revert q
ℕ : Type
inst✝¹ : Natural ℕ
ℤ : Type
inst✝ : Integer ℤ
q : Fraction ℤ
a b : ℤ
denominator_positive✝ : AP (Positive b)
⊢ sgn (a//b * q) ≃ sgn (a//b) * sgn q
ℕ : Type
inst✝¹ : Natural ℕ
ℤ : Type
inst✝ : Integer ℤ
a b : ℤ
denominator_positive✝ : AP (Positive b)
⊢ ∀ {q : Fraction ℤ}, sgn (a//b * q) ≃ sgn (a//b) * sgn q