Module: Mathlib.RingTheory.Extension.Cotangent.Basis

Goal state before:
pp: case e_6
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
ι : Type u_4
P : Generators R S ι
σ : Type u_5
b : Module.Basis σ S P.toExtension.Cotangent
D : Aux P b
inst✝ : Nontrivial S
this : Nontrivial (MvPolynomial ι R ⧸ Ideal.span (Set.range (Subtype.val ∘ D.f ∘ ⇑b)))
⊢ ((localizationAway S D.gbar).ofComp
          (Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x)
              ⋯).toGenerators).toAlgHom
      ((rename Sum.inr)
            ((Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x) ⋯).σ
              D.gbar) *
          X (Sum.inl ()) -
        1) =
    C D.gbar * X () - 1

pp: case e_6.h1
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
ι : Type u_4
P : Generators R S ι
σ : Type u_5
b : Module.Basis σ S P.toExtension.Cotangent
D : Aux P b
inst✝ : Nontrivial S
this : Nontrivial (MvPolynomial ι R ⧸ Ideal.span (Set.range (Subtype.val ∘ D.f ∘ ⇑b)))
⊢ (Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x) ⋯).σ (-1) = -1

pp: case e_6.h0
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
ι : Type u_4
P : Generators R S ι
σ : Type u_5
b : Module.Basis σ S P.toExtension.Cotangent
D : Aux P b
inst✝ : Nontrivial S
this : Nontrivial (MvPolynomial ι R ⧸ Ideal.span (Set.range (Subtype.val ∘ D.f ∘ ⇑b)))
⊢ (Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x) ⋯).σ 0 = 0

Tactic:
]

Goal state after:
case e_6
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
ι : Type u_4
P : Generators R S ι
σ : Type u_5
b : Module.Basis σ S P.toExtension.Cotangent
D : Aux P b
inst✝ : Nontrivial S
this : Nontrivial (MvPolynomial ι R ⧸ Ideal.span (Set.range (Subtype.val ∘ D.f ∘ ⇑b)))
⊢ ((localizationAway S D.gbar).ofComp
          (Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x)
              ⋯).toGenerators).toAlgHom
      ((rename Sum.inr)
            ((Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x) ⋯).σ
              D.gbar) *
          X (Sum.inl ()) -
        1) =
    C D.gbar * X () - 1

case e_6.h1
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
ι : Type u_4
P : Generators R S ι
σ : Type u_5
b : Module.Basis σ S P.toExtension.Cotangent
D : Aux P b
inst✝ : Nontrivial S
this : Nontrivial (MvPolynomial ι R ⧸ Ideal.span (Set.range (Subtype.val ∘ D.f ∘ ⇑b)))
⊢ (Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x) ⋯).σ (-1) = -1

case e_6.h0
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
ι : Type u_4
P : Generators R S ι
σ : Type u_5
b : Module.Basis σ S P.toExtension.Cotangent
D : Aux P b
inst✝ : Nontrivial S
this : Nontrivial (MvPolynomial ι R ⧸ Ideal.span (Set.range (Subtype.val ∘ D.f ∘ ⇑b)))
⊢ (Presentation.naive (fun x ↦ if x = 0 then 0 else if x = -1 then -1 else Function.surjInv ⋯ x) ⋯).σ 0 = 0