2>Examples</h2>
    <div class="sourceCode"><pre class="sourceCode r"><code><span class="r-in"><span><span class="kw">if</span> <span class="op">(</span><span class="fu"><a href="has_sympy.html">has_sympy</a></span><span class="op">(</span><span class="op">)</span><span class="op">)</span><span class="op">{</span></span></span>
<span class="r-in"><span>  <span class="fu"><a href="def_sym.html">def_sym</a></span><span class="op">(</span><span class="va">x</span>, <span class="va">y</span>, <span class="va">z