How to Remove the Look-Ahead of Top-Down Tree Transducers

  • Joost Engelfriet
  • Sebastian Maneth
  • Helmut Seidl
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8633)


For a top-down tree transducer with regular look-ahead we introduce the notion of difference bound, which is a number bounding the difference in output height for any two look-ahead states of the transducer. We present an algorithm that, for a given transducer with a known difference bound, decides whether it is equivalent to a transducer without regular look-ahead, and constructs such a transducer if the answer is positive. All transducers are total and deterministic.


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Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  • Joost Engelfriet
    • 1
  • Sebastian Maneth
    • 2
  • Helmut Seidl
    • 3
  1. 1.LIACSLeiden UniversityThe Netherlands
  2. 2.School of InformaticsUniversity of EdinburghUnited Kingdom
  3. 3.Institut für InformatikTechnische Universität MünchenGermany

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