-- Mathlib/CategoryTheory/Triangulated/Functor.lean
lemma isTriangulated_iff_of_iso {F₁ F₂ : C ⥤ D} (e : F₁ ≅ F₂) [F₁.CommShift ℤ] [F₂.CommShift ℤ]
    [NatTrans.CommShift e.hom ℤ] : F₁.IsTriangulated ↔ F₂.IsTriangulated

Proof state:
case mp
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
a✝ : F₁.IsTriangulated
⊢ F₂.IsTriangulated

Tactic:
exact isTriangulated_of_iso e

Result:
no goals

Proof state:
case mpr
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
a✝ : F₂.IsTriangulated
⊢ F₁.IsTriangulated

Tactic:
have : NatTrans.CommShift e.symm.hom ℤ := inferInstanceAs (NatTrans.CommShift e.inv ℤ)

Result:
case mpr
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
a✝ : F₂.IsTriangulated
this : NatTrans.CommShift e.symm.hom ℤ
⊢ F₁.IsTriangulated

Proof state:
case mpr
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
a✝ : F₂.IsTriangulated
this : NatTrans.CommShift e.symm.hom ℤ
⊢ F₁.IsTriangulated

Tactic:
exact isTriangulated_of_iso e.symm

Result:
no goals

Proof state:
case mp
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
⊢ F₁.IsTriangulated → F₂.IsTriangulated

Tactic:
intro

Result:
case mp
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
a✝ : F₁.IsTriangulated
⊢ F₂.IsTriangulated

Proof state:
case mpr
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
⊢ F₂.IsTriangulated → F₁.IsTriangulated

Tactic:
intro

Result:
case mpr
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
a✝ : F₂.IsTriangulated
⊢ F₁.IsTriangulated

Proof state:
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
⊢ F₁.IsTriangulated ↔ F₂.IsTriangulated

Tactic:
constructor

Result:
case mp
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
⊢ F₁.IsTriangulated → F₂.IsTriangulated

case mpr
C : Type u_1
D : Type u_2
inst✝¹⁴ : Category.{u_4, u_1} C
inst✝¹³ : Category.{u_5, u_2} D
inst✝¹² : HasShift C ℤ
inst✝¹¹ : HasShift D ℤ
inst✝¹⁰ : HasZeroObject C
inst✝⁹ : HasZeroObject D
inst✝⁸ : Preadditive C
inst✝⁷ : Preadditive D
inst✝⁶ : ∀ (n : ℤ), (shiftFunctor C n).Additive
inst✝⁵ : ∀ (n : ℤ), (shiftFunctor D n).Additive
inst✝⁴ : Pretriangulated C
inst✝³ : Pretriangulated D
F₁ F₂ : C ⥤ D
e : F₁ ≅ F₂
inst✝² : F₁.CommShift ℤ
inst✝¹ : F₂.CommShift ℤ
inst✝ : NatTrans.CommShift e.hom ℤ
⊢ F₂.IsTriangulated → F₁.IsTriangulated