mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Data.QPF.Multivariate.Constructions.Fix

Goal state before:
pp: n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
⊢ ((P F).wMk' ∘ repr) (abs ((TypeVec.id ::: recF ((P F).wMk' ∘ repr)) <$$> (P F).wDest' ((P F).wMk a f' f))) =
    (P F).wMk' (repr (abs ((TypeVec.id ::: recF ((P F).wMk' ∘ repr)) <$$> ⟨a, (P F).appendContents f' f⟩)))

Tactic:
q.P.wDest'_wMk

Goal state after:
n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
⊢ ((P F).wMk' ∘ repr) (abs ((TypeVec.id ::: recF ((P F).wMk' ∘ repr)) <$$> ⟨a, splitFun f' f⟩)) =
    (P F).wMk' (repr (abs ((TypeVec.id ::: recF ((P F).wMk' ∘ repr)) <$$> ⟨a, (P F).appendContents f' f⟩)))
Module: Mathlib.Data.QPF.Multivariate.Constructions.Fix

Goal state before:
pp: n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
⊢ ((TypeVec.id ::: fixToW) ⊚ (P F).appendContents f' fun x ↦ ⟦f x⟧) = (TypeVec.id ::: wrepr) ⊚ (P F).appendContents f' f

Tactic:
MvPFunctor.appendContents,

Goal state after:
n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
⊢ ((TypeVec.id ::: fixToW) ⊚ splitFun f' fun x ↦ ⟦f x⟧) = (TypeVec.id ::: wrepr) ⊚ (P F).appendContents f' f
Module: Mathlib.Data.QPF.Multivariate.Constructions.Fix

Goal state before:
pp: n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
β : Type u
g₁ g₂ : Fix F α → β
h : ∀ (x : F (α ::: Fix F α)), (TypeVec.id ::: g₁) <$$> x = (TypeVec.id ::: g₂) <$$> x → g₁ (mk x) = g₂ (mk x)
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
ih : ∀ (i : (P F).last.B a), g₁ (Quot.mk (⇑(wSetoid α)) (f i)) = g₂ (Quot.mk (⇑(wSetoid α)) (f i))
⊢ ((TypeVec.id ::: g₁) ⊚ (P F).appendContents f' fun x ↦ ⟦f x⟧) =
    (TypeVec.id ::: g₂) ⊚ (P F).appendContents f' fun x ↦ ⟦f x⟧

Tactic:
MvPFunctor.appendContents,

Goal state after:
n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
β : Type u
g₁ g₂ : Fix F α → β
h : ∀ (x : F (α ::: Fix F α)), (TypeVec.id ::: g₁) <$$> x = (TypeVec.id ::: g₂) <$$> x → g₁ (mk x) = g₂ (mk x)
a : (P F).A
f' : (P F).drop.B a ⟹ α
f : (P F).last.B a → (P F).W α
ih : ∀ (i : (P F).last.B a), g₁ (Quot.mk (⇑(wSetoid α)) (f i)) = g₂ (Quot.mk (⇑(wSetoid α)) (f i))
⊢ ((TypeVec.id ::: g₁) ⊚ splitFun f' fun x ↦ ⟦f x⟧) = (TypeVec.id ::: g₂) ⊚ splitFun f' fun x ↦ ⟦f x⟧
Module: Mathlib.Data.Real.Sign

Goal state before:
pp: case inr.inr
r : ℝ
hp : 0 < r
⊢ r.sign = -1 ∨ r.sign = 0 ∨ r.sign = 1

Tactic:
exact Or.inr <| Or.inr <| sign_of_pos hp

Goal state after:
Module: Mathlib.Data.QPF.Multivariate.Constructions.Cofix

Goal state before:
pp: n : ℕ
F : TypeVec.{u} (n + 1) → Type u
q : MvQPF F
α : TypeVec.{u} n
β : Type u
g : {X : Type u} → (Cofix F α → X) → (β → X) → β → F (α ::: X)
x : β
h :
  ∀ (X Y : Type u) (f : Cofix F α → X) (f' : β → X) (k : X → Y), g (k ∘ f) (k ∘ f') x = (TypeVec.id ::: k) <$$> g f f' x
⊢ (corec₁ g x).dest = g _root_.id (corec₁ g) x

Tactic:
by
  rw [Cofix.corec₁, Cofix.dest_corec', ← h]; rfl

Goal state after:
Module: Mathlib.Data.WSeq.Basic

Goal state before:
pp: α : Type u
s : WSeq α
⊢ s.think.destruct.destruct = Sum.inr s.destruct

Tactic:
simp [destruct, think, Computation.rmap]

Goal state after:
Module: Mathlib.Data.WSeq.Relation

Goal state before:
pp: α : Type u
β : Type v
R : α → β → Prop
s : WSeq α
t : WSeq β
⊢ LiftRel R s.think t ↔ LiftRel R s t

