mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
p q : Submodule A M
h : p ⋖ q
f : ↥p →ₗ[A] ↥q := inclusion ⋯
key : IsSimpleModule A (↥q ⧸ f.range)
hm : (maximalIdeal A).IsMaximal
e : (↥q ⧸ f.range) ≃ₗ[A] A ⧸ maximalIdeal A
g : ↥q →ₗ[A] A ⧸ maximalIdeal A := ↑e ∘ₗ f.range.mkQ
this✝ : Function.Injective ⇑f
this : Function.Surjective ⇑g
⊢ g.ker = f.range

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing T
inst✝⁴ : Algebra R S
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
q : Ideal S
r : Ideal T
inst✝ : r.LiesOver q
⊢ r.inertiaDeg R = q.inertiaDeg R * r.inertiaDeg S

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing T
inst✝⁴ : Algebra R S
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
q : Ideal S
r : Ideal T
inst✝ : r.LiesOver q
⊢ q.inertiaDeg R ∣ r.inertiaDeg R

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : CommRing T
inst✝⁴ : Algebra R S
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
q : Ideal S
r : Ideal T
inst✝ : r.LiesOver q
⊢ r.inertiaDeg S ∣ r.inertiaDeg R

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
p q : Submodule A M
h : p ⋖ q
f : ↥p →ₗ[A] ↥q := inclusion ⋯
key : IsSimpleModule A (↥q ⧸ f.range)
hm : (maximalIdeal A).IsMaximal
e : (↥q ⧸ f.range) ≃ₗ[A] A ⧸ maximalIdeal A
g : ↥q →ₗ[A] A ⧸ maximalIdeal A := ↑e ∘ₗ f.range.mkQ
this✝² : Function.Injective ⇑f
this✝¹ : Function.Surjective ⇑g
this✝ : Function.Exact ⇑f ⇑g
this : FaithfullyFlat A B
⊢ Function.Injective ⇑((AlgebraTensorModule.lTensor B B) f)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
p q : Submodule A M
h : p ⋖ q
f : ↥p →ₗ[A] ↥q := inclusion ⋯
key : IsSimpleModule A (↥q ⧸ f.range)
hm : (maximalIdeal A).IsMaximal
e : (↥q ⧸ f.range) ≃ₗ[A] A ⧸ maximalIdeal A
g : ↥q →ₗ[A] A ⧸ maximalIdeal A := ↑e ∘ₗ f.range.mkQ
this✝² : Function.Injective ⇑f
this✝¹ : Function.Surjective ⇑g
this✝ : Function.Exact ⇑f ⇑g
this : FaithfullyFlat A B
⊢ Function.Surjective ⇑((AlgebraTensorModule.lTensor B B) g)

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : DecidablePred fun n ↦ ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
h : ∃ n, ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
⊢ p.ramificationIdx' P = Nat.find h

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
p q : Submodule A M
h : p ⋖ q
f : ↥p →ₗ[A] ↥q := inclusion ⋯
key : IsSimpleModule A (↥q ⧸ f.range)
hm : (maximalIdeal A).IsMaximal
e : (↥q ⧸ f.range) ≃ₗ[A] A ⧸ maximalIdeal A
g : ↥q →ₗ[A] A ⧸ maximalIdeal A := ↑e ∘ₗ f.range.mkQ
this✝² : Function.Injective ⇑f
this✝¹ : Function.Surjective ⇑g
this✝ : Function.Exact ⇑f ⇑g
this : FaithfullyFlat A B
⊢ Function.Exact ⇑((AlgebraTensorModule.lTensor B B) f) ⇑((AlgebraTensorModule.lTensor B B) g)

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
h : ∀ (n : ℕ), ∃ k, map f p ≤ P ^ k ∧ n < k
⊢ ¬∃ n, ∀ a ∈ {n | map f p ≤ P ^ n}, a ≤ n

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
q : Ideal S
G : Type u_4
inst✝² : Group G
inst✝¹ : MulSemiringAction G S
inst✝ : SMulCommClass G R S
g : G
⊢ (g • q).inertiaDeg R = q.inertiaDeg R

