ed whitespace</td>
</tr>
<tr class="even">
<td align="left">isCPR</td>
<td align="left">Identify Danish CPR numbers</td>
</tr>
<tr class="odd">
<td align="left">isEmpty</td>
<td align="left">Check if the variable contains only a single value</td>
</tr>
<tr class="even">
<td align="left">isKey</td>
<td align="left">Check if the variable is a key</td>
</tr>
<tr class="odd">
<td align="left">isSingular</td>
<td align="left">Check if the variable contains only a single value</td>
</tr>
<tr class="even">
<td ali