Tactic:
liftRel_destruct_iff,

Goal state after:
α : Type u
β : Type v
R : α → β → Prop
s : WSeq α
t : WSeq β
⊢ Computation.LiftRel (LiftRelO R (LiftRel R)) s.think.destruct t.destruct ↔ LiftRel R s t
Module: Mathlib.Data.WSeq.Relation

Goal state before:
pp: α : Type u
β : Type v
R : α → β → Prop
s : WSeq α
t : WSeq β
⊢ LiftRel R s t.think ↔ LiftRel R s t

Tactic:
liftRel_destruct_iff,

Goal state after:
α : Type u
β : Type v
R : α → β → Prop
s : WSeq α
t : WSeq β
⊢ Computation.LiftRel (LiftRelO R (LiftRel R)) s.destruct t.think.destruct ↔ LiftRel R s t
Module: Mathlib.Data.WSeq.Basic

Goal state before:
pp: α : Type u
a a' : α
s' : WSeq α
c : Computation (Option (α × WSeq α))
h : some (a', s') ∈ c
x✝ : α
s✝ : WSeq α
m : (cons x✝ s✝).destruct = Computation.pure (some (a', s'))
i1 : x✝ = a'
i2 : s✝ = s'
h_a_eq_a' : a = a' ↔ some (some a) = some (some a')
o : some (some a) = some (some a') ∨ Any (fun b ↦ some (some a) = b) ↑s'
⊢ Any (fun b ↦ some (some a) = b) (some (some a') :: ↑s')

Tactic:
rcases o with e | m

Goal state after:
case inl
α : Type u
a a' : α
s' : WSeq α
c : Computation (Option (α × WSeq α))
h : some (a', s') ∈ c
x✝ : α
s✝ : WSeq α
m : (cons x✝ s✝).destruct = Computation.pure (some (a', s'))
i1 : x✝ = a'
i2 : s✝ = s'
h_a_eq_a' : a = a' ↔ some (some a) = some (some a')
e : some (some a) = some (some a')
⊢ Any (fun b ↦ some (some a) = b) (some (some a') :: ↑s')

case inr
α : Type u
a a' : α
s' : WSeq α
c : Computation (Option (α × WSeq α))
h : some (a', s') ∈ c
x✝ : α
s✝ : WSeq α
m✝ : (cons x✝ s✝).destruct = Computation.pure (some (a', s'))
i1 : x✝ = a'
i2 : s✝ = s'
h_a_eq_a' : a = a' ↔ some (some a) = some (some a')
m : Any (fun b ↦ some (some a) = b) ↑s'
⊢ Any (fun b ↦ some (some a) = b) (some (some a') :: ↑s')
Module: Mathlib.Data.Sigma.Order

Goal state before:
pp: case mpr
ι : Type u_1
α : ι → Type u_2
inst✝ : (i : ι) → LE (α i)
a b : (i : ι) × α i
⊢ (∃ h, h ▸ a.snd ≤ b.snd) → a ≤ b

Tactic:
· obtain ⟨i, a⟩ := a
    obtain ⟨j, b⟩ := b
    rintro ⟨rfl : i = j, h⟩
    exact LE.fiber _ _ _ h

Goal state after:
Module: Mathlib.Data.Sigma.Order

Goal state before:
pp: ι : Type u_1
α : ι → Type u_2
inst✝ : (i : ι) → Preorder (α i)
⊢ ∀ (a b c : (i : ι) × α i), a ≤ b → b ≤ c → a ≤ c

Tactic:
by
      rintro _ _ _ ⟨i, a, b, hab⟩ ⟨_, _, c, hbc⟩
      exact LE.fiber i a c (hab.trans hbc)

Goal state after:
Module: Mathlib.Data.Sigma.Order

Goal state before:
pp: case refine_1.left.left
ι : Type u_1
α : ι → Type u_2
inst✝¹ : Preorder ι
inst✝ : (i : ι) → Preorder (α i)
i✝ j✝ : ι
b : α i✝
a : α j✝
hji : i✝ < j✝
hij : j✝ < i✝
⊢ False

Tactic:
exact hij.not_gt hji

Goal state after:
Module: Mathlib.Data.Sigma.Order

Goal state before:
pp: ι : Type u_1
α : ι → Type u_2
inst✝³ : Preorder ι
inst✝² : (i : ι) → Preorder (α i)
inst✝¹ : ∀ (i : ι), DenselyOrdered (α i)
inst✝ : ∀ (i : ι), NoMaxOrder (α i)
⊢ ∀ (a₁ a₂ : Σₗ (i : ι), α i), a₁ < a₂ → ∃ a, a₁ < a ∧ a < a₂

