mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.DividedPowers.Basic

Goal state before:
pp: A : Type u_1
inst✝ : CommSemiring A
I : Ideal A
a : A
hI : DividedPowers I
ι : Type u_2
s : Finset ι
n : ι → ℕ
ha : a ∈ I
⊢ ∏ i ∈ s, hI.dpow (n i) a = ↑(multinomial s n) * hI.dpow (s.sum n) a

Tactic:
induction s using Finset.induction with
  | empty =>
    simp only [prod_empty, multinomial_empty, cast_one, sum_empty, one_mul]
    rw [hI.dpow_zero ha]
  | insert _ _ hi hrec =>
    rw [prod_insert hi, hrec, ← mul_assoc, mul_comm (hI.dpow (n _) a),
      mul_assoc, hI.mul_dpow ha, ← sum_insert hi, ← mul_assoc]
    apply congr_arg₂ _ _ rfl
    rw [multinomial_insert hi, mul_comm, cast_mul, sum_insert hi]

Goal state after:
Module: Mathlib.RingTheory.Depth.Rees

Goal state before:
pp: R : Type u
inst✝³ : CommRing R
inst✝² : Small.{v, u} R
inst✝¹ : IsNoetherianRing R
I : Ideal R
N : ModuleCat R
Nfin : Module.Finite R ↑N
Nsupp : Module.support R ↑N ⊆ PrimeSpectrum.zeroLocus ↑I
n : ℕ
ih :
  ∀ (M : ModuleCat R) [Module.Finite R ↑M],
    I • ⊤ < ⊤ →
      ∀ (rs : List R),
        (∀ r ∈ rs, r ∈ I) → RingTheory.Sequence.IsRegular (↑M) rs → rs.length = n → ∀ i < n, Subsingleton (Ext N M i)
M : ModuleCat R
inst✝ : Module.Finite R ↑M
smul_lt : I • ⊤ < ⊤
rs : List R
i✝ : ℕ
le_rad : I ≤ (Module.annihilator R ↑N).radical
a : R
rs' : List R
k : ℕ
hk : a ^ k ∈ Module.annihilator R ↑N
reg : IsSMulRegular (↑M) a ∧ RingTheory.Sequence.IsRegular (QuotSMulTop a ↑M) rs'
mem : a ∈ I ∧ ∀ a ∈ rs', a ∈ I
len : rs'.length = n
i : ℕ
hi : i + 1 < n + 1
g : AddCommGrpCat.of (Ext N (M.smulShortComplex a).X₁ (i + 1)) ⟶
  AddCommGrpCat.of (Ext N (M.smulShortComplex a).X₂ (i + 1)) :=
  AddCommGrpCat.ofHom ((Ext.mk₀ (M.smulShortComplex a).f).postcomp N ⋯)
⊢ Subsingleton (Ext N (M.smulShortComplex a).X₃ i)

Tactic:
apply ih (ModuleCat.of R (QuotSMulTop a M)) _ rs' mem.2 reg.2 len i (by omega)

Goal state after:
R : Type u
inst✝³ : CommRing R
inst✝² : Small.{v, u} R
inst✝¹ : IsNoetherianRing R
I : Ideal R
N : ModuleCat R
Nfin : Module.Finite R ↑N
Nsupp : Module.support R ↑N ⊆ PrimeSpectrum.zeroLocus ↑I
n : ℕ
ih :
  ∀ (M : ModuleCat R) [Module.Finite R ↑M],
    I • ⊤ < ⊤ →
      ∀ (rs : List R),
        (∀ r ∈ rs, r ∈ I) → RingTheory.Sequence.IsRegular (↑M) rs → rs.length = n → ∀ i < n, Subsingleton (Ext N M i)
M : ModuleCat R
inst✝ : Module.Finite R ↑M
smul_lt : I • ⊤ < ⊤
rs : List R
i✝ : ℕ
le_rad : I ≤ (Module.annihilator R ↑N).radical
a : R
rs' : List R
k : ℕ
hk : a ^ k ∈ Module.annihilator R ↑N
reg : IsSMulRegular (↑M) a ∧ RingTheory.Sequence.IsRegular (QuotSMulTop a ↑M) rs'
mem : a ∈ I ∧ ∀ a ∈ rs', a ∈ I
len : rs'.length = n
i : ℕ
hi : i + 1 < n + 1
g : AddCommGrpCat.of (Ext N (M.smulShortComplex a).X₁ (i + 1)) ⟶
  AddCommGrpCat.of (Ext N (M.smulShortComplex a).X₂ (i + 1)) := ⋯
⊢ I • ⊤ < ⊤
Module: Mathlib.RingTheory.DividedPowerAlgebra.Init

