| ~256 * ~128 ≤ b2i(by1) * b2i(by2), b2i(by1) < 0, b2i(by2) < 0 ⊦ b2i(by1) * b2i(by2) = s2i(i2s(b2i(by1) * b2i(by2))) |
i < 0, j < 0, i0 ≤ i, j0 < j ⊦ ¬ i0 * j0 ≤ i * j
¬(b2i(by1) < 0 ∧ b2i(by2) < 0 ∧ ~256 ≤ b2i(by1) ∧ ~128 < b2i(by2)), ~256 * ~128 ≤ b2i(by1) * b2i(by2), b2i(by1) < 0, b2i(by2) < 0 ⊦ b2i(by1) * b2i(by2) = s2i(i2s(b2i(by1) * b2i(by2)))
Used terms: b2i(by2), b2i(by1), ~128, ~256