mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.CategoryTheory.Shift.Basic

Goal state before:
pp: C : Type u
A : Type u_1
inst✝³ : Category.{v, u} C
D : Type u_2
inst✝² : Category.{v_1, u_2} D
inst✝¹ : AddMonoid A
inst✝ : HasShift D A
F : C ⥤ D
hF : F.FullyFaithful
s : A → C ⥤ C
i : (i : A) → s i ⋙ F ≅ F ⋙ shiftFunctor D i
a b : A
X : C
⊢ F.map ((add hF s i a b).inv.app X) =
    (i b).hom.app ((s a).obj X) ≫
      (shiftFunctor D b).map ((i a).hom.app X) ≫ (shiftFunctorAdd D a b).inv.app (F.obj X) ≫ (i (a + b)).inv.app X

Tactic:
dsimp [add]
  simp

Goal state after:
Module: Mathlib.RingTheory.Kaehler.Basic

Goal state before:
pp: case a
R : Type u
S : Type v
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : EssFiniteType R S
x : S
⊢ (fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) x ∈
    ↑(Ideal.span ↑(Finset.image (fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) (EssFiniteType.finset R S)))

Tactic:
let I : Ideal (S ⊗[R] S) := Ideal.span
      ((EssFiniteType.finset R S).image (fun s ↦ (1 : S) ⊗ₜ[R] s - s ⊗ₜ[R] (1 : S)))

Goal state after:
case a
R : Type u
S : Type v
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
inst✝ : EssFiniteType R S
x : S
I : Ideal (S ⊗[R] S) := Ideal.span ↑(Finset.image (fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) (EssFiniteType.finset R S))
⊢ (fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) x ∈
    ↑(Ideal.span ↑(Finset.image (fun s ↦ 1 ⊗ₜ[R] s - s ⊗ₜ[R] 1) (EssFiniteType.finset R S)))
Module: Mathlib.CategoryTheory.MorphismProperty.IsInvertedBy

Goal state before:
pp: case mpr
C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
inst✝³ : Category.{v_1, u_1} C₁
inst✝² : Category.{v_2, u_2} C₂
inst✝¹ : Category.{v_3, u_3} C₃
W : MorphismProperty C₁
F : C₁ ⥤ C₂
G : C₂ ⥤ C₃
inst✝ : G.ReflectsIsomorphisms
⊢ W.IsInvertedBy F → W.IsInvertedBy (F ⋙ G)

Tactic:
· intro hF
    exact IsInvertedBy.of_comp W F hF G

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

Goal state before:
pp: ι : Type u_1
V : Type u
inst✝¹ : Category.{v, u} V
inst✝ : Preadditive V
c : ComplexShape ι
C D : HomologicalComplex V c
f : (i j : ι) → C.X i ⟶ D.X j
j j' : ι
w : c.Rel j' j
⊢ (prevD j) f = f j j' ≫ D.d j' j

Tactic:
obtain rfl := c.prev_eq' w
  rfl

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

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : Preadditive C
F G : CochainComplex C ℤ
n : ℤ
z₁ z₂ : Cochain F G n
h : ∀ (p q : ℤ) (hpq : p + n = q), z₁.v p q hpq = z₂.v p q hpq
⊢ z₁ = z₂

Tactic:
funext ⟨p, q, hpq⟩

Goal state after:
C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : Preadditive C
F G : CochainComplex C ℤ
n : ℤ
z₁ z₂ : Cochain F G n
h : ∀ (p q : ℤ) (hpq : p + n = q), z₁.v p q hpq = z₂.v p q hpq
p q : ℤ
hpq : p + n = q
⊢ z₁ { p := p, q := q, hpq := hpq } = z₂ { p := p, q := q, hpq := hpq }
Module: Mathlib.Algebra.Homology.HomotopyCategory.HomComplex

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : Preadditive C
K L : CochainComplex C ℤ
p q : ℤ
f : K.X p ⟶ L.X q
n p' q' : ℤ
hpq' : p' + n = q'
hq' : q' ≠ q
⊢ (single f n).v p' q' hpq' = 0

Tactic:
dsimp [single]
  grind

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

Goal state before:
pp: C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Preadditive C
ι : Type u_2
c : ComplexShape ι
K : HomologicalComplex C c
inst✝² : DecidableRel c.Rel
inst✝¹ : ∀ (i : ι), HasBinaryBiproduct (K.X i) (K.X i)
inst✝ : K.HasCylinder
⊢ ι₀ K ≫ π K = 𝟙 K

Tactic:
by simp [π]

