1  a (c)
       2       unsigned char c;
       3  {
       4    unsigned u = c;
       5    if ((int)u < 0)
       6      return 1;
       7    else
       8      return 0;
       9  }
      10  
      11  b (x, y)
      12       unsigned x, y;
      13  {
      14    x /= y;
      15    if ((int)x < 0)
      16      return 1;
      17    else
      18      return 0;
      19  }