j ≠ 0 ⊦ ~ abs(i) ≤ i / j ∧ i / j ≤ abs(i)
~ abs(b2i(by1)) ≤ b2i(by1) / i ∧ b2i(by1) / i ≤ abs(b2i(by1)) ⊦ i = ~1, i = 0, b2i(by1) / i = b2i(i2b(b2i(by1) / i))
Used terms: i, b2i(by1)