Goal state before:
pp: R : Type u_2
M : Type u_3
inst✝⁴ : CommSemiring R
inst✝³ : AddCommMonoid M
inst✝² : Module R M
A : Type u_4
inst✝¹ : CommSemiring A
inst✝ : Algebra R A
I : Ideal A
hI : DividedPowers I
g : M →ₗ[R] A
hg : ∀ (m : M), g m ∈ I
m : M
⊢ (lift hI g hg) ((embed R M) m) = g m

Tactic:
by
  simp [embed_def, hI.dpow_one (hg m)]

Goal state after:
Module: Mathlib.RingTheory.DividedPowers.RatAlgebra

Goal state before:
pp: case neg
A : Type u_1
inst✝¹ : CommSemiring A
I : Ideal A
inst✝ : DecidablePred fun x ↦ x ∈ I
n : ℕ
hn_fac : IsUnit ↑(n - 1)!
hnI : I ^ n = 0
m : ℕ
x : A
hx : x ∈ I
y : A
hy : y ∈ I
hmn : n ≤ m
h_sub : I ^ m ≤ I ^ n
hxy : (x + y) ^ m = 0
⊢ (↑m !)⁻¹ʳ * (x + y) ^ m =
    ∑ k ∈ Finset.antidiagonal m, (if x ∈ I then (↑k.1!)⁻¹ʳ * x ^ k.1 else 0) * if y ∈ I then (↑k.2!)⁻¹ʳ * y ^ k.2 else 0

Tactic:
rw [hxy, mul_zero, eq_comm]

Goal state after:
case neg
A : Type u_1
inst✝¹ : CommSemiring A
I : Ideal A
inst✝ : DecidablePred fun x ↦ x ∈ I
n : ℕ
hn_fac : IsUnit ↑(n - 1)!
hnI : I ^ n = 0
m : ℕ
x : A
hx : x ∈ I
y : A
hy : y ∈ I
hmn : n ≤ m
h_sub : I ^ m ≤ I ^ n
hxy : (x + y) ^ m = 0
⊢ (∑ k ∈ Finset.antidiagonal m,
      (if x ∈ I then (↑k.1!)⁻¹ʳ * x ^ k.1 else 0) * if y ∈ I then (↑k.2!)⁻¹ʳ * y ^ k.2 else 0) =
    0
Module: Mathlib.RingTheory.TotallySplit

Goal state before:
pp: k : Type u_1
R : Type u_2
S : Type u_3
inst✝⁵ : Field k
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra k R
inst✝¹ : Algebra R S
ι : Type u_4
inst✝ : Finite ι
⊢ ∃ n, Nonempty ((ι → R) ≃ₐ[R] Fin n → R)

Tactic:
cases nonempty_fintype ι

Goal state after:
case intro
k : Type u_1
R : Type u_2
S : Type u_3
inst✝⁵ : Field k
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra k R
inst✝¹ : Algebra R S
ι : Type u_4
inst✝ : Finite ι
val✝ : Fintype ι
⊢ ∃ n, Nonempty ((ι → R) ≃ₐ[R] Fin n → R)
Module: Mathlib.RingTheory.TotallySplit

Goal state before:
pp: case succ.inr
n : ℕ
ih :
  ∀ {R S : Type u} [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : Algebra R S] [Etale R S] [Module.Finite R S],
    Module.rankAtStalk S = ↑n →
      ∃ T x x_1, ∃ (_ : Module.FaithfullyFlat R T) (_ : Module.Finite R T) (_ : Etale R T), IsFiniteSplit T (T ⊗[R] S)
R S : Type u
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : Etale R S
inst✝ : Module.Finite R S
hn : Module.rankAtStalk S = ↑(n + 1)
h✝ : Nontrivial R
this✝³ : Nontrivial S
U : Type u
w✝¹ : CommRing U
w✝ : Algebra S U
e : S ⊗[R] S ≃ₐ[S] S × U
algInst✝ : Algebra (S × U) U := (RingHom.snd S U).toAlgebra
this✝² : IsScalarTower S (S × U) U
this✝¹ : Etale S U
this✝ : Module.Finite S U
this : ∀ (p : PrimeSpectrum S), (Module.rankAtStalk S + Module.rankAtStalk U) p = n + 1
⊢ ∃ T x x_1, ∃ (_ : Module.FaithfullyFlat R T) (_ : Module.Finite R T) (_ : Etale R T), IsFiniteSplit T (T ⊗[R] S)

