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
⊢ length B ↥(Submodule.baseChange B q) =
    length B ↥(Submodule.baseChange B p) + length B (B ⧸ Ideal.map (algebraMap A B) (maximalIdeal A))

Tactic:
rw [← (toBaseChange.toLinearEquiv B p).length_eq, ← (toBaseChange.toLinearEquiv B q).length_eq]
  -- Identify q / p with A / m_A, so (B ⊗[A] p ⧸ B ⊗[A] q) ≃ₗ B ⧸ m_A B
  let f : p →ₗ[A] q := inclusion h.le
  have key : IsSimpleModule A (q ⧸ f.range) := by
    rwa [range_inclusion, ← covBy_iff_quot_is_simple h.le]
  obtain ⟨m, hm, ⟨e⟩⟩ := isSimpleModule_iff_quot_maximal.mp key
  obtain rfl := eq_maximalIdeal hm
  -- `0 -> B ⊗[A] p -> B ⊗[A] q -> B ⧸ m_A B -> 0` is exact by flatness, and length is additive
  let g := e.comp f.range.mkQ
  have : Function.Injective f := inclusion_injective _
  have : Function.Surjective g := e.surjective.comp f.range.mkQ_surjective
  have : Function.Exact f g := exact_iff.mpr (by simp [f, g])
  have : FaithfullyFlat A B := FaithfullyFlat.of_flat_of_isLocalHom
  rw [length_eq_add_of_exact (lTensor B B f) (lTensor B B g) (by simpa) (by simpa) (by simpa),
    (Algebra.TensorProduct.quotIdealMapEquivTensorQuot B (maximalIdeal A)).toLinearEquiv.length_eq]

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

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : QuasiFinite R S
f : S →ₐ[R] T
H : ∀ (x : T), ∃ s, IsUnit (f s) ∧ x * f s ∈ f.range
φ : Localization (Submonoid.comap f (IsUnit.submonoid T)) →ₐ[R] T := IsLocalization.liftAlgHom ⋯
⊢ QuasiFinite R T

Tactic:
suffices Function.Surjective φ from .of_surjective_algHom φ this

Goal state after:
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : QuasiFinite R S
f : S →ₐ[R] T
H : ∀ (x : T), ∃ s, IsUnit (f s) ∧ x * f s ∈ f.range
φ : Localization (Submonoid.comap f (IsUnit.submonoid T)) →ₐ[R] T := IsLocalization.liftAlgHom ⋯
⊢ Function.Surjective ⇑φ
Module: Mathlib.RingTheory.QuasiFinite.Basic

Goal state before:
pp: R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : CommRing T
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R T
inst✝⁴ : Algebra S T
inst✝³ : IsScalarTower R S T
inst✝² : Algebra.IsIntegral R S
inst✝¹ : FiniteType R T
s : S
inst✝ : IsLocalization.Away s T
A : Subalgebra R S := R[s]
sA : ↥A := ⟨s, ⋯⟩
f : Localization.Away sA →+* T := IsLocalization.Away.lift sA ⋯
this✝³ : Algebra (Localization.Away sA) T := f.toAlgebra
this✝² : Algebra (↥A) (Localization.Away sA) := OreLocalization.instAlgebra
this✝¹ : SMul (↥A) (Localization.Away sA) := this✝².toSMul
this✝ : MulAction (↥A) (Localization.Away sA) := toModule.toMulAction
this : IsScalarTower R (↥A) (Localization.Away sA)
⊢ QuasiFinite R T

Tactic:
have : IsScalarTower A (Localization.Away sA) T :=
    .of_algebraMap_eq (by simp [f, RingHom.algebraMap_toAlgebra, A])