Tactic:
by
    rintro ⟨i, a⟩ ⟨j, b⟩ (⟨_, _, h⟩ | ⟨_, b, h⟩)
    · obtain ⟨c, ha⟩ := exists_gt a
      exact ⟨⟨i, c⟩, right _ _ ha, left _ _ h⟩
    · obtain ⟨c, ha, hb⟩ := exists_between h
      exact ⟨⟨i, c⟩, right _ _ ha, right _ _ hb⟩

Goal state after:
Module: Mathlib.Data.Seq.Parallel

Goal state before:
pp: α : Type u
S T : WSeq (Computation α)
a : α
h1 : ∀ s ∈ S, s ~> a
H : WSeq.LiftRel Equiv S T
h2 : ∀ t ∈ T, t ~> a := (parallel_congr_lem H).mp h1
a' : α
h : a' ∈ parallel S
aa : a = a'
⊢ a' ∈ parallel T

Tactic:
rw [← aa]

Goal state after:
α : Type u
S T : WSeq (Computation α)
a : α
h1 : ∀ s ∈ S, s ~> a
H : WSeq.LiftRel Equiv S T
h2 : ∀ t ∈ T, t ~> a := (parallel_congr_lem H).mp h1
a' : α
h : a' ∈ parallel S
aa : a = a'
⊢ a ∈ parallel T
Module: Mathlib.Data.Seq.Parallel

Goal state before:
pp: α : Type u
S T : WSeq (Computation α)
a : α
h1 : ∀ s ∈ S, s ~> a
H : WSeq.LiftRel Equiv S T
h2 : ∀ t ∈ T, t ~> a := (parallel_congr_lem H).mp h1
a' : α
h : a' ∈ parallel T
aa : a = a'
⊢ a' ∈ parallel S

Tactic:
rw [← aa]

Goal state after:
α : Type u
S T : WSeq (Computation α)
a : α
h1 : ∀ s ∈ S, s ~> a
H : WSeq.LiftRel Equiv S T
h2 : ∀ t ∈ T, t ~> a := (parallel_congr_lem H).mp h1
a' : α
h : a' ∈ parallel T
aa : a = a'
⊢ a ∈ parallel S
Module: Mathlib.Dynamics.Ergodic.AddCircle

Goal state before:
pp: T : ℝ
hT : Fact (0 < T)
s : Set (AddCircle T)
ι : Type u_1
l : Filter ι
inst✝ : l.NeBot
u : ι → AddCircle T
μ : Measure (AddCircle T) := volume
hs : NullMeasurableSet s μ
hu₁ : ∀ (i : ι), u i +ᵥ s =ᵐ[μ] s
n : ι → ℕ := addOrderOf ∘ u
hu₂ : Tendsto n l atTop
hT₀ : 0 < T
hT₁ : ENNReal.ofReal T ≠ 0
h : μ s ≠ 0
d : AddCircle T
I : ι → Set (AddCircle T) := fun j ↦ closedBall d (T / (2 * ↑(n j)))
this : ∀ᶠ (j : ι) in l, μ (s ∩ I j) / μ (I j) = μ s / ENNReal.ofReal T
hd : Tendsto (fun x ↦ μ s / ENNReal.ofReal T) l (𝓝 1)
⊢ μ s = ENNReal.ofReal T

Tactic:
rwa [tendsto_const_nhds_iff, ENNReal.div_eq_one_iff hT₁ ENNReal.ofReal_ne_top] at hd

Goal state after:
Module: Mathlib.Dynamics.Ergodic.AddCircle

Goal state before:
pp: T : ℝ
hT : Fact (0 < T)
n : ℤ
hn✝ : 1 < |n|
s : Set (AddCircle T)
hs : MeasurableSet s
hs' : (fun y ↦ n • y) ⁻¹' s = s
u : ℕ → AddCircle T := fun j ↦ ↑(1 / ↑(n.natAbs ^ j) * T)
hn : 1 < n.natAbs
hu₀ : ∀ (j : ℕ), addOrderOf (u j) = n.natAbs ^ j
j : ℕ
⊢ n ^ j • u j = 0

Tactic:
rw [← addOrderOf_dvd_iff_zsmul_eq_zero, hu₀, Int.natCast_pow, Int.natCast_natAbs, ← abs_pow,
          abs_dvd]

Goal state after:
Module: Mathlib.Dynamics.Ergodic.Conservative

Goal state before:
pp: case succ.refine_2
α : Type u_1
inst✝ : MeasurableSpace α
f : α → α
μ : Measure α
hf : Conservative f μ
n : ℕ
s : Set α
hs : MeasurableSet s
hs0 : μ s ≠ 0
x : α
left✝ : x ∈ s
hx : {n | f^[n] x ∈ s}.Infinite
k : ℕ
hk : k ∈ {n | f^[n] x ∈ s}
l : ℕ
hl : l ∈ {n | f^[n] x ∈ s}
hkl : k < l
hn : k ≡ l [MOD n.succ]
m : ℕ := (l - k) / (n + 1)
this : (n + 1) * m = l - k
⊢ k ≤ l

