revert p
ℕ : Type
inst✝¹ : Natural ℕ
ℤ : Type
inst✝ : Integer ℤ
p q r : Fraction ℤ
⊢ q.denominator ≄ 0 → p ≃ q → q ≃ r → p ≃ r
ℕ : Type
inst✝¹ : Natural ℕ
ℤ : Type
inst✝ : Integer ℤ
q r : Fraction ℤ
⊢ ∀ {p : Fraction ℤ}, q.denominator ≄ 0 → p ≃ q → q ≃ r → p ≃ r