| bitsand(sgn(lastn(8, fillsgn(8, int2bits(i)))), int2bits(j)) ≠ [], lastn(8, fillsgn(8, int2bits(i))) ≠ [] ⊦ band(i, j) = bits2int(bitsand(sgn(lastn(8, fillsgn(8, int2bits(i)))), int2bits(j))), b2i(i2b(band(i, j))) = bits2int(lastn(8, fillsgn(8, sgn(bitsand(sgn(lastn(8, fillsgn(8, int2bits(i)))), int2bits(j)))))) |
⊦ bits ≠ [] ∧ bits0 ≠ [] → sgn(bitsand(sgn(bits), bits0)) = sgn(bitsand(bits, bits0))
lastn(8, fillsgn(8, int2bits(i))) ≠ [] ∧ int2bits(j) ≠ [], bitsand(sgn(lastn(8, fillsgn(8, int2bits(i)))), int2bits(j)) ≠ [], lastn(8, fillsgn(8, int2bits(i))) ≠ [] ⊦ band(i, j) = bits2int(bitsand(sgn(lastn(8, fillsgn(8, int2bits(i)))), int2bits(j))), b2i(i2b(band(i, j))) = bits2int(lastn(8, fillsgn(8, sgn(bitsand(lastn(8, fillsgn(8, int2bits(i))), int2bits(j))))))
Used simplifier rules: ⊦ lastn(n, bits) = [] ↔ n = 0;% ⊦ int2bits(j) ≠ []; Used terms: int2bits(j), lastn(8, fillsgn(8, int2bits(i)))