title: How do i truncate a post (HTML/Markdown) but not give invalid markup
body: <p>is there a way i can truncate a post. eg. create a blog summary. while not breaking the markup? </p>
  
  <ul>
  <li>1st i am thinking of HTML</li>
  <li>if that can be done, how do i work on markdown posts </li>
  </ul>
  
  <p>i use PHP/Zend Framework/MySQL/Doctrine2</p>