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

Goal state before:
pp: C : Type u_1
inst✝⁴ : Category.{v_1, u_1} C
inst✝³ : Preadditive C
ι : Type u_2
c : ComplexShape ι
K : HomologicalComplex C c
inst✝² : DecidableRel c.Rel
inst✝¹ : ∀ (i : ι), HasBinaryBiproduct (K.X i) (K.X i)
inst✝ : K.HasCylinder
⊢ ι₁ K ≫ π K = 𝟙 K

Tactic:
by simp [π]

Goal state after:
Module: Mathlib.CategoryTheory.Quotient

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
r : HomRel C
D : Type u_2
inst✝ : Category.{v_2, u_2} D
F₁ F₂ : Quotient r ⥤ D
h✝ : functor r ⋙ F₁ = functor r ⋙ F₂
X Y : C
f g : X ⟶ Y
h : r f g
⊢ F₂.map ((functor r).map f) = F₂.map ((functor r).map g)

Tactic:
rw [Quotient.sound r h]

Goal state after:
Module: Mathlib.CategoryTheory.Quotient

Goal state before:
pp: C : Type u_1
inst✝¹ : Category.{v_1, u_1} C
r : HomRel C
D : Type ?u.8
inst✝ : Category.{v_2, ?u.8} D
F✝ : C ⥤ D
H : ∀ (x y : C) (f₁ f₂ : x ⟶ y), r f₁ f₂ → F✝.map f₁ = F✝.map f₂
F G : Quotient r ⥤ D
τ : functor r ⋙ F ⟶ functor r ⋙ G
x✝¹ x✝ : Quotient r
X Y : C
⊢ ∀ (f : { as := X } ⟶ { as := Y }),
    (F.map f ≫
        match { as := Y } with
        | { as := X } => τ.app X) =
      (match { as := X } with
        | { as := X } => τ.app X) ≫
        G.map f

Tactic:
rintro ⟨f⟩
    exact τ.naturality f

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

Goal state before:
pp: R : Type u_1
inst✝³ : Semiring R
ι : Type u_2
V : Type u
inst✝² : Category.{v, u} V
inst✝¹ : Preadditive V
c : ComplexShape ι
inst✝ : HasZeroObject V
⊢ IsZero ((quotient V c).obj 0)

Tactic:
IsZero.iff_id_eq_zero,

Goal state after:
R : Type u_1
inst✝³ : Semiring R
ι : Type u_2
V : Type u
inst✝² : Category.{v, u} V
inst✝¹ : Preadditive V
c : ComplexShape ι
inst✝ : HasZeroObject V
⊢ 𝟙 ((quotient V c).obj 0) = 0
Module: Mathlib.Algebra.Homology.HomotopyCategory

Goal state before:
pp: R : Type u_1
inst✝³ : Semiring R
ι : Type u_2
V : Type u
inst✝² : Category.{v, u} V
inst✝¹ : Preadditive V
c : ComplexShape ι
inst✝ : CategoryWithHomology V
i : ι
⊢ (homologyFunctor V c i).Additive

Tactic:
have := Functor.additive_of_iso (homologyFunctorFactors V c i).symm
  exact Functor.additive_of_full_essSurj_comp (quotient V c) _

Goal state after:
Module: Mathlib.CategoryTheory.Shift.Induced

Goal state before:
pp: C : Type ?u.2
D : Type ?u.4
inst✝⁵ : Category.{v_1, ?u.2} C
inst✝⁴ : Category.{v_2, ?u.4} D
F : C ⥤ D
A : Type ?u.15
inst✝³ : AddMonoid A
inst✝² : HasShift C A
s : A → D ⥤ D
i : (a : A) → F ⋙ s a ≅ shiftFunctor C a ⋙ F
inst✝¹ : ((whiskeringLeft C D D).obj F).Full
inst✝ : ((whiskeringLeft C D D).obj F).Faithful
m₁ m₂ m₃ : A
⊢ s (m₁ + m₂ + m₃) = s (m₁ + (m₂ + m₃))

Tactic:
rw [add_assoc]