Tactic:
Module.rankAtStalk_self,

Goal state after:
case succ.inr
n : ℕ
ih :
  ∀ {R S : Type u} [inst : CommRing R] [inst_1 : CommRing S] [inst_2 : Algebra R S] [Etale R S] [Module.Finite R S],
    Module.rankAtStalk S = ↑n →
      ∃ T x x_1, ∃ (_ : Module.FaithfullyFlat R T) (_ : Module.Finite R T) (_ : Etale R T), IsFiniteSplit T (T ⊗[R] S)
R S : Type u
inst✝⁴ : CommRing R
inst✝³ : CommRing S
inst✝² : Algebra R S
inst✝¹ : Etale R S
inst✝ : Module.Finite R S
hn : Module.rankAtStalk S = ↑(n + 1)
h✝ : Nontrivial R
this✝³ : Nontrivial S
U : Type u
w✝¹ : CommRing U
w✝ : Algebra S U
e : S ⊗[R] S ≃ₐ[S] S × U
algInst✝ : Algebra (S × U) U := (RingHom.snd S U).toAlgebra
this✝² : IsScalarTower S (S × U) U
this✝¹ : Etale S U
this✝ : Module.Finite S U
this : ∀ (p : PrimeSpectrum S), (1 + Module.rankAtStalk U) p = n + 1
⊢ ∃ T x x_1, ∃ (_ : Module.FaithfullyFlat R T) (_ : Module.Finite R T) (_ : Etale R T), IsFiniteSplit T (T ⊗[R] S)
Module: Mathlib.RingTheory.DividedPowers.SubDPIdeal

Goal state before:
pp: A : Type u_1
inst✝¹ : CommRing A
I : Ideal A
hI : DividedPowers I
B : Type u_2
inst✝ : CommRing B
J : Ideal B
hJ : DividedPowers J
f : hI.DPMorphism hJ
x✝ : ℕ
hn : x✝ ≠ 0
a : A
ha : f.toRingHom a = 0
ha' : a ∈ I
⊢ hJ.dpow x✝ 0 = 0 ∧ hI.dpow x✝ a ∈ I

Tactic:
exact ⟨dpow_eval_zero hJ hn, hI.dpow_mem hn ha'⟩

Goal state after:
Module: Mathlib.RingTheory.Frobenius

Goal state before:
pp: case inr
R : Type u_1
S : Type u_2
inst✝³ : CommRing R
inst✝² : CommRing S
inst✝¹ : Algebra R S
φ : S →ₐ[R] S
Q : Ideal S
H : φ.IsArithFrobAt Q
inst✝ : IsDomain S
ζ : S
m : ℕ
hζ✝ : ζ ^ m = 1
hk'✝ : ↑m ∉ Q
q : ℕ := Nat.card (R ⧸ Ideal.under R Q)
hm : m ≠ 0
k : ℕ
hk : k > 0
hζ : IsPrimitiveRoot ζ k
hk' : ↑k ∉ Q
this✝ : NeZero k
i : ℕ
hi : i < k
e : ζ ^ i = φ ζ
this : ∀ (j : ℕ), 1 - ζ ^ ((q + k - i) * j) ∈ Q
h₁ : ∑ c ∈ Finset.range k, (1 - ζ ^ ((q + k - i) * c)) ∈ Q
h₂ : ζ ^ q = ζ ^ i
⊢ φ ζ = ζ ^ q

Tactic:
rw [h₂, e]

Goal state after:
Module: Mathlib.RingTheory.Frobenius

Goal state before:
pp: case intro
R : Type u_1
S : Type u_2
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : Algebra R S
G : Type u_3
inst✝⁶ : Group G
inst✝⁵ : MulSemiringAction G S
inst✝⁴ : SMulCommClass G R S
Q : Ideal S
inst✝³ : Finite G
inst✝² : Algebra.IsInvariant R S G
inst✝¹ : Q.IsPrime
inst✝ : Finite (S ⧸ Q)
P : Ideal R := Ideal.under R Q
this✝¹ : Algebra.IsIntegral R S
this✝ : Q.IsMaximal
p : ℕ
hc : CharP (R ⧸ P) p
this : Finite (R ⧸ P)
val✝ : Fintype (R ⧸ P)
⊢ ∃ σ, IsArithFrobAt R σ Q

