0;</b></p>
<div class="variablelist"><dl class="variablelist">
<dt><span class="term"><code class="function">extent_range(index start, index finish)</code></span></dt>
<dd><p>  This constructor defines the half open interval
<code class="literal">[start,finish)</code>. The expression
<code class="literal">finish</code> must be greater than <code class="literal">start</code>.
</p></dd>
<dt><span class="term"><code class="function">extent_range(index finish)</code></span></dt>
<dd><p>This constructor defines 