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