| # bits = 16 + n0, n0 % 8 = 0, ∀ bits0. # bits0 < (n0 + 8) + 8 → true → # bits0 % 8 = 0 ∧ 8 < # bits0 → bits2bytes(bits0) = bits2bytes(firstn(8, bits0)) + bits2bytes(restn(8, bits0)) ⊦ n0 = 0, bits = [], bits2bytes(restn(8, firstn(n0 + 8, bits))) + i2b(bits2int(lastn(8, bits))) ' = bits2bytes(firstn(n0, restn(8, bits))) + i2b(bits2int(lastn(8, restn(8, bits)))) ' |
⊦ m + n ≤ # bits → lastn(m, restn(n, bits)) = lastn(m, bits)
8 + 8 ≤ # bits, # bits = 16 + n0, n0 % 8 = 0, ∀ bits0. # bits0 < (n0 + 8) + 8 → true → # bits0 % 8 = 0 ∧ 8 < # bits0 → bits2bytes(bits0) = bits2bytes(firstn(8, bits0)) + bits2bytes(restn(8, bits0)) ⊦ n0 = 0, bits = [], bits2bytes(restn(8, firstn(n0 + 8, bits))) + i2b(bits2int(lastn(8, bits))) ' = bits2bytes(firstn(n0, restn(8, bits))) + i2b(bits2int(lastn(8, bits))) '
Used simplifier rules: ⊦ ¬ m ≤ n ↔ n < m;% ⊦ m < n ∧ m = n0 → n0 < n; (forward)% ⊦ m < n → n ≠ 0; (forward)% ⊦ ¬ m + n < m;% ⊦ (m + n0) + n1 = m + n0 + n1;% ⊦ m + n = n + m; Used terms: bits, 8, 8