Goal state after:
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁹ : CommRing R
inst✝⁸ : CommRing S
inst✝⁷ : CommRing T
inst✝⁶ : Algebra R S
inst✝⁵ : Algebra R T
inst✝⁴ : Algebra S T
inst✝³ : IsScalarTower R S T
inst✝² : Algebra.IsIntegral R S
inst✝¹ : FiniteType R T
s : S
inst✝ : IsLocalization.Away s T
A : Subalgebra R S := R[s]
sA : ↥A := ⟨s, ⋯⟩
f : Localization.Away sA →+* T := IsLocalization.Away.lift sA ⋯
this✝⁴ : Algebra (Localization.Away sA) T := f.toAlgebra
this✝³ : Algebra (↥A) (Localization.Away sA) := OreLocalization.instAlgebra
this✝² : SMul (↥A) (Localization.Away sA) := this✝³.toSMul
this✝¹ : MulAction (↥A) (Localization.Away sA) := toModule.toMulAction
this✝ : IsScalarTower R (↥A) (Localization.Away sA)
this : IsScalarTower (↥A) (Localization.Away sA) T
⊢ QuasiFinite R T
Module: Mathlib.RingTheory.Unramified.Finite

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
inst✝² : FormallyUnramified R S
inst✝¹ : EssFiniteType R S
inst✝ : Free R S
I : Type u_2 := ⋯
b : Basis I R S := ⋯
f : I →₀ S
hf : elem R S = f.sum fun i x ↦ x ⊗ₜ[R] b i
x : S
a : I → I →₀ R := ⋯
F : I →₀ I →₀ R := ⋯
hG : ∀ j ∉ f.support.biUnion fun i ↦ (a i).support, b.repr (f.sum fun i y ↦ (a i) j • y) = 0
G : I →₀ I →₀ R := ⋯
⊢ Finsupp.curryEquiv.symm F = Finsupp.curryEquiv.symm G

Tactic:
apply (Finsupp.equivCongrLeft (Equiv.prodComm I I)).injective

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
inst✝² : FormallyUnramified R S
inst✝¹ : EssFiniteType R S
inst✝ : Free R S
I : Type u_2 := ⋯
b : Basis I R S := ⋯
f : I →₀ S
hf : elem R S = f.sum fun i x ↦ x ⊗ₜ[R] b i
x : S
a : I → I →₀ R := ⋯
F : I →₀ I →₀ R := ⋯
hG : ∀ j ∉ f.support.biUnion fun i ↦ (a i).support, b.repr (f.sum fun i y ↦ (a i) j • y) = 0
G : I →₀ I →₀ R := ⋯
⊢ (Finsupp.equivCongrLeft (Equiv.prodComm I I)) (Finsupp.curryEquiv.symm F) =
    (Finsupp.equivCongrLeft (Equiv.prodComm I I)) (Finsupp.curryEquiv.symm G)
Module: Mathlib.RingTheory.Unramified.Finite

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
inst✝² : FormallyUnramified R S
inst✝¹ : EssFiniteType R S
inst✝ : Free R S
I : Type u_2 := Free.ChooseBasisIndex R S
b : Basis I R S := Free.chooseBasis R S
f : I →₀ S
hf : elem R S = f.sum fun i x ↦ x ⊗ₜ[R] b i
x : S
a : I → I →₀ R := fun i ↦ b.repr (b i * x)
F : I →₀ I →₀ R := Finsupp.onFinset f.support (fun j ↦ b.repr (x * f j)) ⋯
hG : ∀ j ∉ f.support.biUnion fun i ↦ (a i).support, b.repr (f.sum fun i y ↦ (a i) j • y) = 0
G : I →₀ I →₀ R :=
  Finsupp.onFinset (f.support.biUnion fun i ↦ (a i).support) (fun j ↦ b.repr (f.sum fun i y ↦ (a i) j • y)) ⋯
this : ∀ (i : I), ((b.repr (x * f i)).sum fun j k ↦ k • b j ⊗ₜ[R] b i) = (x * f i) ⊗ₜ[R] b i
⊢ (F.sum fun a f ↦ f.sum fun b' c ↦ c • b b' ⊗ₜ[R] b a) = G.sum fun a f ↦ f.sum fun b' c ↦ c • b b' ⊗ₜ[R] b a

