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✝⁹ : Nonempty ↥G.left
this✝⁸ : IsProper (G ⊗ G).hom
this✝⁷ : JacobsonSpace ↥(G ⊗ G).left
this✝⁶ : Surjective G.hom
this✝⁵ : IsProper (Over.Hom.left (fst G G))
this✝⁴ : Surjective (Over.Hom.left (fst G G))
this✝³ : IsProper (Over.Hom.left (GrpObj.commutator G) ≫ G.hom)
this✝² : IsClosedImmersion (Over.Hom.left (lift η η) ≫ Over.Hom.left (fst G G))
this✝¹ : IsClosedImmersion (Over.Hom.left (lift η η))
γ : G ⊗ G ⟶ G ⊗ G := lift (fst G G) (GrpObj.commutator G)
this✝ : IsProper (Over.Hom.left γ ≫ Over.Hom.left (fst G G))
this : IsProper (Over.Hom.left γ)
H✝¹ :
  ⇑(Over.Hom.left γ) '' ⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point} ⊆ {(Over.Hom.left (lift η η)) point}
U : G.left.Opens
hηU : (Over.Hom.left η) point ∈ U
H✝ : IsFinite ((Scheme.Hom.imageι (Over.Hom.left γ) ≫ Over.Hom.left (fst G G)) ∣_ U)
H : ∀ (x : ↥U), (⇑(pullback.fst G.hom G.hom) ⁻¹' {↑x} ∩ Set.range ⇑(Over.Hom.left γ)).Finite
⊢ Over.Hom.left (GrpObj.commutator G) = Over.Hom.left (toUnit (G ⊗ G) ≫ η)

Tactic:
refine ext_of_apply_eq G.hom _
    ((fst G G).left ⁻¹ᵁ U).isOpen.isLocallyClosed
    (((fst G G).left ⁻¹ᵁ U).isOpen.dense ?_) ?_ ?_

Goal state after:
case refine_1
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✝⁹ : Nonempty ↥G.left
this✝⁸ : IsProper (G ⊗ G).hom
this✝⁷ : JacobsonSpace ↥(G ⊗ G).left
this✝⁶ : Surjective G.hom
this✝⁵ : IsProper (Over.Hom.left (fst G G))
this✝⁴ : Surjective (Over.Hom.left (fst G G))
this✝³ : IsProper (Over.Hom.left (GrpObj.commutator G) ≫ G.hom)
this✝² : IsClosedImmersion (Over.Hom.left (lift η η) ≫ Over.Hom.left (fst G G))
this✝¹ : IsClosedImmersion (Over.Hom.left (lift η η))
γ : G ⊗ G ⟶ G ⊗ G := lift (fst G G) (GrpObj.commutator G)
this✝ : IsProper (Over.Hom.left γ ≫ Over.Hom.left (fst G G))
this : IsProper (Over.Hom.left γ)
H✝¹ :
  ⇑(Over.Hom.left γ) '' ⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point} ⊆ {(Over.Hom.left (lift η η)) point}
U : G.left.Opens
hηU : (Over.Hom.left η) point ∈ U
H✝ : IsFinite ((Scheme.Hom.imageι (Over.Hom.left γ) ≫ Over.Hom.left (fst G G)) ∣_ U)
H : ∀ (x : ↥U), (⇑(pullback.fst G.hom G.hom) ⁻¹' {↑x} ∩ Set.range ⇑(Over.Hom.left γ)).Finite
⊢ (↑(Over.Hom.left (fst G G) ⁻¹ᵁ U)).Nonempty

case refine_2
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✝⁹ : Nonempty ↥G.left
this✝⁸ : IsProper (G ⊗ G).hom
this✝⁷ : JacobsonSpace ↥(G ⊗ G).left
this✝⁶ : Surjective G.hom
this✝⁵ : IsProper (Over.Hom.left (fst G G))
this✝⁴ : Surjective (Over.Hom.left (fst G G))
this✝³ : IsProper (Over.Hom.left (GrpObj.commutator G) ≫ G.hom)
this✝² : IsClosedImmersion (Over.Hom.left (lift η η) ≫ Over.Hom.left (fst G G))
this✝¹ : IsClosedImmersion (Over.Hom.left (lift η η))
γ : G ⊗ G ⟶ G ⊗ G := lift (fst G G) (GrpObj.commutator G)
this✝ : IsProper (Over.Hom.left γ ≫ Over.Hom.left (fst G G))
this : IsProper (Over.Hom.left γ)
H✝¹ :
  ⇑(Over.Hom.left γ) '' ⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point} ⊆ {(Over.Hom.left (lift η η)) point}
U : G.left.Opens
hηU : (Over.Hom.left η) point ∈ U
H✝ : IsFinite ((Scheme.Hom.imageι (Over.Hom.left γ) ≫ Over.Hom.left (fst G G)) ∣_ U)
H : ∀ (x : ↥U), (⇑(pullback.fst G.hom G.hom) ⁻¹' {↑x} ∩ Set.range ⇑(Over.Hom.left γ)).Finite
⊢ ∀ x ∈ ↑(Over.Hom.left (fst G G) ⁻¹ᵁ U),
    IsClosed {x} → (Over.Hom.left (GrpObj.commutator G)) x = (Over.Hom.left (toUnit (G ⊗ G) ≫ η)) x

case refine_3
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✝⁹ : Nonempty ↥G.left
this✝⁸ : IsProper (G ⊗ G).hom
this✝⁷ : JacobsonSpace ↥(G ⊗ G).left
this✝⁶ : Surjective G.hom
this✝⁵ : IsProper (Over.Hom.left (fst G G))
this✝⁴ : Surjective (Over.Hom.left (fst G G))
this✝³ : IsProper (Over.Hom.left (GrpObj.commutator G) ≫ G.hom)
this✝² : IsClosedImmersion (Over.Hom.left (lift η η) ≫ Over.Hom.left (fst G G))
this✝¹ : IsClosedImmersion (Over.Hom.left (lift η η))
γ : G ⊗ G ⟶ G ⊗ G := lift (fst G G) (GrpObj.commutator G)
this✝ : IsProper (Over.Hom.left γ ≫ Over.Hom.left (fst G G))
this : IsProper (Over.Hom.left γ)
H✝¹ :
  ⇑(Over.Hom.left γ) '' ⇑(Over.Hom.left (fst G G)) ⁻¹' {(Over.Hom.left η) point} ⊆ {(Over.Hom.left (lift η η)) point}
U : G.left.Opens
hηU : (Over.Hom.left η) point ∈ U
H✝ : IsFinite ((Scheme.Hom.imageι (Over.Hom.left γ) ≫ Over.Hom.left (fst G G)) ∣_ U)
H : ∀ (x : ↥U), (⇑(pullback.fst G.hom G.hom) ⁻¹' {↑x} ∩ Set.range ⇑(Over.Hom.left γ)).Finite
⊢ Over.Hom.left (GrpObj.commutator G) ≫ G.hom = Over.Hom.left (toUnit (G ⊗ G) ≫ η) ≫ G.hom