Goal state after:
Module: Mathlib.CategoryTheory.Shift.Induced

Goal state before:
pp: C : Type ?u.2
D : Type ?u.4
inst✝⁵ : Category.{v_1, ?u.2} C
inst✝⁴ : Category.{v_2, ?u.4} D
F : C ⥤ D
A : Type ?u.15
inst✝³ : AddMonoid A
inst✝² : HasShift C A
s : A → D ⥤ D
i : (a : A) → F ⋙ s a ≅ shiftFunctor C a ⋙ F
inst✝¹ : ((whiskeringLeft C D D).obj F).Full
inst✝ : ((whiskeringLeft C D D).obj F).Faithful
m₁ m₂ m₃ : A
X : C
eq :
  F.map ((shiftFunctorAdd C (m₁ + m₂) m₃).hom.app X) ≫
      F.map ((shiftFunctor C m₃).map ((shiftFunctorAdd C m₁ m₂).hom.app X)) =
    F.map (eqToHom ⋯) ≫
      F.map ((shiftFunctorAdd C m₁ (m₂ + m₃)).hom.app X) ≫
        F.map ((shiftFunctorAdd C m₂ m₃).hom.app ((shiftFunctor C m₁).obj X))
⊢ (i (m₁ + m₂ + m₃)).hom.app X ≫
      F.map (eqToHom ⋯) ≫
        F.map ((shiftFunctorAdd C m₁ (m₂ + m₃)).hom.app X) ≫
          F.map ((shiftFunctorAdd C m₂ m₃).hom.app ((shiftFunctor C m₁).obj X)) ≫
            (i m₃).inv.app ((shiftFunctor C m₁ ⋙ shiftFunctor C m₂).obj X) ≫
              (s m₃).map ((i m₂).inv.app ((shiftFunctor C m₁).obj X)) =
    (eqToHom ⋯).app (F.obj X) ≫
      (eqToHom ⋯ ≫ (i (m₁ + m₂ + m₃)).hom.app X ≫ eqToHom ⋯) ≫
        F.map ((shiftFunctorAdd C m₁ (m₂ + m₃)).hom.app X) ≫
          (i (m₂ + m₃)).inv.app ((shiftFunctor C m₁).obj X) ≫
            (s (m₂ + m₃)).map ((i m₁).inv.app X) ≫
              (Induced.add F s i m₂ m₃).hom.app ((s m₁).obj (F.obj X)) ≫ (s m₃).map ((s m₂).map ((i m₁).hom.app X))

Tactic:
simp only [Functor.comp_obj, eqToHom_map, eqToHom_app, NatTrans.naturality_assoc,
          Induced.add_hom_app_obj, Functor.comp_map, Category.assoc, Iso.inv_hom_id_app_assoc,
          eqToHom_trans_assoc, eqToHom_refl, Category.id_comp, Category.comp_id,
          ← Functor.map_comp, Iso.inv_hom_id_app, Functor.map_id]

Goal state after:
Module: Mathlib.CategoryTheory.Shift.CommShift

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁷ : Category.{v_1, u_1} C
inst✝⁶ : Category.{v_2, u_2} D
F₁ F₂ : C ⥤ D
τ : F₁ ⟶ F₂
A : Type u_5
inst✝⁵ : AddMonoid A
inst✝⁴ : HasShift C A
inst✝³ : HasShift D A
inst✝² : F₁.CommShift A
inst✝¹ : F₂.CommShift A
inst✝ : CommShift τ A
a : A
⊢ (Functor.commShiftIso F₁ a).hom ≫ Functor.whiskerRight τ (shiftFunctor D a) =
    (shiftFunctor C a).whiskerLeft τ ≫ (Functor.commShiftIso F₂ a).hom

Tactic:
apply CommShift.shift_comm

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

Goal state before:
pp: case mpr
C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : Preadditive C
inst✝ : ∀ (n : ℤ), (CategoryTheory.shiftFunctor C n).Additive
hC : Pretriangulated C
T : Triangle C
hT : T ∈ distinguishedTriangles
h₁ : T.mor₁ = 0
h₂ : T.mor₂ = 0
f : T.obj₂ ⟶ T.obj₁
hf : 𝟙 T.obj₂ = f ≫ T.mor₁
⊢ IsZero T.obj₂

Tactic:
IsZero.iff_id_eq_zero,

Goal state after:
case mpr
C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : Preadditive C
inst✝ : ∀ (n : ℤ), (CategoryTheory.shiftFunctor C n).Additive
hC : Pretriangulated C
T : Triangle C
hT : T ∈ distinguishedTriangles
h₁ : T.mor₁ = 0
h₂ : T.mor₂ = 0
f : T.obj₂ ⟶ T.obj₁
hf : 𝟙 T.obj₂ = f ≫ T.mor₁
⊢ 𝟙 T.obj₂ = 0
Module: Mathlib.CategoryTheory.Triangulated.Triangulated

