case h.mk.mk.mk
α : Type u_1
s✝ t s : Set α
x : α
hx : x ∈ s
y : α
hy : y ∈ s
⊢ ({ val := x, property := hx }, { val := y, property := hy }) ∈ (Prod.map (fun x => ↑x) fun x => ↑x) ⁻¹' diagonal α ↔
    ({ val := x, property := hx }, { val := y, property := hy }) ∈ diagonal ↑s
α : Type u_1
s✝ t s : Set α
⊢ (Prod.map (fun x => ↑x) fun x => ↑x) ⁻¹' diagonal α = diagonal ↑s
ext ⟨⟨x, hx⟩, ⟨y, hy⟩⟩
no goals
case h.mk.mk.mk
α : Type u_1
s✝ t s : Set α
x : α
hx : x ∈ s
y : α
hy : y ∈ s
⊢ ({ val := x, property := hx }, { val := y, property := hy }) ∈ (Prod.map (fun x => ↑x) fun x => ↑x) ⁻¹' diagonal α ↔
    ({ val := x, property := hx }, { val := y, property := hy }) ∈ diagonal ↑s
simp [Set.diagonal]