Tactic:
Finsupp.onFinset_sum,

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
inst✝² : FormallyUnramified R S
inst✝¹ : EssFiniteType R S
inst✝ : Free R S
I : Type u_2 := Free.ChooseBasisIndex R S
b : Basis I R S := Free.chooseBasis R S
f : I →₀ S
hf : elem R S = f.sum fun i x ↦ x ⊗ₜ[R] b i
x : S
a : I → I →₀ R := fun i ↦ b.repr (b i * x)
F : I →₀ I →₀ R := Finsupp.onFinset f.support (fun j ↦ b.repr (x * f j)) ⋯
hG : ∀ j ∉ f.support.biUnion fun i ↦ (a i).support, b.repr (f.sum fun i y ↦ (a i) j • y) = 0
G : I →₀ I →₀ R :=
  Finsupp.onFinset (f.support.biUnion fun i ↦ (a i).support) (fun j ↦ b.repr (f.sum fun i y ↦ (a i) j • y)) ⋯
this : ∀ (i : I), ((b.repr (x * f i)).sum fun j k ↦ k • b j ⊗ₜ[R] b i) = (x * f i) ⊗ₜ[R] b i
⊢ (∑ a ∈ f.support, (b.repr (x * f a)).sum fun b' c ↦ c • b b' ⊗ₜ[R] b a) =
    G.sum fun a f ↦ f.sum fun b' c ↦ c • b b' ⊗ₜ[R] b a

case hg
R : Type u_1
S : Type u_2
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : Algebra R S
inst✝² : FormallyUnramified R S
inst✝¹ : EssFiniteType R S
inst✝ : Free R S
I : Type u_2 := Free.ChooseBasisIndex R S
b : Basis I R S := Free.chooseBasis R S
f : I →₀ S
hf : elem R S = f.sum fun i x ↦ x ⊗ₜ[R] b i
x : S
a : I → I →₀ R := fun i ↦ b.repr (b i * x)
F : I →₀ I →₀ R := Finsupp.onFinset f.support (fun j ↦ b.repr (x * f j)) ⋯
hG : ∀ j ∉ f.support.biUnion fun i ↦ (a i).support, b.repr (f.sum fun i y ↦ (a i) j • y) = 0
G : I →₀ I →₀ R :=
  Finsupp.onFinset (f.support.biUnion fun i ↦ (a i).support) (fun j ↦ b.repr (f.sum fun i y ↦ (a i) j • y)) ⋯
this : ∀ (i : I), ((b.repr (x * f i)).sum fun j k ↦ k • b j ⊗ₜ[R] b i) = (x * f i) ⊗ₜ[R] b i
⊢ ∀ (a : I), (Finsupp.sum 0 fun b' c ↦ c • b b' ⊗ₜ[R] b a) = 0
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: case h2
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
x : (Q.comp P).Ring
hx' : x ∈ (Q.comp P).toExtension.ker
y : (Q.comp P).Ring
hy : y ∈ (Q.comp P).ker * (Q.comp P).ker
e : x - y ∈ Ideal.map (Q.toComp P).toAlgHom P.ker
z : ↥(Q.comp P).ker := ⟨x - y, ⋯⟩
⊢ Extension.Cotangent.mk ⟨x, hx'⟩ ∈ Submodule.span T ↑(Extension.Cotangent.map (Q.toComp P).toExtensionHom).range

Tactic:
have hz : z.1 ∈ P.ker.map (Q.toComp P).toAlgHom.toRingHom := e

Goal state after:
case h2
R : Type u₁
S : Type u₂
inst✝⁶ : CommRing R
inst✝⁵ : CommRing S
inst✝⁴ : Algebra R S
T : Type u₃
inst✝³ : CommRing T
inst✝² : Algebra R T
inst✝¹ : Algebra S T
inst✝ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
x : (Q.comp P).Ring
hx' : x ∈ (Q.comp P).toExtension.ker
y : (Q.comp P).Ring
hy : y ∈ (Q.comp P).ker * (Q.comp P).ker
e : x - y ∈ Ideal.map (Q.toComp P).toAlgHom P.ker
z : ↥(Q.comp P).ker := ⟨x - y, ⋯⟩
hz : ↑z ∈ Ideal.map (Q.toComp P).toAlgHom.toRingHom P.ker
⊢ Extension.Cotangent.mk ⟨x, hx'⟩ ∈ Submodule.span T ↑(Extension.Cotangent.map (Q.toComp P).toExtensionHom).range
Module: Mathlib.RingTheory.Unramified.Locus

