exact this
ℕ : Type
inst✝ : Natural ℕ
s : Difference ℕ
n m k j : ℕ
x✝¹ : (n——m).sgn ≃ s
x✝ : (k——j).sgn ≃ s
this✝⁴ : ord_sgn (compare n m) ≃ s
this✝³ : ord_sgn (compare k j) ≃ s
this✝² : ord_sgn (compare n m) ≃ ord_sgn (compare k j)
this✝¹ : compare n m = compare k j
this✝ : compare (n + k) (m + j) = compare k j
this : (n——m + k——j).sgn ≃ s
⊢ (n——m + k——j).sgn ≃ s
no goals