence f
⊢ WeakEquivalence f.op

Tactic:
by
  rwa [weakEquivalences_op_iff]

Goal state after:
Module: Mathlib.AlgebraicTopology.ModelCategory.CategoryWithCofibrations

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
X✝ Y✝ : C
f✝ : X✝ ⟶ Y✝
inst✝¹ : CategoryWithWeakEquivalences C
X Y : Cᵒᵖ
f : X ⟶ Y
inst✝ : WeakEquivalence f
⊢ WeakEquivalence f.unop

Tactic:
by
  rwa [weakEquivalences_unop_iff]

Goal state after:
Module: Mathlib.AlgebraicTopology.ModelCategory.Instances

Goal state before:
pp: C : Type u
inst✝⁶ : Category.{v, u} C
inst✝⁵ : CategoryWithWeakEquivalences C
inst✝⁴ : CategoryWithCofibrations C
inst✝³ : CategoryWithFibrations C
X₁ X₂ Y₁ Y₂ : C
f₁ : X₁ ⟶ Y₁
f₂ : X₂ ⟶ Y₂
inst✝² : (cofibrations C).IsWeakFactorizationSystem (trivialFibrations C)
h₁ : Cofibration f₁
h₂ : Cofibration f₂
inst✝¹ : HasBinaryCoproduct X₁ X₂
inst✝ : HasBinaryCoproduct Y₁ Y₂
⊢ Cofibration (coprod.map f₁ f₂)

Tactic:
rw [cofibration_iff] at h₁ h₂ ⊢
  apply MorphismProperty.colimMap
  rintro (_ | _) <;> assumption

Goal state after:
Module: Mathlib.AlgebraicTopology.ModelCategory.Basic

Goal state before:
pp: C : Type u
inst✝⁸ : Category.{v, u} C
inst✝⁷ : CategoryWithFibrations C
inst✝⁶ : CategoryWithCofibrations C
inst✝⁵ : CategoryWithWeakEquivalences C
inst✝⁴ : HasFiniteLimits C
inst✝³ : HasFiniteColimits C
inst✝² : (weakEquivalences C).HasTwoOutOfThreeProperty
inst✝¹ : (cofibrations C).IsWeakFactorizationSystem (trivialFibrations C)
inst✝ : (trivialCofibrations C).IsWeakFactorizationSystem (fibrations C)
⊢ (cofibrations C).IsStableUnderRetracts

Tactic:
by
    rw [← llp_eq_of_wfs (cofibrations C) (trivialFibrations C)]
    infer_instance

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
⊢ t.IsLE X n₀ ↔ IsZero ((t.truncGE n₁).obj X)

Tactic:
rw [t.isLE_iff_isIso_truncLTι_app n₀ n₁ h 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
⊢ IsIso ((t.truncLTι n₁).app X) ↔ IsZero ((t.truncGE n₁).obj X)
Module: Mathlib.CategoryTheory.Triangulated.TStructure.TruncLTGE

Goal state before:
pp: C : Type u
inst✝⁶ : Category.{v, u} C
inst✝⁵ : Preadditive C
inst✝⁴ : HasZeroObject C
inst✝³ : HasShift C ℤ
inst✝² : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝¹ : Pretriangulated C
t : TStructure C
n₀ n₁ : ℤ
h : n₀ + 1 = n₁
X : C
inst✝ : t.IsLE X n₀
⊢ IsZero ((t.truncGE n₁).obj X)

Tactic:
rw [← t.isLE_iff_isZero_truncGE_obj _ _ h X]
  infer_instance

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
Y Z : C
g : Y ⟶ Z
n₀ n₁ : ℤ
hn : n₀ + 1 = n₁
⊢ IsIso ((t.truncGE n₁).map g) ↔
    ∃ X f h, ∃ (_ : Triangle.mk f (g ≫ (t.truncGEπ n₁).app Z) h ∈ distinguishedTriangles), t.IsLE X n₀

