efinition of <code>foo_lpdf</code>, then there will be no difference between a <code>foo_lpdf</code> or <code>foo_lupdf</code> call.</p>
<p>The unnormalized <code>_lupdf</code> and <code>_lupmf</code> functions can only be used in the model block or in user-defined probability functions (those ending in <code>_lpdf</code> or <code>_lpmf</code>).</p>
<p>The same syntax and shorthand that works for <code>_lpdf</code> also works for log probability mass functions with suffixes <code>_lpmf</code>.</p>
<p>A func