revert p₂
ℕ : Type
inst✝² : Natural ℕ
ℤ : Type
inst✝¹ : Integer ℤ
p₂ : Fraction ℤ
inst✝ : AP (p₂ ≄ 0)
a b : ℤ
denominator_positive✝ : AP (Positive b)
⊢ ∀ [inst : AP (a//b ≄ 0)], a//b ≃ p₂ → (a//b)⁻¹ ≃ p₂⁻¹
ℕ : Type
inst✝¹ : Natural ℕ
ℤ : Type
inst✝ : Integer ℤ
a b : ℤ
denominator_positive✝ : AP (Positive b)
⊢ ∀ {p₂ : Fraction ℤ} [inst : AP (p₂ ≄ 0)] [inst_1 : AP (a//b ≄ 0)], a//b ≃ p₂ → (a//b)⁻¹ ≃ p₂⁻¹