 <code class="computeroutput"><span class="identifier">a</span><span class="special">:</span>
                    <span class="identifier">A</span><span class="special">,</span>
                    <span class="identifier">b</span><span class="special">:</span>
                    <span class="identifier">Unused</span> <span class="special">--&gt;</span>
                    <span class="special">(</span><span class="identifier">a</span>
                    <span class="special">&gt;&gt;</span> <span class="