exact finite_comprehension₁!
  this
  (⟨s, fun x ↦ by rintro ⟨y, hy⟩; exact lt_of_le_of_lt (le_pair_left x y) (lt_of_mem hy)⟩)
M : Type u_1
inst✝⁵ : Zero M
inst✝⁴ : One M
inst✝³ : Add M
inst✝² : Mul M
inst✝¹ : LT M
inst✝ : M ⊧ₘ* 𝐈𝚺₁
s : M
this : 𝚺₁-Predicate fun x => ∃ y, ⟪x, y⟫ ∈ s
⊢ ∃! d, ∀ (x : M), x ∈ d ↔ ∃ y, ⟪x, y⟫ ∈ s
no goals