case mp
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
⊢ WellFounded (Quotient.lift₂ r H) → WellFounded r

case mpr
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
⊢ WellFounded r → WellFounded (Quotient.lift₂ r H)
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
⊢ WellFounded (Quotient.lift₂ r H) ↔ WellFounded r
constructor
no goals
case mp
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
⊢ WellFounded (Quotient.lift₂ r H) → WellFounded r
exact RelHomClass.wellFounded (Quotient.mkRelHom H)
case mpr
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
wf : WellFounded r
q : Quotient inst✝
⊢ Acc (Quotient.lift₂ r H) q
case mpr
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
⊢ WellFounded r → WellFounded (Quotient.lift₂ r H)
refine' fun wf => ⟨fun q => _⟩
case mpr.intro
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
wf : WellFounded r
a : α
⊢ Acc (Quotient.lift₂ r H) (Quotient.mk inst✝ a)
case mpr
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
wf : WellFounded r
q : Quotient inst✝
⊢ Acc (Quotient.lift₂ r H) q
obtain ⟨a, rfl⟩ := q.exists_rep
no goals
case mpr.intro
α : Type u_1
β : Type ?u.45658
γ : Type ?u.45661
δ : Type ?u.45664
r✝ : α → α → Prop
s : β → β → Prop
t : γ → γ → Prop
u : δ → δ → Prop
inst✝ : Setoid α
r : α → α → Prop
H : ∀ (a₁ b₁ a₂ b₂ : α), a₁ ≈ a₂ → b₁ ≈ b₂ → r a₁ b₁ = r a₂ b₂
wf : WellFounded r
a : α
⊢ Acc (Quotient.lift₂ r H) (Quotient.mk inst✝ a)
exact acc_lift₂_iff.2 (wf.apply a)