Goal state before:
pp: R : Type u_1
A : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
f : A
⊢ Subsingleton (LocalizedModule.Away f Ω[A⁄R]) ↔ FormallyUnramified R (Localization.Away f)

Tactic:
Algebra.formallyUnramified_iff

Goal state after:
R : Type u_1
A : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
f : A
⊢ Subsingleton (LocalizedModule.Away f Ω[A⁄R]) ↔ Subsingleton Ω[Localization.Away f⁄R]
Module: Mathlib.RingTheory.Unramified.Locus

Goal state before:
pp: R : Type u_1
A : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
⊢ Subsingleton Ω[A⁄R] ↔ FormallyUnramified R A

Tactic:
Algebra.formallyUnramified_iff

Goal state after:
R : Type u_1
A : Type u_2
inst✝² : CommRing R
inst✝¹ : CommRing A
inst✝ : Algebra R A
⊢ Subsingleton Ω[A⁄R] ↔ Subsingleton Ω[A⁄R]
Module: Mathlib.RingTheory.Unramified.LocalRing

Goal state before:
pp: R : Type u_1
S : Type u_2
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
inst✝⁴ : IsLocalRing R
inst✝³ : IsLocalRing S
inst✝² : IsLocalHom (algebraMap R S)
inst✝¹ : EssFiniteType R S
inst✝ : Algebra.IsSeparable (ResidueField R) (ResidueField S)
H : Ideal.map (algebraMap R S) (maximalIdeal R) = maximalIdeal S
this : FormallyUnramified (ResidueField R) (ResidueField S)
⊢ Subsingleton Ω[S⁄R]

Tactic:
have : FormallyUnramified R (ResidueField S) := .comp _ (ResidueField R) _

Goal state after:
R : Type u_1
S : Type u_2
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
inst✝⁴ : IsLocalRing R
inst✝³ : IsLocalRing S
inst✝² : IsLocalHom (algebraMap R S)
inst✝¹ : EssFiniteType R S
inst✝ : Algebra.IsSeparable (ResidueField R) (ResidueField S)
H : Ideal.map (algebraMap R S) (maximalIdeal R) = maximalIdeal S
this✝ : FormallyUnramified (ResidueField R) (ResidueField S)
this : FormallyUnramified R (ResidueField S)
⊢ Subsingleton Ω[S⁄R]
Module: Mathlib.RingTheory.Kaehler.JacobiZariski

Goal state before:
pp: R : Type u₁
S : Type u₂
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
T : Type u₃
inst✝⁴ : CommRing T
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
inst✝ : Flat S T
x : T ⊗[S] P.toExtension.Cotangent
x_in✝ :
  (liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)) x ∈
    (Q.comp P).toExtension.cotangentComplex.ker
x_in :
  (Q.comp P).toExtension.cotangentComplex ((liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)) x) =
    0
⊢ ⟨(liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)) x, x_in✝⟩ ∈
    (liftBaseChange T (Extension.H1Cotangent.map (Q.toComp P).toExtensionHom)).range

