| 8 ≠ # fillsgn(8, int2bits(j).rest), j < ~128, 256 * i0 + j < ~128, ~256 < j, j < 0, 256 * i0 + j < 0, i0 < 0 ⊦ b2i(i2b(bits2int(lastn(8, int2bits(i0 - 1) + fillsgn(8, int2bits(j).rest))))) = 256 + j |
i0 < 0, 256 * i0 + j < 0, j < 0, ~256 < j, 256 * i0 + j < ~128, j < ~128 ⊦ 8 = # fillsgn(8, int2bits(j).rest), b2i(i2b(bits2int(lastn(8, int2bits(i0 - 1) + fillsgn(8, int2bits(j).rest))))) = 256 + j
Used simplifier rules: ⊦ i + j = j + i;% ⊦ i + j + i0 = (i + j) + i0;% ⊦ i * j = j * i;