span><span class="special">)</span>
</pre>
<p>
          where <code class="computeroutput"><span class="identifier">p</span></code> is a parser. Each
          of the arguments (a1 ... aN) can either be an immediate value, or a function,
          <code class="computeroutput"><span class="identifier">f</span></code>, with signature:
        </p>
<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">f</span><span class="special">(</span><span class="identifier">Unused</span>