| # bits = # bits1, mklist(true, # bits1) = bits1 ⊦ bits2 = [], bits1 = [], bits2 + bits1 = [], bits = [], bits = lastn(# bits1, fillsgn(# bits1, bitsand(bits2 + bits1, bits))) |
⊦ # bits1 ≤ # bits0 ∧ bits1 ≠ [] ∧ ¬ bits1.first → bitsand(bits + bits0, bits1) = bitsand(bits0, bits1)
¬(# bits ≤ # bits1 ∧ bits ≠ [] ∧ ¬ bits.first), # bits = # bits1, mklist(true, # bits1) = bits1 ⊦ bits2 = [], bits1 = [], bits2 + bits1 = [], bits = [], bits = lastn(# bits1, fillsgn(# bits1, bitsand(bits2 + bits1, bits)))
# bits ≤ # bits1 ∧ bits ≠ [] ∧ ¬ bits.first, # bits = # bits1, mklist(true, # bits1) = bits1 ⊦ bits2 = [], bits1 = [], bits2 + bits1 = [], bits = [], bits = lastn(# bits1, fillsgn(# bits1, bitsand(bits1, bits)))
Used terms: bits, bits1, bits2