s the key to be looked up, while the second element (the 'J') </span>
<span class="comment">// is passed on as the attribute to the rule&lt;&gt; stored in the symbol table. </span>
<span class="comment">// Consequently, the example generates a single 'J'.</span>
<span class="identifier">BOOST_ASSERT</span><span class="special">(</span><span class="identifier">test</span><span class="special">(</span><span class="string">"J"</span><span class="special">,</span> <span class="identifier">sym</span><span class=