Tactic:
exact hkl.le

Goal state after:
Module: Mathlib.Dynamics.OmegaLimit

Goal state before:
pp: τ : Type u_1
α : Type u_2
β : Type u_3
inst✝ : TopologicalSpace β
f : Filter τ
ϕ : τ → α → β
s : Set α
y : β
⊢ y ∈ ω f ϕ s ↔ ∀ n ∈ 𝓝 y, ∃ᶠ (t : τ) in f, (s ∩ ϕ t ⁻¹' n).Nonempty

Tactic:
simp_rw [frequently_iff, omegaLimit_def, mem_iInter, mem_closure_iff_nhds]
  constructor
  · intro h _ hn _ hu
    rcases h _ hu _ hn with ⟨_, _, _, ht, _, hx, rfl⟩
    exact ⟨_, ht, _, hx, by rwa [mem_preimage]⟩
  · intro h _ hu _ hn
    rcases h _ hn hu with ⟨_, ht, _, hx, hϕtx⟩
    exact ⟨_, hϕtx, _, ht, _, hx, rfl⟩

Goal state after:
Module: Mathlib.Dynamics.OmegaLimit

Goal state before:
pp: case mp
τ : Type u_1
α : Type u_2
β : Type u_3
inst✝ : TopologicalSpace β
f : Filter τ
ϕ : τ → α → β
s₁ s₂ : Set α
y : β
⊢ y ∈ ω f ϕ (s₁ ∪ s₂) → y ∈ ω f ϕ s₁ ∪ ω f ϕ s₂

pp: case mpr
τ : Type u_1
α : Type u_2
β : Type u_3
inst✝ : TopologicalSpace β
f : Filter τ
ϕ : τ → α → β
s₁ s₂ : Set α
y : β
⊢ y ∈ ω f ϕ s₁ ∪ ω f ϕ s₂ → y ∈ ω f ϕ (s₁ ∪ s₂)

Tactic:
· simp only [mem_union, mem_omegaLimit_iff_frequently, union_inter_distrib_right, union_nonempty,
      frequently_or_distrib]
    contrapose!
    simp only [← subset_empty_iff]
    rintro ⟨⟨n₁, hn₁, h₁⟩, ⟨n₂, hn₂, h₂⟩⟩
    refine ⟨n₁ ∩ n₂, inter_mem hn₁ hn₂, h₁.mono fun t ↦ ?_, h₂.mono fun t ↦ ?_⟩
    exacts [Subset.trans <| inter_subset_inter_right _ <| preimage_mono inter_subset_left,
      Subset.trans <| inter_subset_inter_right _ <| preimage_mono inter_subset_right]

Goal state after:
case mpr
τ : Type u_1
α : Type u_2
β : Type u_3
inst✝ : TopologicalSpace β
f : Filter τ
ϕ : τ → α → β
s₁ s₂ : Set α
y : β
⊢ y ∈ ω f ϕ s₁ ∪ ω f ϕ s₂ → y ∈ ω f ϕ (s₁ ∪ s₂)
Module: Mathlib.MeasureTheory.Measure.Decomposition.RadonNikodym

Goal state before:
pp: case right
α : Type u_1
m : MeasurableSpace α
μ ν : Measure α
inst✝¹ : SigmaFinite μ
inst✝ : SigmaFinite ν
p : α → Prop
h : ∀ᵐ (a : α) ∂μ, p a
⊢ ∀ᵐ (x : α) ∂μ.withDensity (ν.rnDeriv μ), μ.rnDeriv (ν.singularPart μ + μ.withDensity (ν.rnDeriv μ)) x ≠ 0 → p x

Tactic:
· have h_ac : μ.withDensity (ν.rnDeriv μ) ≪ μ := withDensity_absolutelyContinuous _ _
    rw [← ν.haveLebesgueDecomposition_add μ]
    suffices ∀ᵐx ∂μ, μ.rnDeriv ν x ≠ 0 → p x from h_ac this
    filter_upwards [h] with _ h _ using h

Goal state after:
Module: Mathlib.Dynamics.TopologicalEntropy.CoverEntropy

Goal state before:
pp: X : Type u_1
T : X → X
U : SetRel X X
F : Set X
inst✝ : UniformSpace X
F_comp : IsCompact F
F_inv : MapsTo T F F
U_uni : U ∈ 𝓤 X
V : Set (X × X)
V_uni : V ∈ 𝓤 X
V_symm : SetRel.IsSymm V
V_U : V ○ V ⊆ U
s : Finset X
s_cover : IsDynCoverOf T F V 1 ↑s
⊢ (↑(#s)).log / 1 < ⊤

