n BUGS, statements are executed according to the directed graphical model so that variables are always defined when needed. A side effect of the direct execution of Stan’s modeling language is that statements execute in the order in which they are written. For instance, the following Stan program, which sets <code>mu</code> before using it to sample <code>y</code>:</p>
<div class="sourceCode" id="cb1"><pre class="sourceCode stan code-with-copy"><code class="sourceCode stan"><span id="cb1-1"><a href="#cb1-