nit_normal_lpdf(<span class="dt">real</span> y);</span></code><button title="Copy to Clipboard" class="code-copy-button"><i class="bi"></i></button></pre></div>
<p>declares a function named <code>unit_normal_lpdf</code> that consumes a single real-valued input and produces a real-valued output. Declaring a function without a definition is only really useful when using an extension which supplies the definition in C++ rather than in the Stan code itself. How exactly this can be accomplished will differ depen