Tactic:
obtain ⟨k, hp, hk⟩ := FiniteField.card (R ⧸ P) p

Goal state after:
case intro
R : Type u_1
S : Type u_2
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : Algebra R S
G : Type u_3
inst✝⁶ : Group G
inst✝⁵ : MulSemiringAction G S
inst✝⁴ : SMulCommClass G R S
Q : Ideal S
inst✝³ : Finite G
inst✝² : Algebra.IsInvariant R S G
inst✝¹ : Q.IsPrime
inst✝ : Finite (S ⧸ Q)
P : Ideal R := Ideal.under R Q
this✝¹ : Algebra.IsIntegral R S
this✝ : Q.IsMaximal
p : ℕ
hc : CharP (R ⧸ P) p
this : Finite (R ⧸ P)
val✝ : Fintype (R ⧸ P)
k : ℕ+
hp : Nat.Prime p
hk : Fintype.card (R ⧸ P) = p ^ ↑k
⊢ ∃ σ, IsArithFrobAt R σ Q
Module: Mathlib.RingTheory.PowerSeries.WellKnown

Goal state before:
pp: case succ
S : Type u_1
inst✝ : CommRing S
d✝ d : ℕ
hd : mk 1 ^ (d + 1) = mk fun n ↦ ↑((d + n).choose d)
n : ℕ
⊢ ∑ p ∈ Finset.antidiagonal n, (coeff p.1) (mk 1) * (coeff p.2) (mk fun n ↦ ↑((d + n).choose d)) =
    (coeff n) (mk fun n ↦ ↑((d + 1 + n).choose (d + 1)))

Tactic:
simp_rw [coeff_mk, Pi.one_apply, one_mul]

Goal state after:
case succ
S : Type u_1
inst✝ : CommRing S
d✝ d : ℕ
hd : mk 1 ^ (d + 1) = mk fun n ↦ ↑((d + n).choose d)
n : ℕ
⊢ ∑ x ∈ Finset.antidiagonal n, ↑((d + x.2).choose d) = ↑((d + 1 + n).choose (d + 1))
Module: Mathlib.RingTheory.PowerSeries.Binomial

Goal state before:
pp: R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : BinomialRing R
inst✝¹ : Ring A
inst✝ : Algebra R A
d n : ℕ
⊢ (coeff n) (binomialSeries A ↑d) = (coeff n) ((1 + X) ^ d)

Tactic:
have hright : (1 + X) ^ d = (((1 : Polynomial A) + (Polynomial.X)) ^ d).toPowerSeries := by
    simp

Goal state after:
R : Type u_1
A : Type u_2
inst✝³ : CommRing R
inst✝² : BinomialRing R
inst✝¹ : Ring A
inst✝ : Algebra R A
d n : ℕ
hright : (1 + X) ^ d = ↑((1 + Polynomial.X) ^ d)
⊢ (coeff n) (binomialSeries A ↑d) = (coeff n) ((1 + X) ^ d)
Module: Mathlib.RingTheory.HahnSeries.Summable

Goal state before:
pp: case inr
Γ : Type u_1
Γ' : Type u_2
R : Type u_3
V : Type u_4
α : Type u_5
β : Type u_6
inst✝² : PartialOrder Γ
inst✝¹ : AddCommMonoid R
ι : Type ?u.20
inst✝ : Finite ι
x : R⟦Γ⟧
h✝ : Nonempty ι
⊢ (⋃ a, x.support).IsPWO

Tactic:
exact Eq.mpr (congrArg (fun s ↦ s.IsPWO) (Set.iUnion_const x.support)) x.isPWO_support

Goal state after:
Module: Mathlib.RingTheory.HahnSeries.Summable

Goal state before:
pp: Γ : Type u_1
Γ' : Type u_2
R : Type u_3
V : Type u_4
α : Type u_5
β : Type u_6
inst✝² : PartialOrder Γ
inst✝¹ : AddCommMonoid R
ι : Type ?u.20
inst✝ : Finite ι
x : R⟦Γ⟧
⊢ (⋃ a, x.support).IsPWO

Tactic:
cases isEmpty_or_nonempty ι
    · simp
    · exact Eq.mpr (congrArg (fun s ↦ s.IsPWO) (Set.iUnion_const x.support)) x.isPWO_support

