>
</table>
</p>
<div><span style="font-size: medium">&nbsp;</span></div>
<div><span style="font-size: medium">　　基本集合运算如下：</span></div>
<p>
<table cellspacing="0" cellpadding="0" border="1" style="border-right: medium none; border-top: medium none; margin: auto auto auto 25.55pt; border-left: medium none; border-bottom: medium none; border-collapse: collapse">
    <tbody>
        <tr>
            <td valign="top" width="63" style="border-right: windowtext 1pt solid; padding-rig