awhecmu/canonical-drafter-extract-mathlib huggingface dataset:
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
pos :
  ∀ (h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))),
    HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
        (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂))
          (K.d₂ c₁₂ i₁ (c₂.next i₂) i₁₂'')) =
      0
⊢ HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂))
        (K.d₂ c₁₂ i₁ (c₂.next i₂) i₁₂'')) =
    0
have neg : ∀ (h₄ : ¬c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))),
  HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂))
        (K.d₂ c₁₂ i₁ (c₂.next i₂) i₁₂'')) =
    0
Tactic: by_cases h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
⊢ HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂))
        (K.d₂ c₁₂ i₁ (c₂.next i₂) i₁₂'')) =
    0
have pos : c₁.π c₂ c₁₂ (i₁, c₂.next (c₂.next i₂)) = i₁₂''
Tactic: rw [totalAux.d₂_eq K c₁₂ i₁ h₄ i₁₂'', Linear.comp_units_smul,
            HomologicalComplex.d_comp_d_assoc, zero_comp, smul_zero, smul_zero]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
⊢ c₁.π c₂ c₁₂ (i₁, c₂.next (c₂.next i₂)) = i₁₂''
have pos : c₁₂.next (c₁.π c₂ c₁₂ (i₁, c₂.next i₂)) = i₁₂''
Tactic: rw [← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₄, ← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₃,
            h, c₁₂.next_eq' h₁, c₁₂.next_eq' h₂]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
pos : c₁₂.next (c₁.π c₂ c₁₂ (i₁, c₂.next i₂)) = i₁₂''
⊢ c₁.π c₂ c₁₂ (i₁, c₂.next (c₂.next i₂)) = i₁₂''
have pos₁ : c₁₂.next (c₁₂.next (c₁.π c₂ c₁₂ (i₁, i₂))) = i₁₂''
Tactic: rw [← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₄, ← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₃,
            h, c₁₂.next_eq' h₁, c₁₂.next_eq' h₂]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
pos : c₁₂.next (c₁.π c₂ c₁₂ (i₁, c₂.next i₂)) = i₁₂''
pos₁ : c₁₂.next (c₁₂.next (c₁.π c₂ c₁₂ (i₁, i₂))) = i₁₂''
⊢ c₁.π c₂ c₁₂ (i₁, c₂.next (c₂.next i₂)) = i₁₂''
have pos₂ : c₁₂.next (c₁₂.next i₁₂) = i₁₂''
Tactic: rw [← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₄, ← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₃,
            h, c₁₂.next_eq' h₁, c₁₂.next_eq' h₂]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
pos : c₁₂.next (c₁.π c₂ c₁₂ (i₁, c₂.next i₂)) = i₁₂''
pos₁ : c₁₂.next (c₁₂.next (c₁.π c₂ c₁₂ (i₁, i₂))) = i₁₂''
pos₂ : c₁₂.next (c₁₂.next i₁₂) = i₁₂''
⊢ c₁.π c₂ c₁₂ (i₁, c₂.next (c₂.next i₂)) = i₁₂''
have pos₃ : c₁₂.next i₁₂' = i₁₂''
Tactic: rw [← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₄, ← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₃,
            h, c₁₂.next_eq' h₁, c₁₂.next_eq' h₂]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
pos : c₁₂.next (c₁.π c₂ c₁₂ (i₁, c₂.next i₂)) = i₁₂''
pos₁ : c₁₂.next (c₁₂.next (c₁.π c₂ c₁₂ (i₁, i₂))) = i₁₂''
pos₂ : c₁₂.next (c₁₂.next i₁₂) = i₁₂''
pos₃ : c₁₂.next i₁₂' = i₁₂''
⊢ c₁.π c₂ c₁₂ (i₁, c₂.next (c₂.next i₂)) = i₁₂''
have pos₄ : i₁₂'' = i₁₂''
Tactic: rw [← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₄, ← ComplexShape.next_π₂ c₁ c₁₂ i₁ h₃,
            h, c₁₂.next_eq' h₁, c₁₂.next_eq' h₂]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : ¬c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
⊢ HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂))
        (K.d₂ c₁₂ i₁ (c₂.next i₂) i₁₂'')) =
    0
have neg : HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
    (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂)) 0) =
  0
Tactic: rw [K.d₂_eq_zero c₁₂ _ _ _ h₄, comp_zero, smul_zero]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : ¬c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
neg :
  HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂)) 0) =
    0
⊢ HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂))
        (K.d₂ c₁₂ i₁ (c₂.next i₂) i₁₂'')) =
    0
have neg₁ : HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂)) 0 = 0
Tactic: rw [K.d₂_eq_zero c₁₂ _ _ _ h₄, comp_zero, smul_zero]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : c₂.Rel i₂ (c₂.next i₂)
h₄ : ¬c₂.Rel (c₂.next i₂) (c₂.next (c₂.next i₂))
neg :
  HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂)) 0) =
    0
neg₁ :
  HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂)) 0 =
    0
⊢ HSMul.hSMul (β := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (c₁.ε₂ c₂ c₁₂ (i₁, i₂))
      (CategoryStruct.comp (Y := (K.X i₁).X (c₂.next i₂)) ((K.X i₁).d i₂ (c₂.next i₂))
        (K.d₂ c₁₂ i₁ (c₂.next i₂) i₁₂'')) =
    0
have neg₂ : Eq.{v_1 + 1} (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') 0 0
Tactic: rw [K.d₂_eq_zero c₁₂ _ _ _ h₄, comp_zero, smul_zero]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : ¬c₂.Rel i₂ (c₂.next i₂)
⊢ Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
have neg : Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (0 ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
Tactic: rw [K.d₂_eq_zero c₁₂ _ _ _ h₃, zero_comp]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
h₃ : ¬c₂.Rel i₂ (c₂.next i₂)
neg : Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') (0 ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
