Module: Mathlib.AlgebraicGeometry.AffineTransitionLimit

Goal state before:
pp: I : Type u
inst✝⁵ : Category.{u, u} I
S X : Scheme
D : I ⥤ Scheme
t : D ⟶ (Functor.const I).obj S
f : X ⟶ S
inst✝⁴ : ∀ (i : I), CompactSpace ↥(D.obj i)
inst✝³ : LocallyOfFiniteType f
inst✝² : IsCofiltered I
inst✝¹ : ∀ {i j : I} (f : i ⟶ j), IsAffineHom (D.map f)
A : ExistsHomHomCompEqCompAux D t f
inst✝ : ∀ (i : I), IsAffineHom (A.c.π.app i)
j : A.𝒰D.I₀
this✝² : IsAffine (A.𝒰D.X j)
this✝¹ : ∀ (i : Over A.i'), IsAffine ((Over.post D ⋙ Over.pullback (A.𝒰D.f j) ⋙ Over.forget (A.𝒰D.X j)).obj i)
this✝ : IsAffine ((Over.pullback (A.𝒰D.f j) ⋙ Over.forget (A.𝒰D.X j)).mapCone ((Over.conePost D A.i').obj A.c)).pt
this : LocallyOfFiniteType ((A.𝒰X j.fst.fst).f j.fst.snd ≫ Scheme.Cover.pullbackHom A.𝒰S f j.fst.fst)
H₁ :
  (pullback.fst A.g ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫ A.g) ≫
      pullback.fst f f =
    (pullback.snd A.g ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
        (Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
      pullback.fst f f
H₂ :
  (pullback.fst A.g ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫ A.g) ≫
      pullback.snd f f =
    (pullback.snd A.g ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
        (Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
      pullback.snd f f
⊢ ∃ k hki',
    (Precoverage.ZeroHypercover.pullback₁ (D.map hki') A.𝒰D).f j ≫ D.map (hki' ≫ A.hii') ≫ A.a =
      (Precoverage.ZeroHypercover.pullback₁ (D.map hki') A.𝒰D).f j ≫ D.map (hki' ≫ A.hii') ≫ A.b

Tactic:
simp only [Scheme.Pullback.openCoverOfBase_I₀, Scheme.Pullback.openCoverOfBase_X,
    Scheme.Cover.pullbackHom, Scheme.Pullback.openCoverOfLeftRight_I₀,
    g, Category.assoc, limit.lift_π, PullbackCone.mk_pt, PullbackCone.mk_π_app,
    Scheme.Pullback.diagonalCover_map] at H₁ H₂

Goal state after:
I : Type u
inst✝⁵ : Category.{u, u} I
S X : Scheme
D : I ⥤ Scheme
t : D ⟶ (Functor.const I).obj S
f : X ⟶ S
inst✝⁴ : ∀ (i : I), CompactSpace ↥(D.obj i)
inst✝³ : LocallyOfFiniteType f
inst✝² : IsCofiltered I
inst✝¹ : ∀ {i j : I} (f : i ⟶ j), IsAffineHom (D.map f)
A : ExistsHomHomCompEqCompAux D t f
inst✝ : ∀ (i : I), IsAffineHom (A.c.π.app i)
j : A.𝒰D.I₀
this✝² : IsAffine (A.𝒰D.X j)
this✝¹ : ∀ (i : Over A.i'), IsAffine ((Over.post D ⋙ Over.pullback (A.𝒰D.f j) ⋙ Over.forget (A.𝒰D.X j)).obj i)
this✝ : IsAffine ((Over.pullback (A.𝒰D.f j) ⋙ Over.forget (A.𝒰D.X j)).mapCone ((Over.conePost D A.i').obj A.c)).pt
this : LocallyOfFiniteType ((A.𝒰X j.fst.fst).f j.fst.snd ≫ Scheme.Cover.pullbackHom A.𝒰S f j.fst.fst)
H₁ :
  pullback.fst (D.map A.hii' ≫ pullback.lift A.a A.b ⋯)
        ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
      D.map A.hii' ≫ A.a =
    pullback.snd (D.map A.hii' ≫ pullback.lift A.a A.b ⋯)
        ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
      pullback.fst ((A.𝒰X j.fst.fst).f j.fst.snd ≫ pullback.snd f (A.𝒰S.f j.fst.fst))
          ((A.𝒰X j.fst.fst).f j.fst.snd ≫ pullback.snd f (A.𝒰S.f j.fst.fst)) ≫
        (A.𝒰X j.fst.fst).f j.fst.snd ≫ pullback.fst f (A.𝒰S.f j.fst.fst)
H₂ :
  pullback.fst (D.map A.hii' ≫ pullback.lift A.a A.b ⋯)
        ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
      D.map A.hii' ≫ A.b =
    pullback.snd (D.map A.hii' ≫ pullback.lift A.a A.b ⋯)
        ((Scheme.Pullback.diagonalCover f A.𝒰S A.𝒰X).f ⟨j.fst.fst, (j.fst.snd, j.fst.snd)⟩) ≫
      pullback.snd ((A.𝒰X j.fst.fst).f j.fst.snd ≫ pullback.snd f (A.𝒰S.f j.fst.fst))
          ((A.𝒰X j.fst.fst).f j.fst.snd ≫ pullback.snd f (A.𝒰S.f j.fst.fst)) ≫
        (A.𝒰X j.fst.fst).f j.fst.snd ≫ pullback.fst f (A.𝒰S.f j.fst.fst)
⊢ ∃ k hki',
    (Precoverage.ZeroHypercover.pullback₁ (D.map hki') A.𝒰D).f j ≫ D.map (hki' ≫ A.hii') ≫ A.a =
      (Precoverage.ZeroHypercover.pullback₁ (D.map hki') A.𝒰D).f j ≫ D.map (hki' ≫ A.hii') ≫ A.b