have : Positive (-b) := Integer.sgn_positive.mpr ‹sgn (-b) ≃ 1›
ℚ : Type
inst✝ : Rational ℚ
x : ℚ
x✝ : Positive x
a b : Integer.Impl.Difference ℕ
b_nonzero✝ : Nonzero b
x_eqv : x ≃ Rational.from_integer a / Rational.from_integer b
this✝⁴ : x ≃ Rational.from_integer a / Rational.from_integer b
this✝³ : sgn a * sgn b ≃ 1
left✝ : Integer.Sqrt1 (sgn b)
right✝ : sgn a ≃ sgn b
this✝² : sgn b ≃ 1 ∨ sgn b ≃ -1
h✝ : sgn b ≃ -1
this✝¹ : sgn (-b) ≃ 1
this✝ : sgn (-a) ≃ 1
this : Positive (-a)
⊢ AltPositive x
ℚ : Type
inst✝ : Rational ℚ
x : ℚ
x✝ : Positive x
a b : Integer.Impl.Difference ℕ
b_nonzero✝ : Nonzero b
x_eqv : x ≃ Rational.from_integer a / Rational.from_integer b
this✝⁵ : x ≃ Rational.from_integer a / Rational.from_integer b
this✝⁴ : sgn a * sgn b ≃ 1
left✝ : Integer.Sqrt1 (sgn b)
right✝ : sgn a ≃ sgn b
this✝³ : sgn b ≃ 1 ∨ sgn b ≃ -1
h✝ : sgn b ≃ -1
this✝² : sgn (-b) ≃ 1
this✝¹ : sgn (-a) ≃ 1
this✝ : Positive (-a)
this : Positive (-b)
⊢ AltPositive x