title: Can all recursive functions be re-written as tail-recursions?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/1888702/are-there-problems-that-cannot-be-written-using-tail-recursion">Are there problems that cannot be written using tail recursion?</a>  </p>
  </blockquote>
  
  
  
  <p>From my understanding, tail recursion is an optimization you can use when a recursive call does not need information from the recursive calls that it will spam. </p>
  
  <p>Is it possible then to implement all recursive functions using tail-recursion? What about something like DFS, where you need the innermost child to return before the parent can?</p>