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
X₁ X₂ X₃ Z₁₂ Z₂₃ Z₁₃ : C
u₁₂ : X₁ ⟶ X₂
u₂₃ : X₂ ⟶ X₃
u₁₃ : X₁ ⟶ X₃
comm : u₁₂ ≫ u₂₃ = u₁₃
v₁₂ : X₂ ⟶ Z₁₂
w₁₂ : Z₁₂ ⟶ (shiftFunctor C 1).obj X₁
h₁₂ : Triangle.mk u₁₂ v₁₂ w₁₂ ∈ distinguishedTriangles
v₂₃ : X₃ ⟶ Z₂₃
w₂₃ : Z₂₃ ⟶ (shiftFunctor C 1).obj X₂
h₂₃ : Triangle.mk u₂₃ v₂₃ w₂₃ ∈ distinguishedTriangles
v₁₃ : X₃ ⟶ Z₁₃
w₁₃ : Z₁₃ ⟶ (shiftFunctor C 1).obj X₁
h₁₃ : Triangle.mk u₁₃ v₁₃ w₁₃ ∈ distinguishedTriangles
h : Octahedron comm h₁₂ h₂₃ h₁₃
X₁' X₂' X₃' Z₁₂' Z₂₃' Z₁₃' : C
u₁₂' : X₁' ⟶ X₂'
u₂₃' : X₂' ⟶ X₃'
u₁₃' : X₁' ⟶ X₃'
comm' : u₁₂' ≫ u₂₃' = u₁₃'
e₁ : X₁ ≅ X₁'
e₂ : X₂ ≅ X₂'
e₃ : X₃ ≅ X₃'
comm₁₂ : u₁₂ ≫ e₂.hom = e₁.hom ≫ u₁₂'
comm₂₃ : u₂₃ ≫ e₃.hom = e₂.hom ≫ u₂₃'
v₁₂' : X₂' ⟶ Z₁₂'
w₁₂' : Z₁₂' ⟶ (shiftFunctor C 1).obj X₁'
h₁₂' : Triangle.mk u₁₂' v₁₂' w₁₂' ∈ distinguishedTriangles
v₂₃' : X₃' ⟶ Z₂₃'
w₂₃' : Z₂₃' ⟶ (shiftFunctor C 1).obj X₂'
h₂₃' : Triangle.mk u₂₃' v₂₃' w₂₃' ∈ distinguishedTriangles
v₁₃' : X₃' ⟶ Z₁₃'
w₁₃' : Z₁₃' ⟶ (shiftFunctor C 1).obj X₁'
h₁₃' : Triangle.mk u₁₃' v₁₃' w₁₃' ∈ distinguishedTriangles
H : Octahedron comm' h₁₂' h₂₃' h₁₃'
iso₁₂ : Triangle.mk u₁₂ v₁₂ w₁₂ ≅ Triangle.mk u₁₂' v₁₂' w₁₂' :=
  isoTriangleOfIso₁₂ (Triangle.mk u₁₂ v₁₂ w₁₂) (Triangle.mk u₁₂' v₁₂' w₁₂') h₁₂ h₁₂' e₁ e₂ comm₁₂
iso₂₃ : Triangle.mk u₂₃ v₂₃ w₂₃ ≅ Triangle.mk u₂₃' v₂₃' w₂₃' :=
  isoTriangleOfIso₁₂ (Triangle.mk u₂₃ v₂₃ w₂₃) (Triangle.mk u₂₃' v₂₃' w₂₃') h₂₃ h₂₃' e₂ e₃ comm₂₃
⊢ (Triangle.mk u₁₃ v₁₃ w₁₃).mor₁ ≫ e₃.hom = e₁.hom ≫ (Triangle.mk u₁₃' v₁₃' w₁₃').mor₁

Tactic:
by
    dsimp; rw [← comm, assoc, ← comm', ← reassoc_of% comm₁₂, comm₂₃]

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

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : Preadditive C
inst✝ : ∀ (n : ℤ), (CategoryTheory.shiftFunctor C n).Additive
hC : Pretriangulated C
T : Triangle C
hT : T ∈ distinguishedTriangles
⊢ IsZero T.obj₃ ↔ IsIso T.mor₁

Tactic:
by
  refine Iff.trans ?_ (Triangle.isZero₁_iff_isIso₂ _ (inv_rot_of_distTriang _ hT))
  dsimp
  simp only [IsZero.iff_id_eq_zero, ← Functor.map_id, Functor.map_eq_zero_iff]

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

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : Preadditive C
inst✝ : ∀ (n : ℤ), (shiftFunctor C n).Additive
hC : Pretriangulated C
T : Triangle C
hT : T ∈ distinguishedTriangles
hT₀ : T.mor₃ = 0
inr : T.obj₃ ⟶ T.obj₂
inr_snd : inr ≫ T.mor₂ = 𝟙 T.obj₃
fst : T.obj₂ ⟶ T.obj₁
total : fst ≫ T.mor₁ + T.mor₂ ≫ inr = 𝟙 T.obj₂
this : Mono T.mor₁
⊢ BinaryBiproductData T.obj₁ T.obj₃