Tactic:
refine ⟨fun hf ↦ ?_, fun ⟨X, f, h, mem, _⟩ ↦ ?_⟩

Goal state after:
case refine_1
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
Y Z : C
g : Y ⟶ Z
n₀ n₁ : ℤ
hn : n₀ + 1 = n₁
hf : IsIso ((t.truncGE n₁).map g)
⊢ ∃ X f h, ∃ (_ : Triangle.mk f (g ≫ (t.truncGEπ n₁).app Z) h ∈ distinguishedTriangles), t.IsLE X n₀

case refine_2
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
Y Z : C
g : Y ⟶ Z
n₀ n₁ : ℤ
hn : n₀ + 1 = n₁
x✝ : ∃ X f h, ∃ (_ : Triangle.mk f (g ≫ (t.truncGEπ n₁).app Z) h ∈ distinguishedTriangles), t.IsLE X n₀
X : C
f : X ⟶ Y
h : (t.truncGE n₁).obj Z ⟶ (shiftFunctor C 1).obj X
mem : Triangle.mk f (g ≫ (t.truncGEπ n₁).app Z) h ∈ distinguishedTriangles
h✝ : t.IsLE X n₀
⊢ IsIso ((t.truncGE n₁).map g)
Module: Mathlib.Algebra.Homology.ModelCategory.Injective

Goal state before:
pp: C : Type u_1
inst✝³ : Category.{u_2, u_1} C
inst✝² : Abelian C
A B X Y : Plus C
i : A ⟶ B
p : X ⟶ Y
inst✝¹ : Mono i
inst✝ : Fibration p
hip : WeakEquivalence i ∨ WeakEquivalence p
t : A ⟶ X
b : B ⟶ Y
sq : CommSq t i p b
⊢ sq.HasLift

Tactic:
obtain ⟨A, hA⟩ := A

Goal state after:
C : Type u_1
inst✝³ : Category.{u_2, u_1} C
inst✝² : Abelian C
B X Y : Plus C
p : X ⟶ Y
inst✝¹ : Fibration p
b : B ⟶ Y
A : CochainComplex C ℤ
hA : CochainComplex.plus C A
i : { obj := A, property := hA } ⟶ B
inst✝ : Mono i
hip : WeakEquivalence i ∨ WeakEquivalence p
t : { obj := A, property := hA } ⟶ X
sq : CommSq t i p b
⊢ sq.HasLift
Module: Mathlib.Algebra.Homology.ModelCategory.Injective

Goal state before:
pp: 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)
hip : QuasiIso i ∨ QuasiIso p
sq : CommSq t i p b
sq' : ∀ (n : ℤ), CommSq (t.f n) (i.f n) (p.f n) (b.f n)
n : ℤ
⊢ ⋯.HasLift

Tactic:
have := (hp n).hasLiftingProperty (i.f n)

Goal state after:
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)
hip : QuasiIso i ∨ QuasiIso p
sq : CommSq t i p b
sq' : ∀ (n : ℤ), CommSq (t.f n) (i.f n) (p.f n) (b.f n)
n : ℤ
this : HasLiftingProperty (i.f n) (p.f n)
⊢ ⋯.HasLift
Module: Mathlib.CategoryTheory.MorphismProperty.Quotient

Goal state before:
pp: case trans
C : Type u_1
inst✝³ : Category.{v_1, u_1} C
W : MorphismProperty C
homRel : HomRel C
inst✝² : HomRel.IsStableUnderPrecomp homRel
inst✝¹ : HomRel.IsStableUnderPostcomp homRel
inst✝ : W.HasQuotient homRel
X Y : C
f g x✝ y✝ z✝ : X ⟶ Y
a✝¹ : Relation.EqvGen homRel x✝ y✝
a✝ : Relation.EqvGen homRel y✝ z✝
h₁ : W x✝ ↔ W y✝
h₂ : W y✝ ↔ W z✝
⊢ W x✝ ↔ W z✝