Tactic:
div_one,

Goal state after:
X : Type u_1
T : X → X
U : SetRel X X
F : Set X
inst✝ : UniformSpace X
F_comp : IsCompact F
F_inv : MapsTo T F F
U_uni : U ∈ 𝓤 X
V : Set (X × X)
V_uni : V ∈ 𝓤 X
V_symm : SetRel.IsSymm V
V_U : V ○ V ⊆ U
s : Finset X
s_cover : IsDynCoverOf T F V 1 ↑s
⊢ (↑(#s)).log < ⊤
Module: Mathlib.ModelTheory.LanguageMap

Goal state before:
pp: case refine_2
L : Language
L' : Language
ϕ : L →ᴸ L'
inst✝³ : (n : ℕ) → (f : L'.Functions n) → Decidable (f ∈ Set.range fun f ↦ ϕ.onFunction f)
inst✝² : (n : ℕ) → (r : L'.Relations n) → Decidable (r ∈ Set.range fun r ↦ ϕ.onRelation r)
h : ϕ.Injective
M : Type u_1
inst✝¹ : Inhabited M
inst✝ : L.Structure M
this : L'.Structure M := ϕ.defaultExpansion M
n : ℕ
r : L.Relations n
xs : Fin n → M
⊢ RelMap (ϕ.onRelation r) xs = RelMap r xs

Tactic:
· have hr : ϕ.onRelation r ∈ Set.range fun r : L.Relations n => ϕ.onRelation r := ⟨r, rfl⟩
    refine (dif_pos hr).trans ?_
    rw [h.onRelation hr.choose_spec]

Goal state after:
Module: Mathlib.ModelTheory.Algebra.Ring.Basic

Goal state before:
pp: α : Type u_1
R : Type u_2
S : Type u_3
inst✝³ : NonAssocRing R
inst✝² : NonAssocRing S
inst✝¹ : CompatibleRing R
inst✝ : CompatibleRing S
f : R ≃[ring] S
x y : R
⊢ f.toFun (x * y) = f.toFun x * f.toFun y

Tactic:
simpa using! f.map_fun mulFunc ![x, y]

Goal state after:
Module: Mathlib.ModelTheory.Syntax

Goal state before:
pp: case func.succ
L : Language
L' : Language
M : Type w
α : Type u'
β : Type v'
γ : Type u_1
n✝ : ℕ
f : L[[γ]].Functions (n✝ + 1)
_ts✝ : Fin (n✝ + 1) → L[[γ]].Term α
ih : ∀ (a : Fin (n✝ + 1)), (_ts✝ a).constantsToVars.varsToConstants = _ts✝ a
⊢ (func f _ts✝).constantsToVars.varsToConstants = func f _ts✝

Tactic:
obtain - | f := f
        · simp [constantsToVars, varsToConstants, ih]
        · exact isEmptyElim f

Goal state after:
Module: Mathlib.ModelTheory.Encoding

Goal state before:
pp: L : Language
α : Type u'
l : List ((n : ℕ) × L.BoundedFormula α n)
⊢ listDecode (flatMap (fun φ ↦ φ.snd.listEncode) l) = l

Tactic:
suffices h : ∀ (φ : Σ n, L.BoundedFormula α n)
      (l' : List ((Σ k, L.Term (α ⊕ Fin k)) ⊕ ((Σ n, L.Relations n) ⊕ ℕ))),
      (listDecode (listEncode φ.2 ++ l')) = φ::(listDecode l') by
    induction l with
    | nil =>
      simp [listDecode]
    | cons φ l ih => rw [flatMap_cons, h φ _, ih]

Goal state after:
L : Language
α : Type u'
l : List ((n : ℕ) × L.BoundedFormula α n)
⊢ ∀ (φ : (n : ℕ) × L.BoundedFormula α n) (l' : List ((k : ℕ) × L.Term (α ⊕ Fin k) ⊕ (n : ℕ) × L.Relations n ⊕ ℕ)),
    listDecode (φ.snd.listEncode ++ l') = φ :: listDecode l'
Module: Mathlib.ModelTheory.Encoding

