 be used as shorthand for</p>
<pre><code>target += foo_lpdf(y | theta1, ..., thetaN);</code></pre>
<p>As with the built-in functions, the suffix <code>_lpdf</code> is dropped and
the first argument moves to the left of the sampling symbol (<code>~</code>)
in the sampling statement.</p>
<p>Functions ending in <code>_lpmf</code> (for probability mass functions),
behave exactly the same way. The difference is that the first
argument of a density function (<code>_lpdf</code>) must be continuous (not
an integer 