class="special">(</span><span class="special">)</span><span class="special">;</span></pre>Check if environment has entries. </li>
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<pre class="literallayout"><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <a name="idp51503408-bb"></a><span class="identifier">size</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>Get the number of variables. </l