Goal state before:
pp: case rel.refine_1
L : Language
α : Type u'
l✝ : List ((n : ℕ) × L.BoundedFormula α n)
n φ_n φ_l : ℕ
φ_R : L.Relations φ_l
ts : Fin φ_l → L.Term (α ⊕ Fin φ_n)
l : List ((k : ℕ) × L.Term (α ⊕ Fin k) ⊕ (n : ℕ) × L.Relations n ⊕ ℕ)
h :
  ∀ (i : Fin φ_l),
    (List.map Sum.getLeft? (List.map (fun i ↦ Sum.inl ⟨⟨φ_n, rel φ_R ts⟩.fst, ts i⟩) (finRange φ_l) ++ l))[i]?.join =
      some ⟨φ_n, ts i⟩
i : Fin φ_l
⊢ cast ⋯
      (((List.map Sum.getLeft? (List.map (fun i ↦ Sum.inl ⟨φ_n, ts i⟩) (finRange φ_l) ++ l))[i]?.bind id).get ⋯).snd =
    ts i

Tactic:
obtain ⟨h1, h2⟩ := Option.eq_some_iff_get_eq.1 (h i)
      rw [cast_eq_iff_heq]
      exact (Sigma.ext_iff.1 ((Sigma.eta (Option.get _ h1)).trans h2)).2

Goal state after:
Module: Mathlib.ModelTheory.ElementarySubstructures

Goal state before:
pp: L : Language
M : Type u_1
inst✝ : L.Structure M
A : Set M
hA : MeetsDefinable A
n : ℕ
φ : L.BoundedFormula Empty (n + 1)
x : Fin n → ↥((closure L).toFun A)
a : M
⊢ φ.Realize default (Fin.snoc (Subtype.val ∘ x) a) → ∃ b, φ.Realize default (Fin.snoc (Subtype.val ∘ x) ↑b)

Tactic:
hφ

Goal state after:
L : Language
M : Type u_1
inst✝ : L.Structure M
A : Set M
hA : MeetsDefinable A
n : ℕ
φ : L.BoundedFormula Empty (n + 1)
x : Fin n → ↥((closure L).toFun A)
a : M
hφ : φ.Realize default (Fin.snoc (Subtype.val ∘ x) a)
⊢ ∃ b, φ.Realize default (Fin.snoc (Subtype.val ∘ x) ↑b)
Module: Mathlib.ModelTheory.Definability

Goal state before:
pp: M : Type w
A : Set M
L : Language
inst✝ : L.Structure M
α : Type u₁
s : Set (α → M)
φ : L[[↑A]].Formula α
hφ : s = ofPred φ.Realize
⊢ A.Definable L sᶜ

Tactic:
refine ⟨φ.not, ?_⟩

Goal state after:
M : Type w
A : Set M
L : Language
inst✝ : L.Structure M
α : Type u₁
s : Set (α → M)
φ : L[[↑A]].Formula α
hφ : s = ofPred φ.Realize
⊢ sᶜ = ofPred φ.not.Realize
Module: Mathlib.ModelTheory.Definability

Goal state before:
pp: M : Type w
A : Set M
L : Language
inst✝ : L.Structure M
α : Type u₁
s t : Set (α → M)
hs : A.Definable L s
ht : A.Definable L t
⊢ A.Definable L (s ⇨ t)

Tactic:
by rw [himp_eq]; exact ht.union hs.compl

Goal state after:
Module: Mathlib.ModelTheory.Encoding

Goal state before:
pp: L : Language
α : Type u'
inst✝¹ : Countable α
inst✝ : Countable L.Symbols
⊢ Countable (constantsOn α).Symbols

Tactic:
refine mk_le_aleph0_iff.mp ?_
  change (constantsOn α).card ≤ ℵ₀
  simpa only [card_constantsOn, mk_le_aleph0_iff]

Goal state after:
Module: Mathlib.ModelTheory.Semantics

Goal state before:
pp: L : Language
M : Type w
inst✝ : L.Structure M
r : L.Relations 2
⊢ M ⊨ r.total ↔ Std.Total fun x y ↦ RelMap r ![x, y]

Tactic:
by
  rw [total_def]
  exact forall₂_congr fun _ _ ↦ realize_sup.trans <| or_congr realize_rel₂ realize_rel₂

Goal state after:
Module: Mathlib.ModelTheory.Definability

Goal state before:
pp: M : Type u_1
L : Language
inst✝¹ : L.Structure M
α : Type u_2
A : Set M
f : (α → M) → M
p : (α → M) → Prop
g : (α → M) → M
inst✝ : DecidablePred p
hp : A.Definable L (ofPred p)
hf : DefinableFun L A f
hg : DefinableFun L A g
P : Set (Option α → M) := {w | p (w ∘ some)}
hP : A.Definable L P
⊢ DefinableFun L A fun v ↦ if p v then f v else g v

Tactic:
simp only [DefinableFun]

