31.
        </li>
        <li>
          <a href = "p31_r8vec.m">p31_r8vec.m</a>, 
          sets or gets R8VEC parameters for problem 31.
        </li>
        <li>
          <a href = "p31_region.m">p31_region.m</a>, 
          returns the region type for problem 31.
        </li>
        <li>
          <a href = "p31_title.m">p31_title.m</a>, 
          prints a title for problem 31.
        </li>
        <li>
          <a href = "p32_default.m">p32_default.m</a>, 
          sets default values for probl