Tactic:
← comp_apply,

Goal state after:
R : Type u₁
S : Type u₂
inst✝⁷ : CommRing R
inst✝⁶ : CommRing S
inst✝⁵ : Algebra R S
T : Type u₃
inst✝⁴ : CommRing T
inst✝³ : Algebra R T
inst✝² : Algebra S T
inst✝¹ : IsScalarTower R S T
ι : Type w₁
σ : Type w₂
Q : Generators S T ι
P : Generators R S σ
inst✝ : Flat S T
x : T ⊗[S] P.toExtension.Cotangent
x_in✝ :
  (liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)) x ∈
    (Q.comp P).toExtension.cotangentComplex.ker
x_in :
  ((Q.comp P).toExtension.cotangentComplex ∘ₗ liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom))
      x =
    0
⊢ ⟨(liftBaseChange T (Extension.Cotangent.map (Q.toComp P).toExtensionHom)) x, x_in✝⟩ ∈
    (liftBaseChange T (Extension.H1Cotangent.map (Q.toComp P).toExtensionHom)).range
Module: Mathlib.Combinatorics.Enumerative.InclusionExclusion

Goal state before:
pp: case a.a
ι : Type u_1
α : Type u_2
G : Type u_3
inst✝¹ : AddCommGroup G
inst✝ : DecidableEq α
s : Finset ι
S : ι → Finset α
f : α → G
t : α
a✝¹ : t ∈ s.biUnion S
x✝ : ι
a✝ : x✝ ∈ s
⊢ 1 = (↑(s.biUnion S)).indicator 1 t

Tactic:
Set.indicator_of_mem ‹_›,

Goal state after:
case a.a
ι : Type u_1
α : Type u_2
G : Type u_3
inst✝¹ : AddCommGroup G
inst✝ : DecidableEq α
s : Finset ι
S : ι → Finset α
f : α → G
t : α
a✝¹ : t ∈ s.biUnion S
x✝ : ι
a✝ : x✝ ∈ s
⊢ 1 = 1 t
Module: Mathlib.Data.ENNReal.Basic

Goal state before:
pp: x y : ℝ≥0∞
hx : x ≠ ∞
hy : y ≠ ∞
⊢ x.toReal = y.toReal ↔ x = y

Tactic:
by
  simp only [ENNReal.toReal, NNReal.coe_inj, toNNReal_eq_toNNReal_iff' hx hy]

Goal state after:
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: case neg
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝⁴ : AddGroup E
inst✝³ : SMul R ℝ
inst✝² : SMul R ℝ≥0
inst✝¹ : IsScalarTower R ℝ≥0 ℝ
inst✝ : DecidableEq E
x y : E
hx : ¬x = 0
⊢ (if x + y = 0 then 0 else 1) ≤ (if x = 0 then 0 else 1) + if y = 0 then 0 else 1

Tactic:
if_neg hx

Goal state after:
case neg
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝⁴ : AddGroup E
inst✝³ : SMul R ℝ
inst✝² : SMul R ℝ≥0
inst✝¹ : IsScalarTower R ℝ≥0 ℝ
inst✝ : DecidableEq E
x y : E
hx : ¬x = 0
⊢ (if x + y = 0 then 0 else 1) ≤ 1 + if y = 0 then 0 else 1
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: case neg
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝⁴ : Group E
inst✝³ : SMul R ℝ
inst✝² : SMul R ℝ≥0
inst✝¹ : IsScalarTower R ℝ≥0 ℝ
inst✝ : DecidableEq E
x y : E
hx : ¬x = 1
⊢ (if x * y = 1 then 0 else 1) ≤ (if x = 1 then 0 else 1) + if y = 1 then 0 else 1

Tactic:
if_neg hx

Goal state after:
case neg
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝⁴ : Group E
inst✝³ : SMul R ℝ
inst✝² : SMul R ℝ≥0
inst✝¹ : IsScalarTower R ℝ≥0 ℝ
inst✝ : DecidableEq E
x y : E
hx : ¬x = 1
⊢ (if x * y = 1 then 0 else 1) ≤ 1 + if y = 1 then 0 else 1
Module: Mathlib.Analysis.Normed.Group.Seminorm

Goal state before:
pp: case neg
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝⁴ : AddGroup E
inst✝³ : SMul R ℝ
inst✝² : SMul R ℝ≥0
inst✝¹ : IsScalarTower R ℝ≥0 ℝ
inst✝ : DecidableEq E
x y : E
hx : ¬x = 0
⊢ (if x + y = 0 then 0 else 1) ≤ max (if x = 0 then 0 else 1) (if y = 0 then 0 else 1)