Tactic:
have eq : fst ≫ T.mor₁ = 𝟙 T.obj₂ - T.mor₂ ≫ inr := by rw [← total, add_sub_cancel_right]

Goal state after:
C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasZeroObject C
inst✝² : HasShift C ℤ
inst✝¹ : Preadditive C
inst✝ : ∀ (n : ℤ), (shiftFunctor C n).Additive
hC : Pretriangulated C
T : Triangle C
hT : T ∈ distinguishedTriangles
hT₀ : T.mor₃ = 0
inr : T.obj₃ ⟶ T.obj₂
inr_snd : inr ≫ T.mor₂ = 𝟙 T.obj₃
fst : T.obj₂ ⟶ T.obj₁
total : fst ≫ T.mor₁ + T.mor₂ ≫ inr = 𝟙 T.obj₂
this : Mono T.mor₁
eq : fst ≫ T.mor₁ = 𝟙 T.obj₂ - T.mor₂ ≫ inr
⊢ BinaryBiproductData T.obj₁ T.obj₃
Module: Mathlib.Algebra.Homology.HomotopyCategory.Pretriangulated

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁵ : Category.{v_1, u_1} C
inst✝⁴ : Category.{v_2, u_2} D
inst✝³ : Preadditive C
inst✝² : HasBinaryBiproducts C
inst✝¹ : Preadditive D
inst✝ : HasBinaryBiproducts D
K L : CochainComplex C ℤ
φ : K ⟶ L
⊢ Cochain.ofHom
      (desc (inr φ) 0 (triangle φ).mor₃ ⋯ ≫
        lift (inr φ) (-(Cocycle.ofHom φ).leftShift 1 1 ⋯) (-(inl φ).leftShift 1 0 ⋯) ⋯) =
    δ (-1) 0 (-(snd (inr φ)).comp ((snd φ).comp (inl (inr φ)) ⋯) ⋯) + Cochain.ofHom (𝟙 (mappingCone (inr φ)))

Tactic:
ext n
      -- the following list of lemmas has been obtained by doing
      -- simp? [ext_to_iff _ _ (n + 1) rfl, ext_from_iff _ (n + 1) _ rfl,
      --   δ_zero_cochain_comp _ _ _ (neg_add_cancel 1),
      --   (inl φ).leftShift_v 1 0 (neg_add_cancel 1) n n (add_zero n) (n + 1) (by lia),
      --   (Cochain.ofHom φ).leftShift_v 1 1 (zero_add 1) n (n + 1) rfl (n + 1) (by lia),
      --   Cochain.comp_v _ _ (add_neg_cancel 1) n (n + 1) n rfl (by lia)]
      simp only [Int.reduceNeg, Cochain.ofHom_comp, ofHom_desc, ofHom_lift, Cocycle.coe_neg,
        Cocycle.leftShift_coe, Cocycle.ofHom_coe, Cochain.comp_zero_cochain_v,
        shiftFunctor_obj_X', δ_neg, δ_zero_cochain_comp _ _ _ (neg_add_cancel 1), δ_inl,
        Int.negOnePow_neg, Int.negOnePow_one, δ_snd, Cochain.neg_comp,
        Cochain.comp_assoc_of_second_is_zero_cochain, smul_neg, Units.neg_smul, one_smul,
        neg_neg, Cochain.comp_add, inr_snd_assoc, neg_add_rev, Cochain.add_v, Cochain.neg_v,
        Cochain.comp_v _ _ (add_neg_cancel 1) n (n + 1) n rfl (by lia),
        Cochain.zero_cochain_comp_v, Cochain.ofHom_v, HomologicalComplex.id_f,
        ext_to_iff _ _ (n + 1) rfl, assoc, liftCochain_v_fst_v,
        (Cochain.ofHom φ).leftShift_v 1 1 (zero_add 1) n (n + 1) rfl (n + 1) (by lia),
        shiftFunctor_obj_X, mul_one, sub_self, mul_zero, Int.zero_ediv, add_zero,
        shiftFunctorObjXIso, HomologicalComplex.XIsoOfEq_rfl, Iso.refl_hom, id_comp,
        Preadditive.add_comp, Preadditive.neg_comp, inl_v_fst_v, comp_id, inr_f_fst_v, comp_zero,
        neg_zero, neg_add_cancel_comm, ext_from_iff _ (n + 1) _ rfl, inl_v_descCochain_v_assoc,
        Cochain.zero_v, zero_comp, Preadditive.comp_neg, inl_v_snd_v_assoc,
        inr_f_descCochain_v_assoc, inr_f_snd_v_assoc, inl_v_triangle_mor₃_f_assoc, triangle_obj₁,
        Iso.refl_inv, inl_v_fst_v_assoc, inr_f_triangle_mor₃_f_assoc, inr_f_fst_v_assoc, and_self,
        liftCochain_v_snd_v,
        (inl φ).leftShift_v 1 0 (neg_add_cancel 1) n n (add_zero n) (n + 1) (by lia),
        Int.negOnePow_zero, inl_v_snd_v, inr_f_snd_v, zero_add, inl_v_descCochain_v,
        inr_f_descCochain_v, inl_v_triangle_mor₃_f, inr_f_triangle_mor₃_f, neg_add_cancel]