Goal state after:
Module: Mathlib.RingTheory.FormalGroup.Basic

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
S : Type u_2
inst✝ : CommRing S
σ✝ : Type u_3
τ : Type u_4
σ : Type u_5
F : FormalGroup R
f : R →+* S
⊢ (coeff (single 1 1)) ((MvPowerSeries.map f) F.toPowerSeries) = 1

Tactic:
simp [F.lin_coeff_Y]

Goal state after:
Module: Mathlib.RingTheory.HahnSeries.Summable

Goal state before:
pp: Γ : Type u_1
Γ' : Type u_2
α : Type u_5
β : Type u_6
inst✝⁶ : PartialOrder Γ
inst✝⁵ : PartialOrder Γ'
inst✝⁴ : VAdd Γ Γ'
inst✝³ : IsOrderedCancelVAdd Γ Γ'
R : Type u_7
V : Type u_8
inst✝² : Semiring R
inst✝¹ : AddCommMonoid V
inst✝ : Module R V
s : SummableFamily Γ R α
t : SummableFamily Γ' V β
g : Γ'
⊢ (s.smul t).hsum.coeff g = ∑ gh ∈ VAddAntidiagonal g ⋯, s.hsum.coeff gh.1 • t.hsum.coeff gh.2

Tactic:
rw [coeff_hsum]

Goal state after:
Γ : Type u_1
Γ' : Type u_2
α : Type u_5
β : Type u_6
inst✝⁶ : PartialOrder Γ
inst✝⁵ : PartialOrder Γ'
inst✝⁴ : VAdd Γ Γ'
inst✝³ : IsOrderedCancelVAdd Γ Γ'
R : Type u_7
V : Type u_8
inst✝² : Semiring R
inst✝¹ : AddCommMonoid V
inst✝ : Module R V
s : SummableFamily Γ R α
t : SummableFamily Γ' V β
g : Γ'
⊢ ∑ᶠ (i : α × β), ((s.smul t) i).coeff g = ∑ gh ∈ VAddAntidiagonal g ⋯, s.hsum.coeff gh.1 • t.hsum.coeff gh.2
Module: Mathlib.RingTheory.FormalGroup.Basic

Goal state before:
pp: R : Type u_1
inst✝ : CommRing R
F : FormalGroup R
⊢ (coeff (single 1 1)) F.toPowerSeries • (coeff (single () 1)) ((single 1 1).prod fun s e ↦ ![0, PowerSeries.X] s ^ e) =
    1

Tactic:
simp [F.lin_coeff_Y]

Goal state after:
Module: Mathlib.RingTheory.HahnSeries.Summable

Goal state before:
pp: case refine_1.left
Γ : Type u_1
Γ' : Type u_2
α : Type u_5
β : Type u_6
inst✝⁶ : PartialOrder Γ
inst✝⁵ : PartialOrder Γ'
inst✝⁴ : VAdd Γ Γ'
inst✝³ : IsOrderedCancelVAdd Γ Γ'
R : Type u_7
V : Type u_8
inst✝² : Semiring R
inst✝¹ : AddCommMonoid V
inst✝ : Module R V
s : SummableFamily Γ R α
t : SummableFamily Γ' V β
g : Γ'
x✝ : Γ × Γ'
hgh : ¬∑ i ∈ (s.coeff x✝.1).support, (s i).coeff x✝.1 = 0 ∧ ¬t.hsum.coeff x✝.2 = 0 ∧ x✝.1 +ᵥ x✝.2 = g
h' : ∃ a ∈ (s.coeff x✝.1).support, (s a).coeff x✝.1 ≠ 0
⊢ ∃ i, ¬(s i).coeff x✝.1 = 0

Tactic:
simpa using h'

Goal state after:
Module: Mathlib.RingTheory.HahnSeries.Summable

Goal state before:
pp: Γ : Type u_1
Γ' : Type u_2
R : Type u_3
V : Type u_4
α : Type u_5
β : Type u_6
inst✝¹ : PartialOrder Γ
inst✝ : AddCommMonoid R
f : α →₀ R⟦Γ⟧
a : α
g : Γ
hg : g ∈ (f a).support
⊢ g ∈ ⋃ i ∈ f.support, (f i).support

Tactic:
have haf : a ∈ f.support := by
      rw [Finsupp.mem_support_iff, ← support_nonempty_iff]
      exact ⟨g, hg⟩