Tactic:
| trans _ _ _ _ _ h₁ h₂ =>

Goal state after:
Module: Mathlib.AlgebraicTopology.ModelCategory.Homotopy

Goal state before:
pp: C : Type u
inst✝⁶ : Category.{v, u} C
inst✝⁵ : ModelCategory C
X Y : C
inst✝⁴ : IsCofibrant X
inst✝³ : IsCofibrant Y
inst✝² : IsFibrant X
inst✝¹ : IsFibrant Y
f : X ⟶ Y
inst✝ : WeakEquivalence f
g : Y ⟶ X
hg : mk (f ≫ g) = mk (𝟙 X)
⊢ RightHomotopyRel (f ≫ g) (𝟙 X)

Tactic:
rwa [← mk_eq_mk_iff]

Goal state after:
Module: Mathlib.CategoryTheory.Localization.DerivabilityStructure.Constructor

Goal state before:
pp: C₁ : Type u_1
C₂ : Type u_2
inst✝⁶ : Category.{v_1, u_1} C₁
inst✝⁵ : Category.{v_2, u_2} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
inst✝⁴ : ∀ (X₂ : C₂), IsConnected (Φ.RightResolution X₂)
inst✝³ : Φ.arrow.HasRightResolutions
inst✝² : W₂.ContainsIdentities
D : Type u_3
inst✝¹ : Category.{v_3, u_3} D
L : C₂ ⥤ D
inst✝ : L.IsLocalization W₂
X₂ : C₂
X₃ : D
y : L.obj X₂ ⟶ X₃
w : TwoSquare Φ.functor (Φ.functor ⋙ L) L (𝟭 D) :=
  TwoSquare.mk Φ.functor (Φ.functor ⋙ L) L (𝟭 D) (Φ.functor ⋙ L).rightUnitor.inv
this✝ : Nonempty (w.CostructuredArrowDownwards y)
this : ∀ (X : w.CostructuredArrowDownwards y), ∃ Y, Zigzag X ((fromRightResolution Φ L y).obj Y)
X X' : (TwoSquare.mk Φ.functor (Φ.functor ⋙ L) L (𝟭 D) (Φ.functor ⋙ L).rightUnitor.inv).CostructuredArrowDownwards y
Y : Φ.RightResolution X₂
hX : Zigzag X ((fromRightResolution Φ L y).obj Y)
Y' : Φ.RightResolution X₂
hX' : Zigzag X' ((fromRightResolution Φ L y).obj Y')
⊢ Zigzag X X'

Tactic:
exact hX.trans ((zigzag_obj_of_zigzag _ (isPreconnected_zigzag Y Y')).trans hX'.symm)

Goal state after:
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
X₂ X₂' : C₂
e : X₂ ≅ X₂'
⊢ (w.structuredArrowDownwards X₂).Initial ↔ (w.structuredArrowDownwards X₂').Initial

Tactic:
by
  rw [Functor.initial_iff_comp_equivalence _ (StructuredArrow.mapIso (R.mapIso e)).functor,
    Functor.initial_iff_equivalence_comp (StructuredArrow.mapIso e).functor]
  exact Functor.initial_natIso_iff
    (NatIso.ofComponents (fun _ ↦ StructuredArrow.isoMk (Iso.refl _)))

Goal state after:
Module: Mathlib.CategoryTheory.Localization.DerivabilityStructure.Basic

Goal state before:
pp: C₁ : Type u₁
C₂ : Type u₂
inst✝¹ : Category.{v₁, u₁} C₁
inst✝ : Category.{v₂, u₂} C₂
W₁ : MorphismProperty C₁
W₂ : MorphismProperty C₂
Φ : LocalizerMorphism W₁ W₂
⊢ Φ.IsLeftDerivabilityStructure ↔ Φ.op.IsRightDerivabilityStructure