Tactic:
if_neg hx

Goal state after:
case neg
R : Type u_1
R' : Type u_2
E : Type u_3
F : Type u_4
G : Type u_5
inst✝⁴ : AddGroup E
inst✝³ : SMul R ℝ
inst✝² : SMul R ℝ≥0
inst✝¹ : IsScalarTower R ℝ≥0 ℝ
inst✝ : DecidableEq E
x y : E
hx : ¬x = 0
⊢ (if x + y = 0 then 0 else 1) ≤ max 1 (if y = 0 then 0 else 1)
Module: Mathlib.Topology.Order.T5

Goal state before:
pp: X : Type u_1
inst✝² : LinearOrder X
inst✝¹ : TopologicalSpace X
inst✝ : OrderTopology X
a : X
s : Set X
⊢ s.ordConnectedComponent a ∈ 𝓝 a ↔ s ∈ 𝓝 a

Tactic:
refine ⟨fun h => mem_of_superset h ordConnectedComponent_subset, fun h => ?_⟩

Goal state after:
X : Type u_1
inst✝² : LinearOrder X
inst✝¹ : TopologicalSpace X
inst✝ : OrderTopology X
a : X
s : Set X
h : s ∈ 𝓝 a
⊢ s.ordConnectedComponent a ∈ 𝓝 a
Module: Mathlib.Data.ENNReal.Operations

Goal state before:
pp: a : ℝ≥0∞
s : Set ℝ≥0∞
⊢ sInf s + a = ⨅ b ∈ s, b + a

Tactic:
by simp [sInf_eq_iInf, iInf_add]

Goal state after:
Module: Mathlib.Data.ENNReal.Operations

Goal state before:
pp: case inr
ι : Sort u_1
f g : ι → ℝ≥0∞
h : ∀ (i j : ι), ∃ k, f i + g j ≤ f k + g k
h✝ : Nonempty ι
i j : ι
⊢ f i + g j ≤ ⨆ i, f i + g i

Tactic:
rcases h i j with ⟨k, hk⟩

Goal state after:
case inr
ι : Sort u_1
f g : ι → ℝ≥0∞
h : ∀ (i j : ι), ∃ k, f i + g j ≤ f k + g k
h✝ : Nonempty ι
i j k : ι
hk : f i + g j ≤ f k + g k
⊢ f i + g j ≤ ⨆ i, f i + g i
Module: Mathlib.Data.ENNReal.Inv

Goal state before:
pp: c a b : ℝ≥0∞
hc : c ≠ 0
hc' : c ≠ ∞
⊢ c * a / (c * b) = a / b

Tactic:
by
  rw [div_eq_mul_inv, div_eq_mul_inv, ENNReal.mul_inv (Or.inl hc) (Or.inl hc'), mul_mul_mul_comm,
    ENNReal.mul_inv_cancel hc hc', one_mul]

Goal state after:
Module: Mathlib.Data.ENNReal.Inv

Goal state before:
pp: case inr.inl
b : ℝ≥0∞
h₀ : ∞ = 0 → b = 0
h₁ : ∞ = ∞ → b = 0
ha : ∞ ≠ 0
⊢ ∞ / (∞ / b) = b

Tactic:
simp [h₁, top_div_of_lt_top]

Goal state after:
Module: Mathlib.Topology.EMetricSpace.Defs

Goal state before:
pp: case mp
α : Type u
inst✝ : PseudoEMetricSpace α
β : Type u_2
p : β → Prop
f : β → ℝ≥0∞
hf₀ : ∀ (x : β), p x → 0 < f x
hf : ∀ (ε : ℝ≥0∞), 0 < ε → ∃ x, p x ∧ f x ≤ ε
s : Set (α × α)
⊢ (∃ i, 0 < i ∧ {p | edist p.1 p.2 < i} ⊆ s) → ∃ i, p i ∧ {p | edist p.1 p.2 ≤ f i} ⊆ s