Goal state after:
Γ : Type u_1
Γ' : Type u_2
R : Type u_3
V : Type u_4
α : Type u_5
β : Type u_6
inst✝¹ : PartialOrder Γ
inst✝ : AddCommMonoid R
f : α →₀ R⟦Γ⟧
a : α
g : Γ
hg : g ∈ (f a).support
haf : a ∈ f.support
⊢ g ∈ ⋃ i ∈ f.support, (f i).support
Module: Mathlib.RingTheory.HahnSeries.Cardinal

Goal state before:
pp: case inr
Γ : Type u_1
R : Type u_2
inst✝³ : LinearOrder Γ
inst✝² : AddCommGroup Γ
inst✝¹ : IsOrderedAddMonoid Γ
inst✝ : Field R
x : R⟦Γ⟧
hx : x ≠ 0
⊢ x⁻¹.cardSupp ≤ max ℵ₀ x.cardSupp

Tactic:
apply (cardSupp_single_mul_le ..).trans (cardSupp_hsum_powers_le ..) |>.trans

Goal state after:
case inr
Γ : Type u_1
R : Type u_2
inst✝³ : LinearOrder Γ
inst✝² : AddCommGroup Γ
inst✝¹ : IsOrderedAddMonoid Γ
inst✝ : Field R
x : R⟦Γ⟧
hx : x ≠ 0
⊢ max ℵ₀ (1 - (single (-x.order)) x.leadingCoeff⁻¹ * x).cardSupp ≤ max ℵ₀ x.cardSupp
Module: Mathlib.RingTheory.HahnSeries.Summable

Goal state before:
pp: Γ : Type u_1
R : Type u_3
inst✝³ : AddCommMonoid Γ
inst✝² : LinearOrder Γ
inst✝¹ : IsOrderedCancelAddMonoid Γ
inst✝ : CommRing R
x y : R⟦Γ⟧
r : R
hr : r * x.leadingCoeff = 1
hxy : x = y + (single x.order) x.leadingCoeff
oinv : Γ
hxo : oinv + x.order = 0
⊢ 1 - ((single oinv) r * y + (single 0) 1) = -((single oinv) r * y)

Tactic:
sub_add_eq_sub_sub_swap,

Goal state after:
Γ : Type u_1
R : Type u_3
inst✝³ : AddCommMonoid Γ
inst✝² : LinearOrder Γ
inst✝¹ : IsOrderedCancelAddMonoid Γ
inst✝ : CommRing R
x y : R⟦Γ⟧
r : R
hr : r * x.leadingCoeff = 1
hxy : x = y + (single x.order) x.leadingCoeff
oinv : Γ
hxo : oinv + x.order = 0
⊢ 1 - (single 0) 1 - (single oinv) r * y = -((single oinv) r * y)
Module: Mathlib.RingTheory.Henselian

Goal state before:
pp: case succ
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
n : ℕ
ih : c n ≡ a₀ [SMOD I]
⊢ c (n + 1) ≡ a₀ [SMOD I]

Tactic:
hc,

Goal state after:
case succ
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
n : ℕ
ih : c n ≡ a₀ [SMOD I]
⊢ c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ ≡ a₀ [SMOD I]
Module: Mathlib.RingTheory.Henselian

Goal state before:
pp: case succ
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
hc_mod : ∀ (n : ℕ), c n ≡ a₀ [SMOD I]
hf'c : ∀ (n : ℕ), IsUnit (Polynomial.eval (c n) f')
n : ℕ
ih : Polynomial.eval (c n) f ∈ I ^ (n + 1)
⊢ Polynomial.eval (c (n + 1) - c n) ((taylor (c n)) f) ∈ I ^ (n + 1 + 1)

Tactic:
hc,

Goal state after:
case succ
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
hc_mod : ∀ (n : ℕ), c n ≡ a₀ [SMOD I]
hf'c : ∀ (n : ℕ), IsUnit (Polynomial.eval (c n) f')
n : ℕ
ih : Polynomial.eval (c n) f ∈ I ^ (n + 1)
⊢ Polynomial.eval (c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ - c n) ((taylor (c n)) f) ∈
    I ^ (n + 1 + 1)
Module: Mathlib.RingTheory.Henselian

