Web Directory

» Non-determinsitic Pushdown Automata
   A definition of NPDA with examples and a proof that NPDA accept context free languages.
   http://users.comlab.ox.ac.uk/luke.ong/teaching/moc/pda2up.pdf#search=%22pushdown%20automata%22

» Push-Down Automata
   Notes for a linguistics course defining PDA and showing their relation to context free languages.
   http://web.uvic.ca/~ling48x/ling484/notes/pda.html

» Pushdown Automata
   A site with a formal definition of PDA, some examples and a proof that PDA accept context free languages.
   http://www.cs.nott.ac.uk/~txa/g51mal.2001/notes/node29.html

» Pushdown Automata and Context Free Languages
   An article with basic definitions and a proof that the languages accepted by PDA are context free languages.
   http://homepages.fh-regensburg.de/~zar39030/in/node6.html

» Pushdown automaton
   A Wikipedia article with a definition and simple example.
   http://en.wikipedia.org/wiki/Pushdown_automaton