Tactic:
rintro ⟨ε, ε₀, hε⟩
    rcases exists_between ε₀ with ⟨ε', hε'⟩
    rcases hf ε' hε'.1 with ⟨i, hi, H⟩
    exact ⟨i, hi, fun x hx => hε <| lt_of_le_of_lt (le_trans hx.out H) hε'.2⟩

Goal state after:
Module: Mathlib.Topology.EMetricSpace.Defs

Goal state before:
pp: α : Type u
inst✝ : PseudoEMetricSpace α
x y : α
ε : ℝ≥0∞
h : y ∈ eball x ε
⊢ ∃ ε' > 0, eball y ε' ⊆ eball x ε

Tactic:
by
  have : 0 < ε - edist y x := by simpa using h
  refine ⟨ε - edist y x, this, eball_subset ?_ (ne_top_of_lt h)⟩
  exact (add_tsub_cancel_of_le (mem_eball.mp h).le).le

Goal state after:
Module: Mathlib.RingTheory.DedekindDomain.Factorization

Goal state before:
pp: R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
J : Ideal R
⊢ 0 ≤ count K v ↑J

Tactic:
by_cases hJ : J = 0

Goal state after:
case pos
R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
J : Ideal R
hJ : J = 0
⊢ 0 ≤ count K v ↑J

case neg
R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
J : Ideal R
hJ : ¬J = 0
⊢ 0 ≤ count K v ↑J
Module: Mathlib.RingTheory.DedekindDomain.Factorization

Goal state before:
pp: case pos
R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
J : Ideal R
hJ : J = 0
⊢ 0 ≤ count K v ↑J

Tactic:
simp only [hJ, Submodule.zero_eq_bot, coeIdeal_bot, count_zero, le_refl]

Goal state after:
Module: Mathlib.RingTheory.DedekindDomain.Factorization

Goal state before:
pp: R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
I J : FractionalIdeal R⁰ K
hI : I ≠ 0
h : I ≤ J
⊢ count K v J ≤ count K v I

Tactic:
by_cases hJ : J = 0

Goal state after:
case pos
R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
I J : FractionalIdeal R⁰ K
hI : I ≠ 0
h : I ≤ J
hJ : J = 0
⊢ count K v J ≤ count K v I

case neg
R : Type u_1
inst✝⁴ : CommRing R
K : Type u_2
inst✝³ : Field K
inst✝² : Algebra R K
inst✝¹ : IsFractionRing R K
inst✝ : IsDedekindDomain R
v : HeightOneSpectrum R
I J : FractionalIdeal R⁰ K
hI : I ≠ 0
h : I ≤ J
hJ : ¬J = 0
⊢ count K v J ≤ count K v I
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
x y : α
ε : ℝ
⊢ y ∈ ball x ε ↔ dist y x < ε

Tactic:
mem_ball

Goal state after:
α : Type u
inst✝ : PseudoMetricSpace α
x y : α
ε : ℝ
⊢ dist y x < ε ↔ dist y x < ε
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
x : α
ε : ℝ
h : 0 ≤ ε
⊢ x ∈ closedBall x ε

Tactic:
rwa [mem_closedBall, dist_self]

Goal state after:
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
x y : α
ε : ℝ
⊢ dist y x < ε ↔ y ∈ ball x ε

Tactic:
mem_ball

Goal state after:
α : Type u
inst✝ : PseudoMetricSpace α
x y : α
ε : ℝ
⊢ dist y x < ε ↔ dist y x < ε
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
x y : α
ε₁ ε₂ : ℝ
h : ε₁ + dist x y ≤ ε₂
z : α
hz : z ∈ ball x ε₁
⊢ dist z x + dist x y < ε₁ + dist x y

Tactic:
gcongr; exact hz

Goal state after:
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
x y : α
ε₁ ε₂ : ℝ
h : ε₁ + dist x y ≤ ε₂
z : α
hz : z ∈ closedBall x ε₁
⊢ dist z x + dist x y ≤ ε₁ + dist x y