Goal state before:
pp: case succ
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
hc_mod : ∀ (n : ℕ), c n ≡ a₀ [SMOD I]
hf'c : ∀ (n : ℕ), IsUnit (Polynomial.eval (c n) f')
hfcI : ∀ (n : ℕ), Polynomial.eval (c n) f ∈ I ^ (n + 1)
m k : ℕ
ih : c m ≡ c (m + k) [SMOD I ^ m]
⊢ c m ≡ c (m + k + 1) [SMOD I ^ m]

Tactic:
hc,

Goal state after:
case succ
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
hc_mod : ∀ (n : ℕ), c n ≡ a₀ [SMOD I]
hf'c : ∀ (n : ℕ), IsUnit (Polynomial.eval (c n) f')
hfcI : ∀ (n : ℕ), Polynomial.eval (c n) f ∈ I ^ (n + 1)
m k : ℕ
ih : c m ≡ c (m + k) [SMOD I ^ m]
⊢ c m ≡ c (m + k) - Polynomial.eval (c (m + k)) f * (Polynomial.eval (c (m + k)) f')⁻¹ʳ [SMOD I ^ m]
Module: Mathlib.RingTheory.Henselian

Goal state before:
pp: case refine_2
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
hc_mod : ∀ (n : ℕ), c n ≡ a₀ [SMOD I]
hf'c : ∀ (n : ℕ), IsUnit (Polynomial.eval (c n) f')
hfcI : ∀ (n : ℕ), Polynomial.eval (c n) f ∈ I ^ (n + 1)
aux : ∀ (m n : ℕ), m ≤ n → c m ≡ c n [SMOD I ^ m • ⊤]
a : R
ha : c (0 + 1) ≡ a [SMOD I ^ (0 + 1) • ⊤]
⊢ a - a₀ ∈ I

Tactic:
hc,

Goal state after:
case refine_2
R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
inst✝ : IsAdicComplete I R
f : R[X]
x✝ : f.Monic
a₀ : R
h₁ : Polynomial.eval a₀ f ∈ I
h₂ : IsUnit ((Ideal.Quotient.mk I) (Polynomial.eval a₀ (derivative f)))
f' : R[X] := derivative f
c : ℕ → R := fun n ↦ Nat.recOn n a₀ fun x b ↦ b - Polynomial.eval b f * (Polynomial.eval b f')⁻¹ʳ
hc : ∀ (n : ℕ), c (n + 1) = c n - Polynomial.eval (c n) f * (Polynomial.eval (c n) f')⁻¹ʳ
hc_mod : ∀ (n : ℕ), c n ≡ a₀ [SMOD I]
hf'c : ∀ (n : ℕ), IsUnit (Polynomial.eval (c n) f')
hfcI : ∀ (n : ℕ), Polynomial.eval (c n) f ∈ I ^ (n + 1)
aux : ∀ (m n : ℕ), m ≤ n → c m ≡ c n [SMOD I ^ m • ⊤]
a : R
ha : c 0 - Polynomial.eval (c 0) f * (Polynomial.eval (c 0) f')⁻¹ʳ ≡ a [SMOD I ^ (0 + 1) • ⊤]
⊢ a - a₀ ∈ I
Module: Mathlib.RingTheory.Ideal.Pure

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
I J : Ideal R
inst✝ : I.Pure
⊢ I ⊓ J = I * J

Tactic:
← injective_lTensor_quotient_iff_inf_eq_mul

Goal state after:
R : Type u_1
inst✝¹ : CommRing R
I J : Ideal R
inst✝ : I.Pure
⊢ Function.Injective ⇑(LinearMap.lTensor (R ⧸ I) (Submodule.subtype J))
Module: Mathlib.RingTheory.Ideal.Pure

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
I : Ideal R
h : ∀ x ∈ I, ∃ y ∈ I, x = x * y
p : Ideal R
inst✝ : p.IsPrime
hle : I ≤ p
⊢ I ≤ RingHom.ker (algebraMap R (Localization.AtPrime p))

Tactic:
intro x hx
  obtain ⟨y, hy, heq⟩ := h _ hx
  have : IsUnit (algebraMap R (Localization.AtPrime p) (1 - y)) := by
    rw [IsLocalization.algebraMap_isUnit_iff p.primeCompl]
    refine ⟨1 - y, fun hz ↦ p.one_notMem ?_, by simp⟩
    rw [← sub_add_cancel 1 y]
    exact Ideal.add_mem _ hz (hle hy)
  have hzero : x * (1 - y) = 0 := by simp [mul_sub, ← heq]
  simp only [RingHom.mem_ker, ← this.mul_left_eq_zero, ← RingHom.map_mul, hzero, RingHom.map_zero]

