pushdown automaton

pushdown automaton (plural pushdown automata or pushdown automatons)

1. (computing theory) An automaton with finitely many states that can also use one unbounded stack of memory; the automaton may only push, pop, or read the top of the stack. Abbreviation: PDA.

   Synonym: pushdown

• Turing machine
• cellular automaton
• unlimited register machine
• context-free grammar