nteger type.<br>
            </td>
          </tr>
          <tr>
            <td style="vertical-align: top; font-family: 'Courier New',Courier,monospace; font-weight: bold;">
uint_x2_type<br>
            </td>
            <td style="vertical-align: top;">At least 2X-bit unsigned
integer type.<br>
            </td>
          </tr>
          <tr>
            <td style="vertical-align: top; font-family: 'Courier New',Courier,monospace; font-weight: bold;">
big_int_type<br>
            </td>
            <td s