| int2bits(i) = bits0 + bits, # bits = 8, j < 0, # int2bits(j) < 8 ⊦ bitsand(bits, int2bits(j)) = [], lastn(8, fillsgn(8, bits0 + bitsand(bits, int2bits(j)))) = lastn(8, fillsgn(8, bitsand(bits, int2bits(j)))) |
⊦ n ≤ # bits → fillsgn(n, bits) = bits
¬ 8 ≤ # bitsand(bits, int2bits(j)), int2bits(i) = bits0 + bits, # bits = 8, j < 0, # int2bits(j) < 8 ⊦ bitsand(bits, int2bits(j)) = [], lastn(8, fillsgn(8, bits0 + bitsand(bits, int2bits(j)))) = lastn(8, fillsgn(8, bitsand(bits, int2bits(j))))
8 ≤ # bitsand(bits, int2bits(j)), int2bits(i) = bits0 + bits, # bits = 8, j < 0, # int2bits(j) < 8 ⊦ bitsand(bits, int2bits(j)) = [], lastn(8, fillsgn(8, bits0 + bitsand(bits, int2bits(j)))) = lastn(8, bitsand(bits, int2bits(j)))
Used terms: bitsand(bits, int2bits(j)), 8