| # bits < n ⊦ lastn(n, fillsgn(n, bitsand(sgn(lastn(n, fillsgn(n, bits))), bits0))) = lastn(n, fillsgn(n, bitsand(bits, bits0))), bits0 = [], bits = [] |
⊦ n = # bits → lastn(n, bits) = bits
n ≠ # fillsgn(n, bits), # bits < n ⊦ lastn(n, fillsgn(n, bitsand(sgn(lastn(n, fillsgn(n, bits))), bits0))) = lastn(n, fillsgn(n, bitsand(bits, bits0))), bits0 = [], bits = []
n = # fillsgn(n, bits), # bits < n ⊦ lastn(n, fillsgn(n, bitsand(sgn(fillsgn(n, bits)), bits0))) = lastn(n, fillsgn(n, bitsand(bits, bits0))), bits0 = [], bits = []
Used terms: fillsgn(n, bits), n