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
p : Ideal R
q : Ideal S
inst✝³ : Module.Finite R S
inst✝² : p.IsMaximal
inst✝¹ : q.IsMaximal
inst✝ : q.LiesOver p
⊢ Submodule.cardQuot p ^ q.inertiaDeg R = Submodule.cardQuot q

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
n : ℕ
hle : map f p ≤ P ^ n
hgt : ¬map f p ≤ P ^ (n + 1)
Q : ℕ → Prop := fun m ↦ ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ m
⊢ Q n

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
n : ℕ
hle : map f p ≤ P ^ n
hgt : ¬map f p ≤ P ^ (n + 1)
⊢ p.ramificationIdx' P = n

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : Algebra R S
p : Ideal R
q : Ideal S
inst✝⁶ : Module.Finite R S
inst✝⁵ : q.IsPrime
inst✝⁴ : q.LiesOver p
inst✝³ : IsDedekindDomain R
inst✝² : IsDedekindDomain S
inst✝¹ : Module.Free ℤ R
inst✝ : Module.Free ℤ S
⊢ absNorm p ^ q.inertiaDeg R = absNorm q

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: R : Type u_1
inst✝⁵ : CommRing R
inst✝⁴ : IsDedekindDomain R
inst✝³ : Module.Free ℤ R
inst✝² : Module.Finite ℤ R
p : ℤ
P : Ideal R
inst✝¹ : P.IsPrime
inst✝ : P.LiesOver (span {p})
⊢ p.natAbs ^ P.inertiaDeg ℤ = absNorm P

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
n : ℕ
hgt : ¬map f p ≤ P ^ (n + 1)
⊢ ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
p q : Submodule A M
h : p ⋖ q
⊢ length B ↥(Submodule.baseChange B q) =
    length B ↥(Submodule.baseChange B p) + length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A))

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
n : ℕ
hgt : ¬map f p ≤ P ^ n
⊢ p.ramificationIdx' P < n

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
P : Ideal S
n : ℕ
hn : ∀ a ∈ {n | map f ⊥ ≤ P ^ n}, a ≤ n
⊢ n.succ ∈ {n | map f ⊥ ≤ P ^ n}

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
h : ¬map f p ≤ P
⊢ map f p ≤ P ^ 0

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
h : ¬map f p ≤ P
⊢ ¬map f p ≤ P ^ (0 + 1)

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
e : ℕ
he : e ≠ 0
hle : map f p ≤ P ^ e
hnle : ¬map f p ≤ P ^ (e + 1)
⊢ p.ramificationIdx' P ≠ 0

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
n : ℕ
hn : n ≤ p.ramificationIdx' P
⊢ map f p ≤ P ^ n

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
h : IsFiniteLength A M
s : CompositionSeries (Submodule A M)
hs_bot : RelSeries.head s = ⊥
hs_top : RelSeries.last s = ⊤
this :
  ∀ (k : Fin (s.length + 1)),
    length B ↥(Submodule.baseChange B (s.toFun k)) = ↑↑k * length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A))
⊢ length B (B ⊗[A] M) = ↑s.length * length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A))

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁴ : CommRing R
S : Type v
inst✝³ : CommRing S
inst✝² : Algebra R S
p : Ideal R
S₁ : Type u_1
inst✝¹ : CommRing S₁
inst✝ : Algebra R S₁
e : S ≃ₐ[R] S₁
P : Ideal S₁
⊢ p.ramificationIdx' (comap e P) = p.ramificationIdx' P

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁶ : CommRing R
S : Type v
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
p : Ideal R
S₁ : Type u_1
inst✝³ : CommRing S₁
inst✝² : Algebra R S₁
E : Type u_2
inst✝¹ : EquivLike E S S₁
inst✝ : AlgEquivClass E R S S₁
P : Ideal S
e : E
⊢ p.ramificationIdx' (map e P) = p.ramificationIdx' P

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
hp : map f p ≤ P
H : ∃ n, ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
he : Nat.find H ≠ 1
⊢ map f p ≤ P ^ 1

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
hp : map f p ≤ P
H : ∃ n, ∀ (k : ℕ), map f p ≤ P ^ k → k ≤ n
he : Nat.find H ≠ 1
this : 1 ≤ Nat.find H
⊢ 1 < Nat.find H