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

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝⁵ : Category.{v_1, u_1} C
inst✝⁴ : Category.{v_2, u_2} D
inst✝³ : Preadditive C
inst✝² : HasBinaryBiproducts C
inst✝¹ : Preadditive D
inst✝ : HasBinaryBiproducts D
K L : CochainComplex C ℤ
φ : K ⟶ L
⊢ -(CategoryTheory.shiftFunctor (HomotopyCategory C (ComplexShape.up ℤ)) 1).map
        ((HomotopyCategory.quotient C (ComplexShape.up ℤ)).map φ) =
    (Functor.commShiftIso (HomotopyCategory.quotient C (ComplexShape.up ℤ)) 1).inv.app K ≫
      (-(HomotopyCategory.quotient C (ComplexShape.up ℤ)).map
            ((CategoryTheory.shiftFunctor (CochainComplex C ℤ) 1).map φ)) ≫
        (Functor.commShiftIso (HomotopyCategory.quotient C (ComplexShape.up ℤ)) 1).hom.app L

Tactic:
Preadditive.neg_comp,

Goal state after:
C : Type u_1
D : Type u_2
inst✝⁵ : Category.{v_1, u_1} C
inst✝⁴ : Category.{v_2, u_2} D
inst✝³ : Preadditive C
inst✝² : HasBinaryBiproducts C
inst✝¹ : Preadditive D
inst✝ : HasBinaryBiproducts D
K L : CochainComplex C ℤ
φ : K ⟶ L
⊢ -(CategoryTheory.shiftFunctor (HomotopyCategory C (ComplexShape.up ℤ)) 1).map
        ((HomotopyCategory.quotient C (ComplexShape.up ℤ)).map φ) =
    (Functor.commShiftIso (HomotopyCategory.quotient C (ComplexShape.up ℤ)) 1).inv.app K ≫
      (-(HomotopyCategory.quotient C (ComplexShape.up ℤ)).map
            ((CategoryTheory.shiftFunctor (CochainComplex C ℤ) 1).map φ) ≫
          (Functor.commShiftIso (HomotopyCategory.quotient C (ComplexShape.up ℤ)) 1).hom.app L)
Module: Mathlib.CategoryTheory.Triangulated.Functor

Goal state before:
pp: C : Type u_1
D : Type u_2
inst✝¹⁵ : Category.{v_1, u_1} C
inst✝¹⁴ : Category.{v_2, u_2} D
inst✝¹³ : HasShift C ℤ
inst✝¹² : HasShift D ℤ
inst✝¹¹ : HasZeroObject C
inst✝¹⁰ : HasZeroObject D
inst✝⁹ : Preadditive C
inst✝⁸ : Preadditive D
inst✝⁷ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁵ : Pretriangulated C
inst✝⁴ : Pretriangulated D
F : C ⥤ D
inst✝³ : F.CommShift ℤ
inst✝² : F.IsTriangulated
inst✝¹ : (F.mapComposableArrows 2).EssSurj
inst✝ : IsTriangulated C
⊢ IsTriangulated D

