ex="-1" role="main">
          <div class="page-inner">

            <section class="normal" id="section-">

<div>
This is an old version, <a href="https://mc-stan.org/docs/reference-manual/user-functions.html#function-names">view current version</a>.
</div>
<div id="function-names" class="section level2" number="9.2">
<h2><span class="header-section-number">9.2</span> Function names</h2>
<p>The rules for function naming and function-argument naming are the
same as for other variables; see the <a href="vari