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
h : ¬IsFiniteLength A M
⊢ ¬IsFiniteLength B (B ⊗[A] M)

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
h : length A M = ⊤
this : length B (B ⊗[A] M) = ⊤
⊢ length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A)) ≠ 0

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝² : CommRing R
S : Type v
inst✝¹ : CommRing S
inst✝ : Algebra R S
p : Ideal R
P : Ideal S
hp : map f p ≤ P
⊢ p.ramificationIdx' P ≠ 1 ↔ map f p ≤ P ^ 2

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.ResidueField.Instances

Goal state before:
pp: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹² : CommRing R
inst✝¹¹ : CommRing A
inst✝¹⁰ : CommRing B
inst✝⁹ : Algebra R A
inst✝⁸ : Algebra A B
inst✝⁷ : Algebra R B
inst✝⁶ : IsScalarTower R A B
p : Ideal A
q : Ideal B
inst✝⁵ : q.LiesOver p
inst✝⁴ : p.IsMaximal
inst✝³ : q.IsMaximal
inst✝² : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝¹ : Localization.AtPrime.IsLiesOverAlgebra p q
inst✝ : Algebra.IsSeparable (A ⧸ p) (B ⧸ q)
⊢ Algebra.IsSeparable p.ResidueField q.ResidueField

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁸ : CommRing A
inst✝⁷ : CommRing B
inst✝⁶ : IsLocalRing A
inst✝⁵ : IsLocalRing B
inst✝⁴ : Algebra A B
inst✝³ : IsLocalHom (algebraMap A B)
inst✝² : AddCommGroup M
inst✝¹ : Module A M
inst✝ : Flat A B
⊢ length B (B ⊗[A] M) = length A M * length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A))

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Ideal.IdempotentFG

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
I : Ideal R
h : I.FG
e : IsIdempotentElem I
⊢ I ≤ I • I

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Ideal.IdempotentFG

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
I : Ideal R
h : I.FG
⊢ IsIdempotentElem I ↔ ∃ e, IsIdempotentElem e ∧ I = R ∙ e

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.Ideal.IdempotentFG

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
inst✝ : IsDomain R
I : Ideal R
h : I.FG
⊢ IsIdempotentElem I ↔ I = ⊥ ∨ I = ⊤

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.ResidueField.Instances

Goal state before:
pp: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹² : CommRing R
inst✝¹¹ : CommRing A
inst✝¹⁰ : CommRing B
inst✝⁹ : Algebra R A
inst✝⁸ : Algebra A B
inst✝⁷ : Algebra R B
inst✝⁶ : IsScalarTower R A B
p : Ideal A
q : Ideal B
inst✝⁵ : q.LiesOver p
inst✝⁴ : p.IsMaximal
inst✝³ : q.IsMaximal
inst✝² : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝¹ : Localization.AtPrime.IsLiesOverAlgebra p q
inst✝ : Algebra.IsSeparable p.ResidueField q.ResidueField
⊢ Algebra.IsSeparable (A ⧸ p) (B ⧸ q)

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁴ : CommRing R
S : Type v
inst✝³ : CommRing S
inst✝² : Algebra R S
p : Ideal R
P : Ideal S
inst✝¹ : P.IsPrime
inst✝ : IsNoetherianRing S
hpP : map f p ≤ P
hp : P ≠ ⊥
hp' : P.primeCompl ≤ nonZeroDivisors S
H : map (algebraMap R (Localization.AtPrime P)) p = maximalIdeal (Localization.AtPrime P)
⊢ p.ramificationIdx' P = 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.ResidueField.Instances

Goal state before:
pp: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹² : CommRing R
inst✝¹¹ : CommRing A
inst✝¹⁰ : CommRing B
inst✝⁹ : Algebra R A
inst✝⁸ : Algebra A B
inst✝⁷ : Algebra R B
inst✝⁶ : IsScalarTower R A B
p : Ideal A
q : Ideal B
inst✝⁵ : q.LiesOver p
inst✝⁴ : p.IsPrime
inst✝³ : q.IsPrime
inst✝² : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝¹ : Localization.AtPrime.IsLiesOverAlgebra p q
inst✝ : Algebra.IsIntegral A B
this✝² : Algebra.IsIntegral (A ⧸ p) (B ⧸ q)
this✝¹ : Algebra (A ⧸ p) q.ResidueField :=
  ((algebraMap (B ⧸ q) q.ResidueField).comp (algebraMap (A ⧸ p) (B ⧸ q))).toAlgebra
this✝ : IsScalarTower (A ⧸ p) (B ⧸ q) q.ResidueField
this : Algebra.IsAlgebraic (A ⧸ p) q.ResidueField
⊢ IsScalarTower (A ⧸ p) p.ResidueField q.ResidueField

