ables.html#variables.section">section on variables</a> for more
information on valid identifiers. For example,</p>
<div class="sourceCode" id="cb207"><pre class="sourceCode stan"><code class="sourceCode stan"><span id="cb207-1"><a href="function-names.html#cb207-1" aria-hidden="true" tabindex="-1"></a><span class="dt">real</span> foo(<span class="dt">real</span> mu, <span class="dt">real</span> sigma);</span></code></pre></div>
<p>declares a function named <code>foo</code> with two argument variables of
typ