Tactic:
let F := Φ.localizedFunctor W₁.Q W₂.Q
  let e : Φ.functor ⋙ W₂.Q ≅ W₁.Q ⋙ F := (Φ.catCommSq W₁.Q W₂.Q).iso
  let e' : Φ.functor.op ⋙ W₂.Q.op ≅ W₁.Q.op ⋙ F.op := NatIso.op e.symm
  have eq : TwoSquare.GuitartExact e'.hom ↔ TwoSquare.GuitartExact e.inv :=
    TwoSquare.guitartExact_op_iff _
  constructor
  · rintro ⟨_, _⟩
    rwa [Φ.op.isRightDerivabilityStructure_iff _ _ _ e', eq]
  · intro
    have : Φ.HasLeftResolutions := by
      rw [hasLeftResolutions_iff_op]
      infer_instance
    refine ⟨inferInstance, ?_⟩
    rw [← eq]
    exact Φ.op.guitartExact_of_isRightDerivabilityStructure' _ _ _ e'

Goal state after:
Module: Mathlib.CategoryTheory.Localization.StructuredArrow

Goal state before:
pp: C : Type u_1
inst✝ : Category.{v_1, u_1} C
W : MorphismProperty C
X : C
P : StructuredArrow (W.Q.obj X) W.Q → Prop
hP₀ : P (StructuredArrow.mk (𝟙 (W.Q.obj X)))
hP₁ :
  ∀ ⦃Y₁ Y₂ : C⦄ (f : Y₁ ⟶ Y₂) (φ : W.Q.obj X ⟶ W.Q.obj Y₁),
    P (StructuredArrow.mk φ) → P (StructuredArrow.mk (φ ≫ W.Q.map f))
hP₂ :
  ∀ ⦃Y₁ Y₂ : C⦄ (w : Y₁ ⟶ Y₂) (hw : W w) (φ : W.Q.obj X ⟶ W.Q.obj Y₂),
    P (StructuredArrow.mk φ) → P (StructuredArrow.mk (φ ≫ (isoOfHom W.Q W w hw).inv))
g : StructuredArrow (W.Q.obj X) W.Q
X₀ : Paths (LocQuiver W) := { obj := X }
Y₀ : Paths (LocQuiver W)
f : X₀ ⟶ Y₀
⊢ P (StructuredArrow.mk ((Quotient.functor (relations W)).map f))

Tactic:
induction f with

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

Goal state before:
pp: C₁ : Type u₁
C₂ : Type u₂
C₃ : Type u₃
C₄ : Type u₄
D : Type u₅
inst✝⁶ : Category.{v₁, u₁} C₁
inst✝⁵ : Category.{v₂, u₂} C₂
inst✝⁴ : Category.{v₃, u₃} C₃
inst✝³ : Category.{v₄, u₄} C₄
inst✝² : Category.{v₅, u₅} D
T : C₁ ⥤ C₂
L : C₁ ⥤ C₃
R : C₂ ⥤ C₄
B : C₃ ⥤ C₄
w : TwoSquare T L R B
inst✝¹ : ∀ (F : C₁ ⥤ D), L.HasLeftKanExtension F
inst✝ : ∀ (F : C₂ ⥤ D), R.HasLeftKanExtension F
F : C₂ ⥤ D
⊢ IsIso (w.lanBaseChange.app F) ↔
    (StructuredArrow.right ((LeftExtension.mk (R.lan.obj F) (R.lanUnit.app F)).compTwoSquare w)).IsLeftKanExtension
      (StructuredArrow.hom ((LeftExtension.mk (R.lan.obj F) (R.lanUnit.app F)).compTwoSquare w))

Tactic:
lanBaseChange_app,

Goal state after:
C₁ : Type u₁
C₂ : Type u₂
C₃ : Type u₃
C₄ : Type u₄
D : Type u₅
inst✝⁶ : Category.{v₁, u₁} C₁
inst✝⁵ : Category.{v₂, u₂} C₂
inst✝⁴ : Category.{v₃, u₃} C₃
inst✝³ : Category.{v₄, u₄} C₄
inst✝² : Category.{v₅, u₅} D
T : C₁ ⥤ C₂
L : C₁ ⥤ C₃
R : C₂ ⥤ C₄
B : C₃ ⥤ C₄
w : TwoSquare T L R B
inst✝¹ : ∀ (F : C₁ ⥤ D), L.HasLeftKanExtension F
inst✝ : ∀ (F : C₂ ⥤ D), R.HasLeftKanExtension F
F : C₂ ⥤ D
⊢ IsIso
      (((L.lanAdjunction D).homEquiv (((whiskeringLeft C₁ C₂ D).obj T).obj F)
            ((R.lan ⋙ (whiskeringLeft C₃ C₄ D).obj B).obj F)).symm
        (StructuredArrow.hom ((LeftExtension.mk (R.lan.obj F) (R.lanUnit.app F)).compTwoSquare w))) ↔
    (StructuredArrow.right ((LeftExtension.mk (R.lan.obj F) (R.lanUnit.app F)).compTwoSquare w)).IsLeftKanExtension
      (StructuredArrow.hom ((LeftExtension.mk (R.lan.obj F) (R.lanUnit.app F)).compTwoSquare w))
Module: Mathlib.CategoryTheory.GuitartExact.KanExtension