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
inst✝ : IsDedekindDomain S
h₁ : map f p ≠ ⊤
h₂ : map f p ≠ ⊥
⊢ map f p ≤ map f p ^ 1

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
inst✝ : IsDedekindDomain S
h₁ : map f p ≠ ⊤
h₂ : map f p ≠ ⊥
h : map f p ≤ map f p ^ (1 + 1)
⊢ map f p ^ 1 = map f p ^ 2

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.ResidueField.Instances

Goal state before:
pp: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹² : CommRing R
inst✝¹¹ : CommRing A
inst✝¹⁰ : CommRing B
inst✝⁹ : Algebra R A
inst✝⁸ : Algebra A B
inst✝⁷ : Algebra R B
inst✝⁶ : IsScalarTower R A B
p : Ideal A
q : Ideal B
inst✝⁵ : q.LiesOver p
inst✝⁴ : p.IsPrime
inst✝³ : q.IsPrime
inst✝² : Algebra (Localization.AtPrime p) (Localization.AtPrime q)
inst✝¹ : Localization.AtPrime.IsLiesOverAlgebra p q
inst✝ : Algebra.IsIntegral A B
⊢ Algebra.IsAlgebraic p.ResidueField q.ResidueField

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
inst✝ : IsDedekindDomain S
h₁ : map f p ≠ ⊤
h₂ : map f p ≠ ⊥
h : map f p ≤ map f p ^ (1 + 1)
this : map f p ^ 1 = map f p ^ 2
⊢ map f p ≠ 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.ResidueField.Instances

Goal state before:
pp: R✝ : Type u_1
A : Type u_2
B : Type u_3
inst✝¹² : CommRing R✝
inst✝¹¹ : CommRing A
inst✝¹⁰ : CommRing B
inst✝⁹ : Algebra R✝ A
inst✝⁸ : Algebra A B
inst✝⁷ : Algebra R✝ B
inst✝⁶ : IsScalarTower R✝ A B
p : Ideal A
q : Ideal B
inst✝⁵ : q.LiesOver p
R : Type u_4
k : Type u_5
inst✝⁴ : CommRing R
inst✝³ : IsLocalRing R
inst✝² : Field k
inst✝¹ : Algebra R k
inst✝ : Algebra.IsIntegral R k
⊢ ∀ a ∈ maximalIdeal R, (algebraMap R k) a = 0

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
inst✝ : IsDedekindDomain S
h₁ : map f p ≠ ⊤
h₂ : map f p ≠ ⊥
⊢ p.ramificationIdx' (map f p) = 1

Tactic:
by

Goal state after:
Module: Mathlib.RingTheory.LocalRing.ResidueField.Instances

Goal state before:
pp: R✝ : Type u_1
A : Type u_2
B : Type u_3
inst✝¹² : CommRing R✝
inst✝¹¹ : CommRing A
inst✝¹⁰ : CommRing B
inst✝⁹ : Algebra R✝ A
inst✝⁸ : Algebra A B
inst✝⁷ : Algebra R✝ B
inst✝⁶ : IsScalarTower R✝ A B
p : Ideal A
q : Ideal B
inst✝⁵ : q.LiesOver p
R : Type u_4
k : Type u_5
inst✝⁴ : CommRing R
inst✝³ : IsLocalRing R
inst✝² : Field k
inst✝¹ : Algebra R k
inst✝ : Module.Finite R k
⊢ (algebraMap (ResidueField R) k).comp ↑(Ideal.quotEquivOfEq ⋯) =
    (↑(RingEquiv.quotientBot k)).comp (algebraMap (R ⧸ Ideal.comap (algebraMap R k) ⊥) (k ⧸ ⊥))

