 <tr>
      <th>flist</th>
      <td><p>a list of documents (<code>.doc</code>/<code>.docx</code>/<code>.pdf</code>). A full/relative
path must be provided.</p></td>
    </tr>
    <tr>
      <th>n_grams</th>
      <td><p>see <code>ngram</code> package.</p></td>
    </tr>
    <tr>
      <th>time_lim</th>
      <td><p>max time in seconds for each comparison. Defult is 1 second,
had no problem comparing documents with 50K words.</p></td>
    </tr>
    <tr>
      <th>progress_bar</th>
      <td><p>Should a prog