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<H2>
<BR>
2.1.2 Boolean Operations
</H2>
<P>
These are the Boolean operations, ordered by ascending priority:
<P>
<table border align="center" style="border-collapse: collapse">
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<th align="center"><b>Operation</b> </th>
<th align="left"><b>Result</b> </th>
<th align="center"><b>Notes</b> </th>
</thead>
<tbody valign='baseline'>
<tr><td align="center" valign="baseline"><code><var>x</var> or <var>y</var></code></td>
<td align="left">if <var>x</var> is false, then <var>y</var>, else <var>x</var></td>
<td align="center">(1)</td>
<tr><td align="center" valign="baseline"><code><var>x</var> and <var>y</var></code></td>
<td align="left">if <var>x</var> is false, then <var>x</var>, else <var>y</var></td>
<td align="center">(1)</td>
<tr><td align="center" valign="baseline"><code>not <var>x</var></code></td>
<td align="left">if <var>x</var> is false, then <code>1</code>, else <code>0</code></td>
<td align="center">(2)</td></tbody>
</table>
<P>
Notes:
<P>
<DL>
<DT><STRONG>(1)</STRONG></DT>
<DD>These only evaluate their second argument if needed for their outcome.
<P>
</DD>
<DT><STRONG>(2)</STRONG></DT>
<DD>"<tt class="samp">not</tt>" has a lower priority than non-Boolean operators, so
<code>not <var>a</var> == <var>b</var></code> is interpreted as <code>not (<var>a</var> ==
<var>b</var>)</code>, and <code><var>a</var> == not <var>b</var></code> is a syntax error.
<P>
</DD>
</DL>
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