| # bits % 8 = 0 ∧ bits ≠ [], n ≤ # bits / 8, # bits ≤ 8 * (n - 1) ⊦ bits = [], n = 0, fix(n, bits2bytes(bits)) = bits2bytes(fillsgn(n * 8, bits)) |
# bits % 8 = 0, # bits ≤ 8 * (n - 1), n ≤ # bits / 8 ⊦ bits = [], fix(n, bits2bytes(bits)) = bits2bytes(fillsgn(n * 8, bits)), n = 0