Module: Mathlib.Algebra.Homology.SpectralObject.SpectralSequence

Goal state before:
pp: case pos
C : Type u_1
ι : Type u_2
κ : Type u_3
inst✝³ : Category.{v_1, u_1} C
inst✝² : Abelian C
inst✝¹ : Preorder ι
X : SpectralObject C ι
c : ℤ → ComplexShape κ
r₀ : ℤ
data : SpectralSequenceDataCore ι c r₀
r r' : ℤ
hrr' : r + 1 = r'
hr : r₀ ≤ r
pq' pq'' : κ
hpq' : (c r).next pq' = pq''
i₀' i₀ i₁ i₂ i₃ : ι
hi₀' : i₀' = data.i₀ r' pq' ⋯
hi₀ : i₀ = data.i₀ r pq' ⋯
hi₁ : i₁ = data.i₁ pq'
hi₂ : i₂ = data.i₂ pq'
hi₃ : i₃ = data.i₃ r pq' ⋯
n₀ n₁ n₂ : ℤ
hn₁' : n₁ = data.deg pq'
inst✝ : X.HasSpectralSequence data
hn₁ : n₀ + 1 = n₁
hn₂ : n₁ + 1 = n₂
h : (c r).Rel pq' pq''
⊢ (kfSc X data r r' hrr' hr pq' pq'' i₀' i₀ i₁ i₂ i₃ hi₀' hi₀ hi₁ hi₂ hi₃ n₀ n₁ n₂ hn₁' hn₁ hn₂).Exact

pp: case neg
C : Type u_1
ι : Type u_2
κ : Type u_3
inst✝³ : Category.{v_1, u_1} C
inst✝² : Abelian C
inst✝¹ : Preorder ι
X : SpectralObject C ι
c : ℤ → ComplexShape κ
r₀ : ℤ
data : SpectralSequenceDataCore ι c r₀
r r' : ℤ
hrr' : r + 1 = r'
hr : r₀ ≤ r
pq' pq'' : κ
hpq' : (c r).next pq' = pq''
i₀' i₀ i₁ i₂ i₃ : ι
hi₀' : i₀' = data.i₀ r' pq' ⋯
hi₀ : i₀ = data.i₀ r pq' ⋯
hi₁ : i₁ = data.i₁ pq'
hi₂ : i₂ = data.i₂ pq'
hi₃ : i₃ = data.i₃ r pq' ⋯
n₀ n₁ n₂ : ℤ
hn₁' : n₁ = data.deg pq'
inst✝ : X.HasSpectralSequence data
hn₁ : n₀ + 1 = n₁
hn₂ : n₁ + 1 = n₂
h : ¬(c r).Rel pq' pq''
⊢ (kfSc X data r r' hrr' hr pq' pq'' i₀' i₀ i₁ i₂ i₃ hi₀' hi₀ hi₁ hi₂ hi₃ n₀ n₁ n₂ hn₁' hn₁ hn₂).Exact

Tactic:
· refine ShortComplex.exact_of_iso (Iso.symm ?_)
      (X.dKernelSequence_exact
        (homOfLE (show data.i₀ r pq'' ≤ i₀' by
          simpa only [hi₀', data.i₀_prev r r' _ _ h] using data.le₀₁ r pq''))
        (homOfLE (data.i₀_le' hrr' hr pq' hi₀' hi₀)) (homOfLE (data.le₀₁' r hr pq' hi₀ hi₁))
        (homOfLE (data.le₁₂' pq' hi₁ hi₂)) (homOfLE (data.le₂₃' r hr pq' hi₂ hi₃)) _ rfl
        n₀ n₁ n₂ (n₂ + 1) hn₁ hn₂ rfl)
    refine ShortComplex.isoMk (Iso.refl _)
      (pageXIso X data _ hr _ _ _ _ _ hi₀ hi₁ hi₂ hi₃ _ _ _ hn₁')
      (pageXIso X data _ hr _ _ _ _ _ rfl (by rw [hi₀', data.i₀_prev r r' _ _ h])
      (by rw [hi₀, data.hc₀₂ r _ _ h]) (by rw [hi₁, data.hc₁₃ r _ _ h]) _ _ _
      (by have := data.hc r _ _ h; lia)) ?_ ?_
    · simp
    · dsimp
      rw [pageD_eq X data r hr pq' pq'' h
        (homOfLE (data.le₀₁' r hr pq'' rfl (by simpa [← data.i₀_prev r r' _ _ h])))
        (homOfLE (data.i₀_le' hrr' hr pq' hi₀' hi₀)) (homOfLE (data.le₀₁' r hr pq' hi₀ hi₁))
        (homOfLE (data.le₁₂' pq' hi₁ hi₂)) (homOfLE (data.le₂₃' r hr pq' hi₂ hi₃))
        rfl (by rw [hi₀', data.i₀_prev r r' _ _ h]) hi₀ hi₁ hi₂ hi₃ n₀ n₁ n₂ (n₂ + 1) hn₁',
        Category.assoc, Category.assoc, Iso.inv_hom_id, Category.comp_id]

Goal state after:
case neg
C : Type u_1
ι : Type u_2
κ : Type u_3
inst✝³ : Category.{v_1, u_1} C
inst✝² : Abelian C
inst✝¹ : Preorder ι
X : SpectralObject C ι
c : ℤ → ComplexShape κ
r₀ : ℤ
data : SpectralSequenceDataCore ι c r₀
r r' : ℤ
hrr' : r + 1 = r'
hr : r₀ ≤ r
pq' pq'' : κ
hpq' : (c r).next pq' = pq''
i₀' i₀ i₁ i₂ i₃ : ι
hi₀' : i₀' = data.i₀ r' pq' ⋯
hi₀ : i₀ = data.i₀ r pq' ⋯
hi₁ : i₁ = data.i₁ pq'
hi₂ : i₂ = data.i₂ pq'
hi₃ : i₃ = data.i₃ r pq' ⋯
n₀ n₁ n₂ : ℤ
hn₁' : n₁ = data.deg pq'
inst✝ : X.HasSpectralSequence data
hn₁ : n₀ + 1 = n₁
hn₂ : n₁ + 1 = n₂
h : ¬(c r).Rel pq' pq''
⊢ (kfSc X data r r' hrr' hr pq' pq'' i₀' i₀ i₁ i₂ i₃ hi₀' hi₀ hi₁ hi₂ hi₃ n₀ n₁ n₂ hn₁' hn₁ hn₂).Exact