Theorem: CategoryTheory.ShortComplex.Splitting.rightHomologyData_ι
File: Mathlib/Algebra/Homology/ShortComplex/Exact.lean

Proof steps:
state_before: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
⊢ S.RightHomologyData
state_after: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
⊢ S.RightHomologyData
tactic: have hp := CokernelCofork.IsColimit.ofπ S.g S.zero
    (fun x _ => s.s ≫ x)
    (fun x hx => by simp only [s.g_s_assoc, sub_comp, id_comp, sub_eq_self, assoc, hx, comp_zero])
    (fun x _ b hb => by simp only [← hb, s.s_g_assoc])
state_before: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
⊢ S.RightHomologyData
state_after: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
⊢ S.RightHomologyData
tactic: let g' := hp.desc (CokernelCofork.ofπ S.g S.zero)
state_before: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
⊢ S.RightHomologyData
state_after: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
⊢ S.RightHomologyData
tactic: have hg' : g' = 𝟙 _ := by
    apply Cofork.IsColimit.hom_ext hp
    dsimp
    erw [Cofork.IsColimit.π_desc hp]
    simp only [Cofork.π_ofπ, comp_id]
state_before: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
⊢ S.RightHomologyData
state_after: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
wι : 0 ≫ g' = 0
⊢ S.RightHomologyData
tactic: have wι : (0 : 0 ⟶ S.X₃) ≫ g' = 0 := zero_comp
state_before: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
wι : 0 ≫ g' = 0
⊢ S.RightHomologyData
state_after: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
wι : 0 ≫ g' = 0
hι : IsLimit (KernelFork.ofι 0 wι)
⊢ S.RightHomologyData
tactic: have hι : IsLimit (KernelFork.ofι 0 wι) := KernelFork.IsLimit.ofMonoOfIsZero _
      (by rw [hg']; dsimp; infer_instance) (isZero_zero _)
state_before: C : Type u_1
D : Type u_2
inst✝⁴ : Category.{?u.88317, u_1} C
inst✝³ : Category.{?u.88321, u_2} D
inst✝² : Preadditive C
inst✝¹ : Preadditive D
S : ShortComplex C
inst✝ : HasZeroObject C
s : S.Splitting
hp : IsColimit (CokernelCofork.ofπ S.g ⋯)
g' : (CokernelCofork.ofπ S.g ⋯).pt ⟶ (CokernelCofork.ofπ S.g ⋯).pt := hp.desc (CokernelCofork.ofπ S.g ⋯)
hg' : g' = 𝟙 (CokernelCofork.ofπ S.g ⋯).pt
wι : 0 ≫ g' = 0
hι : IsLimit (KernelFork.ofι 0 wι)
⊢ S.RightHomologyData
state_after: no goals
tactic: exact
    { Q := S.X₃
      H := 0
      p := S.g
      wp := S.zero
      hp := hp
      ι := 0
      wι := wι
      hι := hι }