have : sgn (n——m) ≃ 0 := this
ℕ : Type
inst✝ : Natural ℕ
n m : ℕ
x✝ : n——m ≃ 0
this✝² : n ≃ m
this✝¹ : compare n m = Ordering.eq
this✝ : ord_sgn (compare n m) ≃ ord_sgn Ordering.eq
this : ord_sgn (compare n m) ≃ 0
⊢ (n——m).sgn ≃ 0
ℕ : Type
inst✝ : Natural ℕ
n m : ℕ
x✝ : n——m ≃ 0
this✝³ : n ≃ m
this✝² : compare n m = Ordering.eq
this✝¹ : ord_sgn (compare n m) ≃ ord_sgn Ordering.eq
this✝ : ord_sgn (compare n m) ≃ 0
this : (n——m).sgn ≃ 0
⊢ (n——m).sgn ≃ 0