| # bits1 = # bits1 ⊦ bits1 = [], bits2 + bits1 = [], bits0 = [], bits1 = lastn(# bits1, fillsgn(# bits1, bitsand(bits2 + bits1, bits0))), true ∈ bits1 |
⊦ bits1 = [], bits2 + bits1 = [], bits0 = [], bits1 = lastn(# bits1, fillsgn(# bits1, bitsand(bits2 + bits1, bits0))), true ∈ bits1