Abstract
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 22 2·log(L+1)·n.
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© 1989 Springer-Verlag Berlin Heidelberg
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Seidl, H. (1989). On the finite degree of ambiguity of finite tree automata. In: Csirik, J., Demetrovics, J., Gécseg, F. (eds) Fundamentals of Computation Theory. FCT 1989. Lecture Notes in Computer Science, vol 380. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-51498-8_38
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DOI: https://doi.org/10.1007/3-540-51498-8_38
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