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Simulations of Weighted Tree Automata

  • Zoltán Ésik
  • Andreas Maletti
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6482)

Abstract

Simulations of weighted tree automata (wta) are considered. It is shown how such simulations can be decomposed into simpler functional and dual functional simulations also called forward and backward simulations. In addition, it is shown in several cases (fields, commutative rings, Noetherian semirings, semiring of natural numbers) that all equivalent wta M and N can be joined by a finite chain of simulations. More precisely, in all mentioned cases there is a single wta that simulates both M and N. Those results immediately yield decidability of equivalence provided that the semiring is finitely (and effectively) presented.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Zoltán Ésik
    • 1
  • Andreas Maletti
    • 2
  1. 1.Department of Computer ScienceUniversity of SzegedSzegedHungary
  2. 2.Departament de Filologies RomàniquesUniversitat Rovira i VirgiliTarragonaSpain

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