Tactic:
gcongr; exact hz

Goal state after:
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
x y : α
ε₁ ε₂ : ℝ
h : ε₁ + dist x y < ε₂
z : α
hz : z ∈ closedBall x ε₁
⊢ dist z x + dist x y ≤ ε₁ + dist x y

Tactic:
gcongr; exact hz

Goal state after:
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α✝ : Type u
β : Type v
X : Type u_1
ι : Type u_2
inst✝ : PseudoMetricSpace α✝
α : Type u_3
U : UniformSpace α
m : PseudoMetricSpace α
H : 𝓤 α = 𝓤 α
⊢ PseudoMetricSpace.toBornology = PseudoMetricSpace.toBornology

Tactic:
by
  with_reducible_and_instances rfl

Goal state after:
Module: Mathlib.Topology.MetricSpace.Pseudo.Defs

Goal state before:
pp: α✝ : Type u
β : Type v
X : Type u_1
ι : Type u_2
inst✝ : PseudoMetricSpace α✝
α : Type u_3
B : Bornology α
m : PseudoMetricSpace α
H : ∀ (s : Set α), Bornology.IsBounded s ↔ Bornology.IsBounded s
⊢ PseudoMetricSpace.toUniformSpace = PseudoMetricSpace.toUniformSpace

Tactic:
by
  with_reducible_and_instances rfl

Goal state after:
Module: Mathlib.Topology.Metrizable.Basic

Goal state before:
pp: ι : Type u_1
X✝ : Type u_2
Y : Type u_3
A : ι → Type u_4
inst✝⁴ : TopologicalSpace X✝
inst✝³ : TopologicalSpace Y
inst✝² : Finite ι
inst✝¹ : (i : ι) → TopologicalSpace (A i)
X : Type u_5
t : TopologicalSpace X
inst✝ : PseudoMetrizableSpace X
⊢ (pseudoMetrizableSpaceUniformity X).toTopologicalSpace = t

Tactic:
by
  with_reducible_and_instances rfl

Goal state after:
Module: Mathlib.Topology.MetricSpace.Pseudo.Basic

Goal state before:
pp: β : Type v
α : Type u_2
inst✝² : TopologicalSpace α
inst✝¹ : PseudoMetrizableSpace α
f : β → α
inst✝ : TopologicalSpace β
hf : IsInducing f
s : Set α
hs : IsSeparable s
this✝ : UniformSpace α := pseudoMetrizableSpaceUniformity α
this : ∀ (X : Type ?u.31) [inst : TopologicalSpace X] [h : PseudoMetrizableSpace X], (𝓤 X).IsCountablyGenerated
⊢ IsSeparable (f ⁻¹' s)

Tactic:
have : SeparableSpace s := hs.separableSpace

Goal state after:
β : Type v
α : Type u_2
inst✝² : TopologicalSpace α
inst✝¹ : PseudoMetrizableSpace α
f : β → α
inst✝ : TopologicalSpace β
hf : IsInducing f
s : Set α
hs : IsSeparable s
this✝¹ : UniformSpace α := pseudoMetrizableSpaceUniformity α
this✝ : ∀ (X : Type ?u.31) [inst : TopologicalSpace X] [h : PseudoMetrizableSpace X], (𝓤 X).IsCountablyGenerated
this : SeparableSpace ↑s
⊢ IsSeparable (f ⁻¹' s)
Module: Mathlib.Topology.EMetricSpace.Basic

Goal state before:
pp: γ : Type w
inst✝ : EMetricSpace γ
s : Set γ
hs : IsCompact s
⊢ ∃ t ⊆ s, t.Countable ∧ s = closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] t

Tactic:
rcases subset_countable_closure_of_compact hs with ⟨t, hts, htc, hsub⟩
  exact ⟨t, hts, htc, hsub.antisymm (closure_minimal hts hs.isClosed)⟩

Goal state after: