rrently flagged with an
  error at compile time (the UML specifications explicitly allow them while
  Harel does not mention them at all). I decided to not support them because
  I have erroneously tried to implement such a transition several times but
  have never come across a situation where it would make any sense. If you
  need to make such transitions, please do let me know!</p>
  <hr>

  <p><a href="http://validator.w3.org/check?uri=referer"><img border="0" src=
  "../../../doc/images/valid-html401.p