refine ⟨fun H a b h₁ h₂ ↦ ?_, fun H a b _ ↦ H a b⟩
d : ℕ
inst✝ : NeZero d
I : BasicInterval
⊢ (∀ (a b : ℕ), Nat.Coprime a b → mem_S_le d ↑a ↑b → mem a b I → a * I.b₂ = b * I.a₂) ↔
    ∀ (a b : ℕ), mem_S_le d ↑a ↑b → mem a b I → a * I.b₂ = b * I.a₂
d : ℕ
inst✝ : NeZero d
I : BasicInterval
H : ∀ (a b : ℕ), Nat.Coprime a b → mem_S_le d ↑a ↑b → mem a b I → a * I.b₂ = b * I.a₂
a b : ℕ
h₁ : mem_S_le d ↑a ↑b
h₂ : mem a b I
⊢ a * I.b₂ = b * I.a₂