" data-md-toggle="toc" type="checkbox" id="__toc">
      
      
      
      <a href="./" class="md-nav__link md-nav__link--active">
        Ex. 15.7
      </a>
      
    </li>
  

            
          
        </ul>
      </nav>
    </li>
  

            
          
            
              
  
  
  
    
    <li class="md-nav__item md-nav__item--nested">
      
      
        <input class="md-nav__toggle md-toggle" data-md-toggle="__nav_2_15" type="checkbox" id="__nav_2_15" >
      
      
      
  