Module: Mathlib.AlgebraicGeometry.Group.Abelian

Goal state before:
pp: K : Type u
inst✝⁴ : Field K
inst✝³ : IsAlgClosed K
G : Over (Spec (CommRingCat.of K))
inst✝² : IsProper G.hom
inst✝¹ : IsIntegral (G ⊗ G).left
inst✝ : GrpObj G
S : Scheme := Spec (CommRingCat.of K)
point : ↥S := IsLocalRing.closedPoint K
hpoint : IsClosed {point}
this✝¹⁰ : Nonempty ↥G.left
this✝⁹ : IsProper (G ⊗ G).hom
this✝⁸ : JacobsonSpace ↥(G ⊗ G).left
this✝⁷ : Surjective G.hom
this✝⁶ : IsProper (Over.Hom.left (fst G G))
this✝⁵ : Surjective (Over.Hom.left (fst G G))
this✝⁴ : IsProper (Over.Hom.left (GrpObj.commutator G) ≫ G.hom)
this✝³ : IsClosedImmersion (Over.Hom.left (lift η η) ≫ Over.Hom.left (fst G G))
this✝² : IsClosedImmersion (Over.Hom.left (lift η η))
γ : G ⊗ G ⟶ G ⊗ G := lift (fst G G) (GrpObj.commutator G)
this✝¹ : IsProper (Over.Hom.left γ ≫ Over.Hom.left (fst G G))
this✝ : IsProper (Over.Hom.left γ)
H :
  (⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point} \
      ⇑(Over.Hom.left γ) ⁻¹' {(Over.Hom.left (lift η η)) point}).Nonempty
c : Spec (CommRingCat.of K) ⟶ (G ⊗ G).left
hc : c ≫ (G ⊗ G).hom = 𝟙 (Spec (CommRingCat.of K))
hc₃ : c point ∈ closedPoints ↥(G ⊗ G).left
hc₁ : c point ∈ ⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point}
hc₂ : c point ∉ ⇑(Over.Hom.left γ) ⁻¹' {(Over.Hom.left (lift η η)) point}
e : (pointEquivClosedPoint (G ⊗ G).hom) ⟨c, hc⟩ = ⟨c point, hc₃⟩
fc : 𝟙_ (Over S) ⟶ 𝟙_ (Over S) ⊗ G := lift (𝟙 (𝟙_ (Over S))) (Over.homMk c hc ≫ snd G G)
this : c ≫ pullback.fst G.hom G.hom = Over.Hom.left η
H₁ : c = Over.Hom.left fc ≫ Over.Hom.left (η ▷ G)
⊢ fc ≫ η ▷ G ≫ γ = lift η η

Tactic:
ext1

Goal state after:
case h_fst
K : Type u
inst✝⁴ : Field K
inst✝³ : IsAlgClosed K
G : Over (Spec (CommRingCat.of K))
inst✝² : IsProper G.hom
inst✝¹ : IsIntegral (G ⊗ G).left
inst✝ : GrpObj G
S : Scheme := ⋯
point : ↥S := ⋯
hpoint : IsClosed {point}
this✝¹⁰ : Nonempty ↥G.left
this✝⁹ : IsProper (G ⊗ G).hom
this✝⁸ : JacobsonSpace ↥(G ⊗ G).left
this✝⁷ : Surjective G.hom
this✝⁶ : IsProper (Over.Hom.left (fst G G))
this✝⁵ : Surjective (Over.Hom.left (fst G G))
this✝⁴ : IsProper (Over.Hom.left (GrpObj.commutator G) ≫ G.hom)
this✝³ : IsClosedImmersion (Over.Hom.left (lift η η) ≫ Over.Hom.left (fst G G))
this✝² : IsClosedImmersion (Over.Hom.left (lift η η))
γ : G ⊗ G ⟶ G ⊗ G := ⋯
this✝¹ : IsProper (Over.Hom.left γ ≫ Over.Hom.left (fst G G))
this✝ : IsProper (Over.Hom.left γ)
H :
  (⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point} \
      ⇑(Over.Hom.left γ) ⁻¹' {(Over.Hom.left (lift η η)) point}).Nonempty
c : Spec (CommRingCat.of K) ⟶ (G ⊗ G).left
hc : c ≫ (G ⊗ G).hom = 𝟙 (Spec (CommRingCat.of K))
hc₃ : c point ∈ closedPoints ↥(G ⊗ G).left
hc₁ : c point ∈ ⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point}
hc₂ : c point ∉ ⇑(Over.Hom.left γ) ⁻¹' {(Over.Hom.left (lift η η)) point}
e : (pointEquivClosedPoint (G ⊗ G).hom) ⟨c, hc⟩ = ⟨c point, hc₃⟩
fc : 𝟙_ (Over S) ⟶ 𝟙_ (Over S) ⊗ G := ⋯
this : c ≫ pullback.fst G.hom G.hom = Over.Hom.left η
H₁ : c = Over.Hom.left fc ≫ Over.Hom.left (η ▷ G)
⊢ (fc ≫ η ▷ G ≫ γ) ≫ fst G G = lift η η ≫ fst G G

case h_snd
K : Type u
inst✝⁴ : Field K
inst✝³ : IsAlgClosed K
G : Over (Spec (CommRingCat.of K))
inst✝² : IsProper G.hom
inst✝¹ : IsIntegral (G ⊗ G).left
inst✝ : GrpObj G
S : Scheme := ⋯
point : ↥S := ⋯
hpoint : IsClosed {point}
this✝¹⁰ : Nonempty ↥G.left
this✝⁹ : IsProper (G ⊗ G).hom
this✝⁸ : JacobsonSpace ↥(G ⊗ G).left
this✝⁷ : Surjective G.hom
this✝⁶ : IsProper (Over.Hom.left (fst G G))
this✝⁵ : Surjective (Over.Hom.left (fst G G))
this✝⁴ : IsProper (Over.Hom.left (GrpObj.commutator G) ≫ G.hom)
this✝³ : IsClosedImmersion (Over.Hom.left (lift η η) ≫ Over.Hom.left (fst G G))
this✝² : IsClosedImmersion (Over.Hom.left (lift η η))
γ : G ⊗ G ⟶ G ⊗ G := ⋯
this✝¹ : IsProper (Over.Hom.left γ ≫ Over.Hom.left (fst G G))
this✝ : IsProper (Over.Hom.left γ)
H :
  (⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point} \
      ⇑(Over.Hom.left γ) ⁻¹' {(Over.Hom.left (lift η η)) point}).Nonempty
c : Spec (CommRingCat.of K) ⟶ (G ⊗ G).left
hc : c ≫ (G ⊗ G).hom = 𝟙 (Spec (CommRingCat.of K))
hc₃ : c point ∈ closedPoints ↥(G ⊗ G).left
hc₁ : c point ∈ ⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point}
hc₂ : c point ∉ ⇑(Over.Hom.left γ) ⁻¹' {(Over.Hom.left (lift η η)) point}
e : (pointEquivClosedPoint (G ⊗ G).hom) ⟨c, hc⟩ = ⟨c point, hc₃⟩
fc : 𝟙_ (Over S) ⟶ 𝟙_ (Over S) ⊗ G := ⋯
this : c ≫ pullback.fst G.hom G.hom = Over.Hom.left η
H₁ : c = Over.Hom.left fc ≫ Over.Hom.left (η ▷ G)
⊢ (fc ≫ η ▷ G ≫ γ) ≫ snd G G = lift η η ≫ snd G G