A Bit of Nondeterminism Makes Pushdown Automata Expressive and Succinct

  title={A Bit of Nondeterminism Makes Pushdown Automata Expressive and Succinct},
  author={Shibashis Guha and Isma{\"e}l Jecker and Karoliina Lehtinen and Martin Zimmermann},
We study the expressiveness and succinctness of good-for-games pushdown automata (GFG-PDA) over finite words, that is, pushdown automata whose nondeterminism can be resolved based on the run constructed so far, but independently of the remainder of the input word. We prove that GFG-PDA recognise more languages than deterministic PDA (DPDA) but not all context-free languages (CFL). This class is orthogonal to unambiguous CFL. We further show that GFG-PDA can be exponentially more succinct than… 

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