Goal state after:
M : Type u_1
L : Language
inst✝¹ : L.Structure M
α : Type u_2
A : Set M
f : (α → M) → M
p : (α → M) → Prop
g : (α → M) → M
inst✝ : DecidablePred p
hp : A.Definable L (ofPred p)
hf : DefinableFun L A f
hg : DefinableFun L A g
P : Set (Option α → M) := {w | p (w ∘ some)}
hP : A.Definable L P
⊢ A.Definable L (tupleGraph fun v ↦ if p v then f v else g v)
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: L : Language
M : Type w'
inst✝ : L.Structure M
κ : Cardinal.{w}
h1 : ℵ₀ ≤ κ
h2 : lift.{w, max u v} L.card ≤ lift.{max u v, w} κ
h3 : lift.{w', w} κ ≤ lift.{w, w'} #M
⊢ ∃ N, Nonempty (↑N ↪ₑ[L] M) ∧ #↑N = κ

Tactic:
obtain ⟨S, _, hS⟩ := exists_elementarySubstructure_card_eq L ∅ κ h1 (by simp) h2 h3

Goal state after:
L : Language
M : Type w'
inst✝ : L.Structure M
κ : Cardinal.{w}
h1 : ℵ₀ ≤ κ
h2 : lift.{w, max u v} L.card ≤ lift.{max u v, w} κ
h3 : lift.{w', w} κ ≤ lift.{w, w'} #M
S : L.ElementarySubstructure M
left✝ : ∅ ⊆ ↑S
hS : lift.{w, w'} #↥S = lift.{w', w} κ
⊢ ∃ N, Nonempty (↑N ↪ₑ[L] M) ∧ #↑N = κ
Module: Mathlib.RingTheory.Nullstellensatz

Goal state before:
pp: k : Type u_1
K : Type u_2
inst✝⁴ : Field k
inst✝³ : Field K
inst✝² : Algebra k K
σ : Type u_3
inst✝¹ : IsAlgClosed K
inst✝ : Finite σ
I : Ideal (MvPolynomial σ k)
hI : I.IsMaximal
⊢ ∃ x, I = vanishingIdeal k {x}

Tactic:
let : Field (MvPolynomial σ k ⧸ I) := Quotient.field I

Goal state after:
k : Type u_1
K : Type u_2
inst✝⁴ : Field k
inst✝³ : Field K
inst✝² : Algebra k K
σ : Type u_3
inst✝¹ : IsAlgClosed K
inst✝ : Finite σ
I : Ideal (MvPolynomial σ k)
hI : I.IsMaximal
this : Field (MvPolynomial σ k ⧸ I) := Quotient.field I
⊢ ∃ x, I = vanishingIdeal k {x}
Module: Mathlib.ModelTheory.Satisfiability

Goal state before:
pp: ⊢ Language.empty.infiniteTheory.ModelType

Tactic:
haveI : Language.empty.Structure ℕ := emptyStructure

Goal state after:
this : Language.empty.Structure ℕ
⊢ Language.empty.infiniteTheory.ModelType
Module: Mathlib.LinearAlgebra.FreeAlgebra

Goal state before:
pp: case inr
R : Type u
S : Type v
inst✝² : CommRing R
inst✝¹ : Ring S
inst✝ : Algebra R S
s : Set S
h✝ : Nontrivial R
⊢ Module.rank R ↥((FreeAlgebra.lift R) Subtype.val).range ≤ max #↑s ℵ₀

Tactic:
← lift_le.{max u v}

Goal state after:
case inr
R : Type u
S : Type v
inst✝² : CommRing R
inst✝¹ : Ring S
inst✝ : Algebra R S
s : Set S
h✝ : Nontrivial R
⊢ lift.{max u v, v} (Module.rank R ↥((FreeAlgebra.lift R) Subtype.val).range) ≤ lift.{max u v, v} (max #↑s ℵ₀)
Module: Mathlib.SetTheory.Cardinal.Divisibility

Goal state before:
pp: case refine_2.inr.inr.inr
a : Cardinal.{u}
ha : ℵ₀ ≤ a
b c : Cardinal.{u}
hbc : a ∣ b * c
hz : b * c ≠ 0
this : ∀ {a : Cardinal.{u}}, ℵ₀ ≤ a → ∀ (b c : Cardinal.{u}), a ∣ b * c → b * c ≠ 0 → c ≤ b → a ∣ b ∨ a ∣ c
h : ¬c ≤ b
h✝ : b ≤ c
⊢ a ∣ c ∨ a ∣ b

