special>(</span><span class=literal>'b'</span><span class=special>),
    </span><span class=identifier>c </span><span class=special>= </span><span class=identifier>ch_p</span><span class=special>(</span><span class=literal>'c'</span><span class=special>)  </span><span class=comment>// OK</span></code></pre>
<h3> The start subrule</h3>
<p>Unlike rules, parsing proceeds from the start subrule. The first (topmost) 
  subrule in a group of subrules is called the <b>start subrule</b>. In our example 
  above, <t