Pushdown automaton, self-made
<ul><li><a href="//commons.wikimedia.org/wiki/File:Kellerautomat.png" title="File:Kellerautomat.png">Kellerautomat.png</a>: <a href="https://de.wikipedia.org/wiki/User:Martin_Hampl" class="extiw" title="de:User:Martin Hampl">Martin Hampl</a> / * derivative work <a href="//commons.wikimedia.org/w/index.php?title=User:N-regen&amp;action=edit&amp;redlink=1" class="new" title="User:N-regen (page does not exist)">n-regen</a></li></ul>
2010-04-29 12:57
<ul><li><a href="//commons.wikimedia.org/wiki/File:Kellerautomat.png" title="File:Kellerautomat.png">Kellerautomat.png</a></li></ul>