Theorem: FirstOrder.Language.Ultraproduct.boundedFormula_realize_cast
File: Mathlib/ModelTheory/Ultraproducts.lean

Proof steps:
state_before: α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
φ : L.BoundedFormula β n
x : β → (a : α) → M a
v : Fin n → (a : α) → M a
⊢ (φ.Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, φ.Realize (fun i => x i a) fun i => v i a
state_after: α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
φ : L.BoundedFormula β n
x : β → (a : α) → M a
v : Fin n → (a : α) → M a
this : Setoid ((a : α) → M a) := (↑u).productSetoid M
⊢ (φ.Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, φ.Realize (fun i => x i a) fun i => v i a
tactic: letI := (u : Filter α).productSetoid M
state_before: α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
φ : L.BoundedFormula β n
x : β → (a : α) → M a
v : Fin n → (a : α) → M a
this : Setoid ((a : α) → M a) := (↑u).productSetoid M
⊢ (φ.Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, φ.Realize (fun i => x i a) fun i => v i a
state_after: case falsum
α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
x : β → (a : α) → M a
this : Setoid ((a : α) → M a) := (↑u).productSetoid M
n✝ : ℕ
v : Fin n✝ → (a : α) → M a
⊢ (BoundedFormula.falsum.Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, BoundedFormula.falsum.Realize (fun i => x i a) fun i => v i a

case equal
α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
x : β → (a : α) → M a
this : Setoid ((a : α) → M a) := (↑u).productSetoid M
n✝ : ℕ
t₁✝ t₂✝ : L.Term (β ⊕ Fin n✝)
v : Fin n✝ → (a : α) → M a
⊢ ((BoundedFormula.equal t₁✝ t₂✝).Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, (BoundedFormula.equal t₁✝ t₂✝).Realize (fun i => x i a) fun i => v i a

case rel
α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
x : β → (a : α) → M a
this : Setoid ((a : α) → M a) := (↑u).productSetoid M
n✝ l✝ : ℕ
R✝ : L.Relations l✝
ts✝ : Fin l✝ → L.Term (β ⊕ Fin n✝)
v : Fin n✝ → (a : α) → M a
⊢ ((BoundedFormula.rel R✝ ts✝).Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, (BoundedFormula.rel R✝ ts✝).Realize (fun i => x i a) fun i => v i a

case imp
α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
x : β → (a : α) → M a
this : Setoid ((a : α) → M a) := (↑u).productSetoid M
m : ℕ
f₁✝ f₂✝ : L.BoundedFormula β m
ih :
  ∀ (v : Fin m → (a : α) → M a),
    (f₁✝.Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
      ∀ᶠ (a : α) in ↑u, f₁✝.Realize (fun i => x i a) fun i => v i a
ih' :
  ∀ (v : Fin m → (a : α) → M a),
    (f₂✝.Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
      ∀ᶠ (a : α) in ↑u, f₂✝.Realize (fun i => x i a) fun i => v i a
v : Fin m → (a : α) → M a
⊢ ((f₁✝ ⟹ f₂✝).Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, (f₁✝ ⟹ f₂✝).Realize (fun i => x i a) fun i => v i a

case all
α : Type u_1
M : α → Type u_2
u : Ultrafilter α
L : Language
inst✝¹ : (a : α) → L.Structure (M a)
inst✝ : ∀ (a : α), Nonempty (M a)
β : Type u_3
n : ℕ
x : β → (a : α) → M a
this : Setoid ((a : α) → M a) := (↑u).productSetoid M
k : ℕ
φ : L.BoundedFormula β (k + 1)
ih :
  ∀ (v : Fin (k + 1) → (a : α) → M a),
    (φ.Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
      ∀ᶠ (a : α) in ↑u, φ.Realize (fun i => x i a) fun i => v i a
v : Fin k → (a : α) → M a
⊢ ((∀'φ).Realize (fun i => Quotient.mk' (x i)) fun i => Quotient.mk' (v i)) ↔
    ∀ᶠ (a : α) in ↑u, (∀'φ).Realize (fun i => x i a) fun i => v i a
tactic: induction' φ with _ _ _ _ _ _ _ _ m _ _ ih ih' k φ ih