                                 <span class="identifier">e</span>  <span class="special">|</span>     <span class="identifier">s</span>              <span class="identifier">e</span>  <span class="special">|</span>             <span class="identifier">S1</span> <span class="identifier">S2</span> <span class="identifier">S3</span>      
                                   <span class="identifier">b</span>  <span class="special">|</span>       <span class="identifier">m</span>            <span class="identifi