| # bits = 8, int2bits(j) = bits0 + bits, 7 = # fillsgn(7, int2bits(i)), # int2bits(i) < 8, 0 ≤ i ⊦ bits0 + bits = [], lastn(8, fillsgn(8, bitsand(bits0 + bits, int2bits(i)))) = lastn(8, fillsgn(8, bitsand(bits, false ' + fillsgn(7, int2bits(i))))) |
⊦ # bits1 ≤ # bits0 ∧ bits1 ≠ [] ∧ bits1.first → bitsand(bits + bits0, bits1) = bits + bitsand(bits0, bits1)
¬(# int2bits(i) ≤ # bits ∧ int2bits(i) ≠ [] ∧ int2bits(i).first), # bits = 8, int2bits(j) = bits0 + bits, 7 = # fillsgn(7, int2bits(i)), # int2bits(i) < 8, 0 ≤ i ⊦ bits0 + bits = [], lastn(8, fillsgn(8, bitsand(bits0 + bits, int2bits(i)))) = lastn(8, fillsgn(8, bitsand(bits, false ' + fillsgn(7, int2bits(i)))))
Used simplifier rules: ⊦ int2bits(j) ≠ [];% ⊦ int2bits(j).first ↔ j < 0;% ⊦ i ≤ j → (¬ ¬ j < i ↔ false); Used terms: int2bits(i), bits, bits0