Goal state before:
pp: C₁ : Type u₁
C₂ : Type u₂
C₃ : Type u₃
C₄ : Type u₄
D : Type u₅
inst✝⁸ : Category.{v₁, u₁} C₁
inst✝⁷ : Category.{v₂, u₂} C₂
inst✝⁶ : Category.{v₃, u₃} C₃
inst✝⁵ : Category.{v₄, u₄} C₄
inst✝⁴ : Category.{v₅, u₅} D
T : C₁ ⥤ C₂
L : C₁ ⥤ C₃
R : C₂ ⥤ C₄
B : C₃ ⥤ C₄
w : TwoSquare T L R B
inst✝³ : ∀ (F : C₁ ⥤ D), L.HasLeftKanExtension F
inst✝² : ∀ (F : C₂ ⥤ D), R.HasLeftKanExtension F
F : C₂ ⥤ D
inst✝¹ : R.HasPointwiseLeftKanExtension F
inst✝ : w.GuitartExact
⊢ IsIso (w.lanBaseChange.app F)

Tactic:
isIso_lanBaseChange_app_iff

Goal state after:
C₁ : Type u₁
C₂ : Type u₂
C₃ : Type u₃
C₄ : Type u₄
D : Type u₅
inst✝⁸ : Category.{v₁, u₁} C₁
inst✝⁷ : Category.{v₂, u₂} C₂
inst✝⁶ : Category.{v₃, u₃} C₃
inst✝⁵ : Category.{v₄, u₄} C₄
inst✝⁴ : Category.{v₅, u₅} D
T : C₁ ⥤ C₂
L : C₁ ⥤ C₃
R : C₂ ⥤ C₄
B : C₃ ⥤ C₄
w : TwoSquare T L R B
inst✝³ : ∀ (F : C₁ ⥤ D), L.HasLeftKanExtension F
inst✝² : ∀ (F : C₂ ⥤ D), R.HasLeftKanExtension F
F : C₂ ⥤ D
inst✝¹ : R.HasPointwiseLeftKanExtension F
inst✝ : w.GuitartExact
⊢ (StructuredArrow.right ((LeftExtension.mk (R.lan.obj F) (R.lanUnit.app F)).compTwoSquare w)).IsLeftKanExtension
    (StructuredArrow.hom ((LeftExtension.mk (R.lan.obj F) (R.lanUnit.app F)).compTwoSquare w))
Module: Mathlib.Algebra.Homology.ExactSequenceFour

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{?u.4, u_1} C
inst✝ : HasZeroMorphisms C
n : ℕ
S : ComposableArrows C (n + 3)
hS : S.IsComplex
k : ℕ
hk : k ≤ n
cc : CokernelCofork (S.map' k (k + 1) ⋯ ⋯)
kf : KernelFork (S.map' (k + 2) (k + 3) ⋯ ⋯)
hcc : IsColimit cc
hkf : IsLimit kf
⊢ (S.map' k (k + 1) ⋯ ⋯ ≫ hkf.lift (KernelFork.ofι (S.map' (k + 1) (k + 1 + 1) ⋯ ⋯) ⋯)) ≫ Fork.ι kf = 0 ≫ Fork.ι kf

