Higher-Order Pushdown Trees Are Easy

  • Teodor Knapik
  • Damian Niwiński
  • Paweł Urzyczyn
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2303)


We show that the monadicsec ond-order theory of an infinite tree recognized by a higher-order pushdown automaton of any level is decidable. We also show that trees recognized by pushdown automata of level n coincide with trees generated by safe higher-order grammars of level n. Our decidability result extends the result of Courcelle on algebraic(pushdo wn of level 1) trees and our own result on trees of level 2.


Formal Parameter Free Variable Function Symbol Signature Constant Lambda Calculus 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2002

Authors and Affiliations

  • Teodor Knapik
    • 1
  • Damian Niwiński
    • 2
  • Paweł Urzyczyn
    • 2
  1. 1.Université de la RéunionSaint Denis Messageries Cedex 9, Réunion
  2. 2.Institute of InformaticsWarsaw UniversityWarszawaPoland

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