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

Goal state before:
pp: case refine_2
R : Type u_1
inst✝² : CommRing R
inst✝¹ : IsLocalRing R
inst✝ : IsDomain R
h : ringKrullDim R = 1
⊢ ∀ (x : R), x ≠ 0 → IsLocalRing.maximalIdeal R ≤ (Ideal.span {x}).radical

Tactic:
intro x hx
    rw [Ideal.radical_eq_sInf]
    refine le_sInf (fun J ⟨hJ1, hJ2⟩ ↦ ?_)
    have : J.IsMaximal :=
      Ring.krullDimLE_one_iff_of_noZeroDivisors.mp (Ring.krullDimLE_iff.mpr (by simp [h]))
        J (fun hJ3 ↦ hx (by simp_all)) hJ2
    exact le_of_eq (IsLocalRing.eq_maximalIdeal this).symm

Goal state after:
Module: Mathlib.Topology.Algebra.Category.ProfiniteGrp.Limits

Goal state before:
pp: case h
P : ProfiniteGrp.{u}
U : Set ↑(limit P.diagram).toProfinite.toTop
s : Set ((j : OpenNormalSubgroup ↑P.toProfinite.toTop) → ↑(P.diagram.obj j).toProfinite.toTop)
hsO : IsOpen s
hsv : Subtype.val ⁻¹' s = U
spc : (j : OpenNormalSubgroup ↑P.toProfinite.toTop) → ↑(P.diagram.obj j).toProfinite.toTop
hspc : spc ∈ limitConePtAux P.diagram
uDefaultSpec : spc ∈ s
J : Finset (OpenNormalSubgroup ↑P.toProfinite.toTop)
fJ : (a : OpenNormalSubgroup ↑P.toProfinite.toTop) → Set ↑(P.diagram.obj a).toProfinite.toTop
hJ1 : ∀ a ∈ J, IsOpen (fJ a) ∧ spc a ∈ fJ a
hJ2 : (↑J).pi fJ ⊆ s
M : Subgroup ↑P.toProfinite.toTop := ⨅ j, ↑(↑j).toOpenSubgroup
hM : M.Normal
hMOpen : IsOpen ↑M
m : OpenNormalSubgroup ↑P.toProfinite.toTop := { toSubgroup := M, isOpen' := hMOpen, isNormal' := ⋯ }
origin : ↑P.toProfinite.toTop
horigin : (QuotientGroup.mk' M) origin = spc m
a : OpenNormalSubgroup ↑P.toProfinite.toTop
⊢ a ∈ ↑J → ↑((Hom.hom P.toLimit) origin) a ∈ fJ a

Tactic:
a_in_J

Goal state after:
case h
P : ProfiniteGrp.{u}
U : Set ↑(limit P.diagram).toProfinite.toTop
s : Set ((j : OpenNormalSubgroup ↑P.toProfinite.toTop) → ↑(P.diagram.obj j).toProfinite.toTop)
hsO : IsOpen s
hsv : Subtype.val ⁻¹' s = U
spc : (j : OpenNormalSubgroup ↑P.toProfinite.toTop) → ↑(P.diagram.obj j).toProfinite.toTop
hspc : spc ∈ limitConePtAux P.diagram
uDefaultSpec : spc ∈ s
J : Finset (OpenNormalSubgroup ↑P.toProfinite.toTop)
fJ : (a : OpenNormalSubgroup ↑P.toProfinite.toTop) → Set ↑(P.diagram.obj a).toProfinite.toTop
hJ1 : ∀ a ∈ J, IsOpen (fJ a) ∧ spc a ∈ fJ a
hJ2 : (↑J).pi fJ ⊆ s
M : Subgroup ↑P.toProfinite.toTop := ⨅ j, ↑(↑j).toOpenSubgroup
hM : M.Normal
hMOpen : IsOpen ↑M
m : OpenNormalSubgroup ↑P.toProfinite.toTop := { toSubgroup := M, isOpen' := hMOpen, isNormal' := ⋯ }
origin : ↑P.toProfinite.toTop
horigin : (QuotientGroup.mk' M) origin = spc m
a : OpenNormalSubgroup ↑P.toProfinite.toTop
a_in_J : a ∈ ↑J
⊢ ↑((Hom.hom P.toLimit) origin) a ∈ fJ a