Primitive Words Are Unavoidable for Context-Free Languages

  • Peter Leupold
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6031)


We introduce the concept of unavoidability of languages with respect to a language class; this means that every language of the given class shares at least some word with the unavoidable language. Several examples of such unavoidabilities are presented. The most interesting one is that the set of primitive words is unavoidable for context-free languages that are not linear.


Regular Language Analogous Reasoning Primitive Root Language Class Formal Language Theory 
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© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Peter Leupold
    • 1
  1. 1.Fachbereich Elektrotechnik/Informatik, Fachgebiet Theoretische InformatikUniversität KasselKasselGermany

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