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁶ : CommRing R
S : Type v
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
p : Ideal R
P : Ideal S
T : Type u_2
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
Q : Ideal T
hp : p = comap f P
h : ¬sSup {n | map (algebraMap R T) p ≤ Q ^ n} = 0
n : ℕ
hn : n ∈ {n | map (algebraMap S T) P ≤ Q ^ n}
⊢ P ≤ comap (algebraMap S T) (Q ^ n)

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁶ : CommRing R
S : Type v
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
p : Ideal R
P : Ideal S
T : Type u_2
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
Q : Ideal T
hp : p = comap f P
h : p.ramificationIdx' Q ≠ 0
⊢ P.ramificationIdx' Q ≤ p.ramificationIdx' Q

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
hP0 : P ≠ ⊥
⊢ p.ramificationIdx' P = Multiset.count P (normalizedFactors (map f p))

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp : map f p ≠ ⊥
hP : P.IsPrime
⊢ p.ramificationIdx' P = multiplicity P (map f p)

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
hP0 : P ≠ ⊥
⊢ p.ramificationIdx' P = Multiset.count P (factors (map f p))

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
le : map f p ≤ P
⊢ P ≠ ⊥

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
S : Type v
inst✝² : CommRing S
inst✝¹ : Algebra R S
p : Ideal R
P : Ideal S
inst✝ : IsDedekindDomain S
hp0 : map f p ≠ ⊥
hP : P.IsPrime
le : map f p ≤ P
⊢ p.ramificationIdx' P ≠ 0

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁴ : CommRing R
S : Type v
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : IsDedekindDomain S
p : Ideal R
P : Ideal S
inst✝ : P.IsPrime
hp : P ≠ ⊥
hpP : map f p ≤ P
⊢ p.ramificationIdx' P = 1 ↔ map (algebraMap R (Localization.AtPrime P)) p = maximalIdeal (Localization.AtPrime P)

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁵ : CommRing R
S : Type v
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
inst✝² : IsDedekindDomain S
inst✝¹ : IsDedekindDomain R
v : Ideal R
w : Ideal S
p : Ideal R
hv : Irreducible v
hp : Prime p
hvp : v ≠ p
inst✝ : w.LiesOver v
⊢ emultiplicity w (map f p) = 0

Tactic:
by

Goal state after:
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁶ : CommRing R
S : Type v
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
inst✝³ : IsDedekindDomain S
inst✝² : IsDedekindDomain R
inst✝¹ : FaithfulSMul R S
v : Ideal R
w : Ideal S
p : Ideal R
hv : Irreducible v
hp : Prime p
hw : Irreducible w
hw_bot : w ≠ ⊥
inst✝ : w.LiesOver v
⊢ emultiplicity w (map f p) = ↑(v.ramificationIdx' w) * emultiplicity v p

Tactic:
have hp_bot : p.map (algebraMap R S) ≠ ⊥ := map_ne_bot_of_ne_bot hp.ne_zero

Goal state after:
R : Type u
inst✝⁶ : CommRing R
S : Type v
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
inst✝³ : IsDedekindDomain S
inst✝² : IsDedekindDomain R
inst✝¹ : FaithfulSMul R S
v : Ideal R
w : Ideal S
p : Ideal R
hv : Irreducible v
hp : Prime p
hw : Irreducible w
hw_bot : w ≠ ⊥
inst✝ : w.LiesOver v
hp_bot : map f p ≠ ⊥
⊢ emultiplicity w (map f p) = ↑(v.ramificationIdx' w) * emultiplicity v p
Module: Mathlib.NumberTheory.RamificationInertia.Ramification

Goal state before:
pp: R : Type u
inst✝⁶ : CommRing R
S : Type v
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
inst✝³ : IsDedekindDomain S
inst✝² : IsDedekindDomain R
inst✝¹ : FaithfulSMul R S
v : Ideal R
w : Ideal S
p : Ideal R
hv : Irreducible v
hp : Prime p
hw : Irreducible w
hw_bot : w ≠ ⊥
inst✝ : w.LiesOver v
⊢ emultiplicity w (map f p) = ↑(v.ramificationIdx' w) * emultiplicity v p

Tactic:
by

Goal state after: