Backward and Forward Bisimulation Minimisation of Tree Automata

  • Johanna Högberg
  • Andreas Maletti
  • Jonathan May
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4783)


We improve an existing bisimulation minimisation algorithm for tree automata by introducing backward and forward bisimulations and developing minimisation algorithms for them. Minimisation via forward bisimulation is also effective for deterministic automata and faster than the previous algorithm. Minimisation via backward bisimulation generalises the previous algorithm and is thus more effective but just as fast. We demonstrate implementations of these algorithms on a typical task in natural language processing.


bisimulation tree automata minimisation natural language processing 


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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.Dept. 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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