Tactic:
apply_assumption

Goal state after:
case refine_2.inr.inr.inr.ha
a : Cardinal.{u}
ha : ℵ₀ ≤ a
b c : Cardinal.{u}
hbc : a ∣ b * c
hz : b * c ≠ 0
this : ∀ {a : Cardinal.{u}}, ℵ₀ ≤ a → ∀ (b c : Cardinal.{u}), a ∣ b * c → b * c ≠ 0 → c ≤ b → a ∣ b ∨ a ∣ c
h : ¬c ≤ b
h✝ : b ≤ c
⊢ ℵ₀ ≤ a

case refine_2.inr.inr.inr.hbc
a : Cardinal.{u}
ha : ℵ₀ ≤ a
b c : Cardinal.{u}
hbc : a ∣ b * c
hz : b * c ≠ 0
this : ∀ {a : Cardinal.{u}}, ℵ₀ ≤ a → ∀ (b c : Cardinal.{u}), a ∣ b * c → b * c ≠ 0 → c ≤ b → a ∣ b ∨ a ∣ c
h : ¬c ≤ b
h✝ : b ≤ c
⊢ a ∣ c * b

case refine_2.inr.inr.inr.hz
a : Cardinal.{u}
ha : ℵ₀ ≤ a
b c : Cardinal.{u}
hbc : a ∣ b * c
hz : b * c ≠ 0
this : ∀ {a : Cardinal.{u}}, ℵ₀ ≤ a → ∀ (b c : Cardinal.{u}), a ∣ b * c → b * c ≠ 0 → c ≤ b → a ∣ b ∨ a ∣ c
h : ¬c ≤ b
h✝ : b ≤ c
⊢ c * b ≠ 0

case refine_2.inr.inr.inr.h
a : Cardinal.{u}
ha : ℵ₀ ≤ a
b c : Cardinal.{u}
hbc : a ∣ b * c
hz : b * c ≠ 0
this : ∀ {a : Cardinal.{u}}, ℵ₀ ≤ a → ∀ (b c : Cardinal.{u}), a ∣ b * c → b * c ≠ 0 → c ≤ b → a ∣ b ∨ a ∣ c
h : ¬c ≤ b
h✝ : b ≤ c
⊢ b ≤ c
Module: Mathlib.FieldTheory.AxGrothendieck

Goal state before:
pp: K : Type u_1
ι : Type u_2
inst✝³ : Field K
inst✝² : IsAlgClosed K
inst✝¹ : Finite ι
inst✝ : CompatibleRing K
c✝ : Set K
S : Set (ι → K)
ps : ι → MvPolynomial ι K
this : Fintype ι := Fintype.ofFinite ι
p : ℕ := ringChar K
c : Finset K
left✝ : ↑c ⊆ c✝
φ : ring.Formula (↑↑c ⊕ ι)
hφ : S = {v | φ.Realize (Sum.elim Subtype.val v)}
⊢ Set.MapsTo (fun v i ↦ (eval v) (ps i)) S S →
    Set.InjOn (fun v i ↦ (eval v) (ps i)) S → Set.SurjOn (fun v i ↦ (eval v) (ps i)) S S

Tactic:
hφ

Goal state after:
K : Type u_1
ι : Type u_2
inst✝³ : Field K
inst✝² : IsAlgClosed K
inst✝¹ : Finite ι
inst✝ : CompatibleRing K
c✝ : Set K
S : Set (ι → K)
ps : ι → MvPolynomial ι K
this : Fintype ι := Fintype.ofFinite ι
p : ℕ := ringChar K
c : Finset K
left✝ : ↑c ⊆ c✝
φ : ring.Formula (↑↑c ⊕ ι)
hφ : S = {v | φ.Realize (Sum.elim Subtype.val v)}
⊢ Set.MapsTo (fun v i ↦ (eval v) (ps i)) {v | φ.Realize (Sum.elim Subtype.val v)}
      {v | φ.Realize (Sum.elim Subtype.val v)} →
    Set.InjOn (fun v i ↦ (eval v) (ps i)) {v | φ.Realize (Sum.elim Subtype.val v)} →
      Set.SurjOn (fun v i ↦ (eval v) (ps i)) {v | φ.Realize (Sum.elim Subtype.val v)}
        {v | φ.Realize (Sum.elim Subtype.val v)}
Module: Mathlib.FieldTheory.Differential.Basic

Goal state before:
pp: F : Type u_2
inst✝⁵ : Field F
inst✝⁴ : Differential F
inst✝³ : CharZero F
K : Type u_3
inst✝² : Field K
inst✝¹ : Algebra F K
inst✝ : FiniteDimensional F K
k : K := ⋯.choose
⊢ DifferentialAlgebra F K

Tactic:
have h : F⟮k⟯ = ⊤ := (Field.exists_primitive_element F K).choose_spec

Goal state after:
F : Type u_2
inst✝⁵ : Field F
inst✝⁴ : Differential F
inst✝³ : CharZero F
K : Type u_3
inst✝² : Field K
inst✝¹ : Algebra F K
inst✝ : FiniteDimensional F K
k : K := ⋯.choose
h : F⟮k⟯ = ⊤
⊢ DifferentialAlgebra F K