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Acta Informatica

, Volume 26, Issue 6, pp 527–542 | Cite as

On the finite degree of ambiguity of finite tree automata

  • Helmut Seidl
Article

Summary

The degree of ambiguity of a finite tree automaton A, da(A), is the maximal number of different accepting computations of A for any possible input tree. We show: it can be decided in polynomial time whether or not da(A)<∞. We give two criteria characterizing an infinite degree of ambiguity and derive the following fundamental properties of an finite tree automaton A with n states and rank L>1 having a finite degree of ambiguity: for every input tree t there is a input tree t1 of depth less than 22n·n! having the same number of accepting computations; the degree of ambiguity of A is bounded by 222·log(L+1)·n.

Keywords

Information System Operating System Data Structure Communication Network Information Theory 
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 1989

Authors and Affiliations

  • Helmut Seidl
    • 1
  1. 1.Fachbereich InformatikUniversität des SaarlandesSaarbrückenFederal Republic of Germany

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