⊢ Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
have neg₁ : Eq.{v_1 + 1} (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') 0 0
Tactic: rw [K.d₂_eq_zero c₁₂ _ _ _ h₃, zero_comp]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : ¬c₁₂.Rel i₁₂' i₁₂''
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
have neg : Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
  (K.D₂ c₁₂ i₁₂ i₁₂' ≫ 0) 0
Tactic: rw [K.D₂_shape c₁₂ _ _ h₂, comp_zero]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : ¬c₁₂.Rel i₁₂' i₁₂''
neg :
  Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ 0) 0
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
have neg₁ : Eq.{v_1 + 1} (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') 0 0
Tactic: rw [K.D₂_shape c₁₂ _ _ h₂, comp_zero]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : ¬c₁₂.Rel i₁₂ i₁₂'
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
have neg : Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
  (0 ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
Tactic: rw [K.D₂_shape c₁₂ _ _ h₁, zero_comp]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : ¬c₁₂.Rel i₁₂ i₁₂'
neg :
  Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (0 ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'') 0
have neg₁ : Eq.{v_1 + 1} (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'') 0 0
Tactic: rw [K.D₂_shape c₁₂ _ _ h₁, zero_comp]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
have pos : ∀ (h₁ : c₁₂.Rel i₁₂ i₁₂'),
  Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
Tactic: by_cases h₁ : c₁₂.Rel i₁₂ i₁₂'
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
pos :
  ∀ (h₁ : c₁₂.Rel i₁₂ i₁₂'),
    Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
      (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
have neg : ∀ (h₁ : ¬c₁₂.Rel i₁₂ i₁₂'),
  Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
Tactic: by_cases h₁ : c₁₂.Rel i₁₂ i₁₂'
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
have pos : ∀ (h₂ : c₁₂.Rel i₁₂' i₁₂''),
  Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
Tactic: by_cases h₂ : c₁₂.Rel i₁₂' i₁₂''
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
pos :
  ∀ (h₂ : c₁₂.Rel i₁₂' i₁₂''),
    Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
      (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
have neg : ∀ (h₂ : ¬c₁₂.Rel i₁₂' i₁₂''),
  Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
Tactic: by_cases h₂ : c₁₂.Rel i₁₂' i₁₂''
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
⊢ Eq (α := K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂ ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
have pos : ∀ (i₁ : I₁) (i₂ : I₂) (h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂),
  Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.toGradedObject.ιMapObj (c₁.π c₂ c₁₂) (i₁, i₂) i₁₂ h ≫ K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'')
    (K.toGradedObject.ιMapObj (c₁.π c₂ c₁₂) (i₁, i₂) i₁₂ h ≫ (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂''))
Tactic: ext ⟨i₁, i₂⟩ h
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
⊢ Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.toGradedObject.ιMapObj (c₁.π c₂ c₁₂) (i₁, i₂) i₁₂ h ≫ K.D₂ c₁₂ i₁₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'')
    (K.toGradedObject.ιMapObj (c₁.π c₂ c₁₂) (i₁, i₂) i₁₂ h ≫ (-K.D₁ c₁₂ i₁₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂''))
have pos : Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
  (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.d₁ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
Tactic: simp only [totalAux.ιMapObj_D₂_assoc, comp_neg, totalAux.ιMapObj_D₁_assoc]
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
⊢ Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.d₁ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
have pos : ∀ (h₃ : c₁.Rel i₁ (c₁.next i₁)),
  Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.d₁ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
Tactic: by_cases h₃ : c₁.Rel i₁ (c₁.next i₁)
-- Lean 4 proof step from Mathlib.Algebra.Homology.TotalComplex (goal)
Goal:
C : Type u_1
inst : Category.{v_1, u_1} C
inst_1 : Preadditive.{v_1, u_1} C
I₁ : Type u_2
I₂ : Type u_3
I₁₂ : Type u_4
c₁ : ComplexShape I₁
c₂ : ComplexShape I₂
K : HomologicalComplex₂.{v_1, u_1, u_2, u_3} C c₁ c₂
c₁₂ : ComplexShape I₁₂
inst_2 : TotalComplexShape c₁ c₂ c₁₂
inst_3 : DecidableEq I₁₂
inst_4 : K.HasTotal c₁₂
i₁₂ i₁₂' i₁₂'' : I₁₂
h₁ : c₁₂.Rel i₁₂ i₁₂'
h₂ : c₁₂.Rel i₁₂' i₁₂''
i₁ : I₁
i₂ : I₂
h : c₁.π c₂ c₁₂ (i₁, i₂) = i₁₂
pos :
  ∀ (h₃ : c₁.Rel i₁ (c₁.next i₁)),
    Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
      (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.d₁ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
⊢ Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.d₁ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
have neg : ∀ (h₃ : ¬c₁.Rel i₁ (c₁.next i₁)),
  Eq (α := K.toGradedObject (i₁, i₂) ⟶ K.toGradedObject.mapObj (c₁.π c₂ c₁₂) i₁₂'')
    (K.d₂ c₁₂ i₁ i₂ i₁₂' ≫ K.D₁ c₁₂ i₁₂' i₁₂'') (-K.d₁ c₁₂ i₁ i₂ i₁₂' ≫ K.D₂ c₁₂ i₁₂' i₁₂'')
Tactic: by_cases h₃ : c₁.Rel i₁ (c₁.next i₁)