Existential and Positive Theories of Equations in Graph Products

  • Volker Diekert
  • Markus Lohrey
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2285)


We prove that the existential theory of equations with normalized rational constraints in a fixed graph product of finite monoids, free monoids, and free groups is PSPACE-complete. Under certain restrictions this result also holds if the graph product is part of the input. As the second main result we prove that the positive theory of equations with recognizable constraints in graph products of finite and free groups is decidable.


Graph Product Rational Constraint Existential Theory Positive Theory Free Semigroup 
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-VerlagBerlin Heidelberg 2002

Authors and Affiliations

  • Volker Diekert
    • 1
  • Markus Lohrey
    • 1
  1. 1.Institut für InformatikUniversität StuttgartStuttgartGermany

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