Tactic:
apply IsTriangulated.mk
  intro Y₁ Y₂ Y₃ Z₁₂ Z₂₃ Z₁₃ u₁₂ u₂₃ u₁₃ comm v₁₂ w₁₂ h₁₂ v₂₃ w₂₃ h₂₃ v₁₃ w₁₃ h₁₃
  obtain ⟨α, ⟨e⟩⟩ : ∃ (α : ComposableArrows C 2),
      Nonempty ((F.mapComposableArrows 2).obj α ≅ ComposableArrows.mk₂ u₁₂ u₂₃) :=
    ⟨_, ⟨Functor.objObjPreimageIso _ _⟩⟩
  obtain ⟨X₁, X₂, X₃, f, g, rfl⟩ := ComposableArrows.mk₂_surjective α
  obtain ⟨_, _, _, h₁₂'⟩ := distinguished_cocone_triangle f
  obtain ⟨_, _, _, h₂₃'⟩ := distinguished_cocone_triangle g
  obtain ⟨_, _, _, h₁₃'⟩ := distinguished_cocone_triangle (f ≫ g)
  exact ⟨Octahedron.ofIso (e₁ := (e.app 0).symm) (e₂ := (e.app 1).symm) (e₃ := (e.app 2).symm)
    (comm₁₂ := ComposableArrows.naturality' e.inv 0 1)
    (comm₂₃ := ComposableArrows.naturality' e.inv 1 2)
    (H := (someOctahedron rfl h₁₂' h₂₃' h₁₃').map F) ..⟩

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

Goal state before:
pp: case refine_1
C : Type u_1
inst✝⁶ : Category.{v_1, u_1} 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
inst✝ : IsTriangulated C
X₁ X₂ X₃ Z₁₂ Z₂₃ Z₁₃ : C
u₁₂ : X₁ ⟶ X₂
u₂₃ : X₂ ⟶ X₃
u₁₃ : X₁ ⟶ X₃
comm : u₁₂ ≫ u₂₃ = u₁₃
v₁₂ : Z₁₂ ⟶ X₁
w₁₂ : X₂ ⟶ (shiftFunctor C 1).obj Z₁₂
h₁₂ : Triangle.mk v₁₂ u₁₂ w₁₂ ∈ distinguishedTriangles
v₂₃ : Z₂₃ ⟶ X₂
w₂₃ : X₃ ⟶ (shiftFunctor C 1).obj Z₂₃
h₂₃ : Triangle.mk v₂₃ u₂₃ w₂₃ ∈ distinguishedTriangles
v₁₃ : Z₁₃ ⟶ X₁
w₁₃ : X₃ ⟶ (shiftFunctor C 1).obj Z₁₃
h₁₃ : Triangle.mk v₁₃ u₁₃ w₁₃ ∈ distinguishedTriangles
o : Octahedron comm ⋯ ⋯ ⋯ := someOctahedron comm ⋯ ⋯ ⋯
m₁ : Z₁₂ ⟶ Z₁₃ := (shiftShiftNeg Z₁₂ 1).inv ≫ (shiftFunctor C (-1)).map o.m₁ ≫ (shiftShiftNeg Z₁₃ 1).hom
m₃ : Z₁₃ ⟶ Z₂₃ := (shiftShiftNeg Z₁₃ 1).inv ≫ (shiftFunctor C (-1)).map o.m₃ ≫ (shiftShiftNeg Z₂₃ 1).hom
eq₁ : w₁₂ ≫ o.m₁ = u₂₃ ≫ w₁₃
eq₂ : o.m₁ ≫ (shiftFunctor C 1).map v₁₃ = (shiftFunctor C 1).map v₁₂
eq₃ : w₁₃ ≫ o.m₃ = w₂₃
eq₄ : (shiftFunctor C 1).map v₁₃ ≫ (shiftFunctor C 1).map u₁₂ = o.m₃ ≫ (shiftFunctor C 1).map v₂₃
⊢ m₁ ≫ v₁₃ = v₁₂

Tactic:
← shiftFunctorCompIsoId_naturality_1 v₁₃ 1 (-1) (Int.add_right_neg 1)

