terallayout"><a name="idp40120208-bb"></a><span class="identifier">discrete_interval</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre>
<p>Default constructor; yields an empty interval <code class="computeroutput">[0,0)</code>. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">explicit</span> <a name="idp40121392-bb"></a><span class="identifier">discrete_interval</span><span class="special">(</span><span class="keyword">cons