Bisimulation Minimisation for Weighted Tree Automata

  • Johanna Högberg
  • Andreas Maletti
  • Jonathan May
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4588)


We generalise existing forward and backward bisimulation minimisation algorithms for tree automata to weighted tree automata. The obtained algorithms work for all semirings and retain the time complexity of their unweighted variants for all additively cancellative semirings. On all other semirings the time complexity is slightly higher (linear instead of logarithmic in the number of states). We discuss implementations of these algorithms on a typical task in natural language processing.


Time Complexity Language Model Natural Language Processing Minimisation Algorithm Tree Representation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • Johanna Högberg
    • 1
  • Andreas Maletti
    • 2
  • Jonathan May
    • 3
  1. 1.Department of Computing Science, Umeå University, S–90187 UmeåSweden
  2. 2.Faculty of Computer Science, Technische Universität Dresden, D–01062 DresdenGermany
  3. 3.Information Sciences Institute, University of Southern California, Marina Del Rey, CA 90292 

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