Theorem: Ideal.MvPolynomial.aux_IH
File: Mathlib/RingTheory/Jacobson.lean

tactic: let Q := P.comap v.toAlgHom.toRingHom
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
⊢ (algebraMap R (T ⧸ P)).IsIntegral

tactic: have hw : Ideal.map v Q = P := map_comap_of_surjective v v.surjective P
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
⊢ (algebraMap R (T ⧸ P)).IsIntegral

tactic: haveI hQ : IsMaximal Q := comap_isMaximal_of_surjective _ v.surjective
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
⊢ (algebraMap R (T ⧸ P)).IsIntegral

tactic: let w : (S[X] ⧸ Q) ≃ₐ[R] (T ⧸ P) := Ideal.quotientEquivAlg Q P v hw.symm
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
⊢ (algebraMap R (T ⧸ P)).IsIntegral

tactic: let Q' := Q.comap (Polynomial.C)
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
⊢ (algebraMap R (T ⧸ P)).IsIntegral

tactic: let w' : (S ⧸ Q') →ₐ[R] (S[X] ⧸ Q) := Ideal.quotientMapₐ Q (Cₐ R S) le_rfl
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
⊢ (algebraMap R (T ⧸ P)).IsIntegral

tactic: have h_eq : algebraMap R (T ⧸ P) =
  w.toRingEquiv.toRingHom.comp (w'.toRingHom.comp (algebraMap R (S ⧸ Q'))) := by
  ext r
  simp only [AlgEquiv.toAlgHom_eq_coe, AlgHom.toRingHom_eq_coe, AlgEquiv.toRingEquiv_eq_coe,
    RingEquiv.toRingHom_eq_coe, AlgHom.comp_algebraMap_of_tower, coe_comp, coe_coe,
    AlgEquiv.coe_ringEquiv, Function.comp_apply, AlgEquiv.commutes]
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (algebraMap R (T ⧸ P)).IsIntegral

tactic: rw [h_eq]
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (algebraMap R (T ⧸ P)).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))).IsIntegral

tactic: apply RingHom.IsIntegral.trans
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))).IsIntegral
state_after: case hf
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (w'.comp (algebraMap R (S ⧸ Q'))).IsIntegral

case hg
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ w.toRingEquiv.toRingHom.IsIntegral

tactic: ext r
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
⊢ algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
state_after: case a
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
r : R
⊢ (algebraMap R (T ⧸ P)) r = (w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))) r

tactic: simp only [AlgEquiv.toAlgHom_eq_coe, AlgHom.toRingHom_eq_coe, AlgEquiv.toRingEquiv_eq_coe,
  RingEquiv.toRingHom_eq_coe, AlgHom.comp_algebraMap_of_tower, coe_comp, coe_coe,
  AlgEquiv.coe_ringEquiv, Function.comp_apply, AlgEquiv.commutes]
state_before: case a
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
r : R
⊢ (algebraMap R (T ⧸ P)) r = (w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))) r
state_after: no goals

tactic: apply RingHom.IsIntegral.trans
state_before: case hf
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (w'.comp (algebraMap R (S ⧸ Q'))).IsIntegral
state_after: case hf.hf
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (algebraMap R (S ⧸ Q')).IsIntegral

case hf.hg
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ w'.IsIntegral

tactic: apply IH
state_before: case hf.hf
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ (algebraMap R (S ⧸ Q')).IsIntegral
state_after: case hf.hf.a
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ Q'.IsMaximal

tactic: apply Polynomial.isMaximal_comap_C_of_isJacobson'
state_before: case hf.hf.a
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ Q'.IsMaximal
state_after: case hf.hf.a.hP
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ Q.IsMaximal

tactic: exact hQ
state_before: case hf.hf.a.hP
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ Q.IsMaximal
state_after: no goals

tactic: suffices w'.toRingHom = Ideal.quotientMap Q (Polynomial.C) le_rfl by
  rw [this]
  rw [isIntegral_quotientMap_iff _]
  apply Polynomial.quotient_mk_comp_C_isIntegral_of_jacobson
state_before: case hf.hg
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ w'.IsIntegral
state_after: case hf.hg
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ w'.toRingHom = quotientMap Q Polynomial.C ⋯

tactic: rfl
state_before: case hf.hg
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ w'.toRingHom = quotientMap Q Polynomial.C ⋯
state_after: no goals

tactic: rw [this]
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
this : w'.toRingHom = quotientMap Q Polynomial.C ⋯
⊢ w'.IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
this : w'.toRingHom = quotientMap Q Polynomial.C ⋯
⊢ (quotientMap Q Polynomial.C ⋯).IsIntegral

tactic: rw [isIntegral_quotientMap_iff _]
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
this : w'.toRingHom = quotientMap Q Polynomial.C ⋯
⊢ (quotientMap Q Polynomial.C ⋯).IsIntegral
state_after: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
this : w'.toRingHom = quotientMap Q Polynomial.C ⋯
⊢ ((Quotient.mk Q).comp Polynomial.C).IsIntegral

tactic: apply Polynomial.quotient_mk_comp_C_isIntegral_of_jacobson
state_before: n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
this : w'.toRingHom = quotientMap Q Polynomial.C ⋯
⊢ ((Quotient.mk Q).comp Polynomial.C).IsIntegral
state_after: no goals

tactic: apply RingHom.isIntegral_of_surjective
state_before: case hg
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ w.toRingEquiv.toRingHom.IsIntegral
state_after: case hg.hf
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ Function.Surjective ⇑w.toRingEquiv.toRingHom

tactic: exact w.surjective
state_before: case hg.hf
n : ℕ
R : Type u
S : Type v
T : Type w
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : IsJacobson S
inst✝¹ : Algebra R S
inst✝ : Algebra R T
IH : ∀ (Q : Ideal S), Q.IsMaximal → (algebraMap R (S ⧸ Q)).IsIntegral
v : S[X] ≃ₐ[R] T
P : Ideal T
hP : P.IsMaximal
Q : Ideal S[X] := comap (↑v).toRingHom P
hw : map v Q = P
hQ : Q.IsMaximal
w : (S[X] ⧸ Q) ≃ₐ[R] T ⧸ P := Q.quotientEquivAlg P v ⋯
Q' : Ideal S := comap Polynomial.C Q
w' : S ⧸ Q' →ₐ[R] S[X] ⧸ Q := quotientMapₐ Q (Ideal.MvPolynomial.Cₐ R S) ⋯
h_eq : algebraMap R (T ⧸ P) = w.toRingEquiv.toRingHom.comp (w'.comp (algebraMap R (S ⧸ Q')))
⊢ Function.Surjective ⇑w.toRingEquiv.toRingHom
state_after: no goals