Goal state after:
case refine_1
C : Type u_1
inst✝⁶ : Category.{v_1, u_1} 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
inst✝ : IsTriangulated C
X₁ X₂ X₃ Z₁₂ Z₂₃ Z₁₃ : C
u₁₂ : X₁ ⟶ X₂
u₂₃ : X₂ ⟶ X₃
u₁₃ : X₁ ⟶ X₃
comm : u₁₂ ≫ u₂₃ = u₁₃
v₁₂ : Z₁₂ ⟶ X₁
w₁₂ : X₂ ⟶ (shiftFunctor C 1).obj Z₁₂
h₁₂ : Triangle.mk v₁₂ u₁₂ w₁₂ ∈ distinguishedTriangles
v₂₃ : Z₂₃ ⟶ X₂
w₂₃ : X₃ ⟶ (shiftFunctor C 1).obj Z₂₃
h₂₃ : Triangle.mk v₂₃ u₂₃ w₂₃ ∈ distinguishedTriangles
v₁₃ : Z₁₃ ⟶ X₁
w₁₃ : X₃ ⟶ (shiftFunctor C 1).obj Z₁₃
h₁₃ : Triangle.mk v₁₃ u₁₃ w₁₃ ∈ distinguishedTriangles
o : Octahedron comm ⋯ ⋯ ⋯ := someOctahedron comm ⋯ ⋯ ⋯
m₁ : Z₁₂ ⟶ Z₁₃ := (shiftShiftNeg Z₁₂ 1).inv ≫ (shiftFunctor C (-1)).map o.m₁ ≫ (shiftShiftNeg Z₁₃ 1).hom
m₃ : Z₁₃ ⟶ Z₂₃ := (shiftShiftNeg Z₁₃ 1).inv ≫ (shiftFunctor C (-1)).map o.m₃ ≫ (shiftShiftNeg Z₂₃ 1).hom
eq₁ : w₁₂ ≫ o.m₁ = u₂₃ ≫ w₁₃
eq₂ : o.m₁ ≫ (shiftFunctor C 1).map v₁₃ = (shiftFunctor C 1).map v₁₂
eq₃ : w₁₃ ≫ o.m₃ = w₂₃
eq₄ : (shiftFunctor C 1).map v₁₃ ≫ (shiftFunctor C 1).map u₁₂ = o.m₃ ≫ (shiftFunctor C 1).map v₂₃
⊢ m₁ ≫
      (shiftFunctorCompIsoId C 1 (-1) ⋯).inv.app Z₁₃ ≫
        (shiftFunctor C (-1)).map ((shiftFunctor C 1).map v₁₃) ≫ (shiftFunctorCompIsoId C 1 (-1) ⋯).hom.app X₁ =
    v₁₂
Module: Mathlib.CategoryTheory.Category.Quiv

Goal state before:
pp: C : Type u
inst✝ : Category.{v, u} C
⊢ Paths.of C ⋙q (pathComposition C).toPrefunctor = 𝟭q C

Tactic:
by
  dsimp only [Prefunctor.comp]
  congr
  funext X Y f
  exact Category.id_comp _

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

Goal state before:
pp: case refine_2.inl
C : Type uC
inst✝¹ : Category.{uC', uC} C
W : MorphismProperty C
D : Type uD
inst✝ : Category.{uD', uD} D
G₁ G₂ : W.Localization ⥤ D
h : W.Q ⋙ G₁ = W.Q ⋙ G₂
X Y : C
f : { obj := X }.obj ⟶ { obj := Y }.obj
⊢ (Quotient.functor (relations W) ⋙ G₁).map (Quiver.Hom.toPath (Sum.inl f)) =
    eqToHom ⋯ ≫ (Quotient.functor (relations W) ⋙ G₂).map (Quiver.Hom.toPath (Sum.inl f)) ≫ eqToHom ⋯

Tactic:
simpa only using! Functor.congr_hom h f

Goal state after:
Module: Mathlib.CategoryTheory.CatCommSq

Goal state before:
pp: C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
C₄ : Type u_4
inst✝³ : Category.{v_1, u_1} C₁
inst✝² : Category.{v_2, u_2} C₂
inst✝¹ : Category.{v_3, u_3} C₃
inst✝ : Category.{v_4, u_4} C₄
T : C₁ ≌ C₂
L : C₁ ⥤ C₃
R : C₂ ⥤ C₄
B : C₃ ≌ C₄
h : CatCommSq T.functor L R B.functor
X : C₁
⊢ (iso T.symm.inverse L R B.symm.inverse).hom.app X ≫ B.functor.map (L.map (T.unitIso.hom.app X)) =
    (iso T.symm.inverse L R B.symm.inverse).hom.app X ≫ B.functor.map (L.map (T.unitIso.hom.app X))

Tactic:
rw [← Functor.comp_map]

Goal state after:
C₁ : Type u_1
C₂ : Type u_2
C₃ : Type u_3
C₄ : Type u_4
inst✝³ : Category.{v_1, u_1} C₁
inst✝² : Category.{v_2, u_2} C₂
inst✝¹ : Category.{v_3, u_3} C₃
inst✝ : Category.{v_4, u_4} C₄
T : C₁ ≌ C₂
L : C₁ ⥤ C₃
R : C₂ ⥤ C₄
B : C₃ ≌ C₄
h : CatCommSq T.functor L R B.functor
X : C₁
⊢ (iso T.symm.inverse L R B.symm.inverse).hom.app X ≫ (L ⋙ B.functor).map (T.unitIso.hom.app X) =
    (iso T.symm.inverse L R B.symm.inverse).hom.app X ≫ (L ⋙ B.functor).map (T.unitIso.hom.app X)