n>
                    <span class="special">--</span><span class="identifier">s</span></code>
                    implies <code class="computeroutput"><span class="identifier">r</span> <span class="special">==</span>
                    <span class="identifier">s</span></code>. <code class="computeroutput"><span class="special">&amp;</span><span class="identifier">r</span> <span class="special">==</span>
                    <span class="special">&amp;--</span><span class="identifier">r</span></code>.
     