| ¬ 8 ≤ # bitsand(bits1, bits), int2bits(j) = bits2 + bits1, # bits1 = 8, int2bits(i) = bits0 + bits, # bits = 8, bits.first, 8 ≤ # bits2 + # bitsand(bits1, bits) ⊦ lastn(8, bitsand(bits1, bits)) = lastn(8, bits2 + bitsand(bits1, bits)), bits2 + bits1 = [], bits2 = [], bits0 = [], bits1 = [], bits = [], # bits2 + # bitsand(bits1, bits) = 0 |
# bits = 8, int2bits(i) = bits0 + bits, # bits1 = 8, int2bits(j) = bits2 + bits1, # bitsand(bits1, bits) < 8, 8 ≤ # bits2 + # bitsand(bits1, bits), bits.first ⊦ bits = [], bits1 = [], bits0 = [], bits2 = [], bits2 + bits1 = [], lastn(8, bitsand(bits1, bits)) = lastn(8, bits2 + bitsand(bits1, bits))
Used simplifier rules: ⊦ m + n = n + m;% ⊦ (m + n0) + n1 = m + n0 + n1;% ⊦ # bits = 0 ↔ bits = [];% ⊦ m < m + n ↔ n ≠ 0;% ⊦ m < n → n ≠ 0;% ⊦ m < n ∧ n = n0 → m < n0; (forward)% ⊦ m < n ∧ n ≤ n0 → m < n0; (forward)% ⊦ ¬ m ≤ n ↔ n < m;