Tactic:
simpa using hS.zero k

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

Goal state before:
pp: T : Type u_1
inst✝² : Category.{v_1, u_1} T
V : Type u_2
inst✝¹ : Category.{v_2, u_2} V
inst✝ : HasZeroMorphisms V
ι : Type u_3
c : ComplexShape ι
C : HomologicalComplex (T ⥤ V) c
t : T
i j : ι
h : ¬c.Rel i j
⊢ (C.d i j).app t = 0

Tactic:
have := C.shape _ _ h

Goal state after:
T : Type u_1
inst✝² : Category.{v_1, u_1} T
V : Type u_2
inst✝¹ : Category.{v_2, u_2} V
inst✝ : HasZeroMorphisms V
ι : Type u_3
c : ComplexShape ι
C : HomologicalComplex (T ⥤ V) c
t : T
i j : ι
h : ¬c.Rel i j
this : C.d i j = 0
⊢ (C.d i j).app t = 0
Module: Mathlib.Algebra.Homology.Functor

Goal state before:
pp: T : Type u_1
inst✝² : Category.{v_1, u_1} T
V : Type u_2
inst✝¹ : Category.{v_2, u_2} V
inst✝ : HasZeroMorphisms V
ι : Type u_3
c : ComplexShape ι
C : HomologicalComplex (T ⥤ V) c
t : T
i j k : ι
x✝¹ : c.Rel i j
x✝ : c.Rel j k
⊢ (C.d i j).app t ≫ (C.d j k).app t = 0

Tactic:
have := C.d_comp_d i j k
        rw [NatTrans.ext_iff, funext_iff] at this
        exact this t

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

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Preadditive C
inst✝ : HasZeroObject C
X : C
K : CochainComplex C ℤ
p n : ℤ
α : Cocycle ((singleFunctor C p).obj X) K n
q : ℤ
h : p + n = q
q' : ℤ
hq' : q + 1 = q'
f : X ⟶ K.X q
hf : Cochain.fromSingleMk f h = ↑α
hα : δ n (n + 1) ↑α = 0
⊢ ∃ f, ∃ (hf : f ≫ K.d q q' = 0), fromSingleMk f h q' hq' hf = α

Tactic:
rw [← hf, Cochain.δ_fromSingleMk _ _ _ q' (by lia)] at hα

Goal state after:
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Preadditive C
inst✝ : HasZeroObject C
X : C
K : CochainComplex C ℤ
p n : ℤ
α : Cocycle ((singleFunctor C p).obj X) K n
q : ℤ
h : p + n = q
q' : ℤ
hq' : q + 1 = q'
f : X ⟶ K.X q
hf : Cochain.fromSingleMk f h = ↑α
hα : Cochain.fromSingleMk (f ≫ K.d q q') ⋯ = 0
⊢ ∃ f, ∃ (hf : f ≫ K.d q q' = 0), fromSingleMk f h q' hq' hf = α
Module: Mathlib.CategoryTheory.Abelian.Projective.Resolution

Goal state before:
pp: C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Abelian C
inst✝ : HasProjectiveResolutions C
X Y : C
f : X ⟶ Y
P : ProjectiveResolution X
Q : ProjectiveResolution Y
φ : P.complex ⟶ Q.complex
comm : φ.f 0 ≫ Q.π.f 0 = P.π.f 0 ≫ f
⊢ (projectiveResolutions C).map f ≫ Q.iso.hom = P.iso.hom ≫ (HomotopyCategory.quotient C (ComplexShape.down ℕ)).map φ

Tactic:
← cancel_epi (P.iso).inv,

Goal state after:
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : Abelian C
inst✝ : HasProjectiveResolutions C
X Y : C
f : X ⟶ Y
P : ProjectiveResolution X
Q : ProjectiveResolution Y
φ : P.complex ⟶ Q.complex
comm : φ.f 0 ≫ Q.π.f 0 = P.π.f 0 ≫ f
⊢ P.iso.inv ≫ (projectiveResolutions C).map f ≫ Q.iso.hom =
    P.iso.inv ≫ P.iso.hom ≫ (HomotopyCategory.quotient C (ComplexShape.down ℕ)).map φ