Skip to main content

The ambiguity of primitive words

  • Conference paper
  • First Online:

Part of the book series: Lecture Notes in Computer Science ((LNCS,volume 775))

Abstract

A word is primitive if it is not a proper power of a shorter word. We prove that the set Q of primitive words over an alphabet is not an unambiguous context-free language. This strengthens the previous result that Q cannot be deterministic context-free. Further we show that the same holds for the set L of Lyndon words. We describe 2DPDA accepting Q and L which imply efficient decidability on the RAM model of computation and we analyse the number of comparisons required for deciding Q. Finally we give a new proof showing a related language not to be context-free, which only relies on properties of semi-linear and regular sets.

Supported by the ESPRIT Basic Research Action WG 6317: Algebraic and Syntactic Methods in Computer Science (ASMICS 2)

This is a preview of subscription content, log in via an institution.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. T. M. Apostol: Introduction to Analytic Number Theory, Springer-Verlag, New York, Berlin, Heidelberg, Tokyo (1976, 3rd printing 1986).

    Google Scholar 

  2. K.S. Booth: Lexicographically least circular substrings, Inform. Process. Lett. 10 (4) (1980) pp. 240–242.

    Google Scholar 

  3. N. Chomsky, M. P. Schützenberger: The algebraic theory of context-free languages, Computer Programming and Formal Systems (P. Brafford, D. Hirschberg eds.), North-Holland, Amsterdam (1963), pp. 118–161.

    Google Scholar 

  4. L. Comtet: Calcul pratique des coefficients de Taylor d'une fonction algébrique, L'Enseignement Mathématique 10 (1964) pp. 267–270.

    Google Scholar 

  5. S. A. Cook: Linear time simulation of deterministic two-way pushdown automata, Inf. Proc. 71, North-Holland (1972) pp. 75–80.

    Google Scholar 

  6. V. Diekert, personal communication (1993).

    Google Scholar 

  7. P. Dömösi, S. Horváth, M. Ito: Formal languages and primitive words, Publ. Math., Debrecen 42 3–4 (1993) pp. 315–321.

    Google Scholar 

  8. P. Dömösi, S. Horváth, M. Ito, L. Kászonyi, M. Katsura: Formai languages consisting of primitive words, Proc. FCT93, LNCS 710, Springer-Verlag, Berlin, Heidelberg, New York (1993) pp. 194–203.

    Google Scholar 

  9. Ph. Flajolet: Analytic models and ambiguity of context-free languages, TCS 49 (1987) pp. 283–309.

    Google Scholar 

  10. S. Ginsburg: The Mathematical Theory of Context-Free Languages, McGraw-Hill, New York (1966).

    Google Scholar 

  11. S. Ginsburg, E. H. Spanier: Bounded Algol-like languages, Trans. AMS 113 (1964) pp. 333–368.

    Google Scholar 

  12. J.-P. Haas: Theorie und Anwendungen Semilinearer Vektormengen, Universität Hamburg, Fachbereich Informatik, Bericht Nr. 130 (1987).

    Google Scholar 

  13. G. H. Hardy, E. M. Wright: An Introduction to the Theory of Numbers, Oxford University Press, London (1938, reprinted 1968).

    Google Scholar 

  14. M. A. Harrison: Introduction to Formal Language Theory, Addison-Wesley, Reading Mass. (1978).

    Google Scholar 

  15. J. E. Hopcroft, J. D. Ullman: Introduction to Automata Theory, Languages, and Computation, Addison-Wesley, Reading Mass. (1979).

    Google Scholar 

  16. C. S. Iliopoulos, W. F. Smyth: Optimal algorithms for computing the canonical form of a circular string, TCS 92 (1992) pp. 87–105.

    Google Scholar 

  17. M. Ito, M. Katsura, H. J. Shyr, S. S. Yu: Automata accepting primitive words, Semigroup Forum 37 (1988) pp. 45–50.

    Google Scholar 

  18. D. Knuth, J. Morris, V. Pratt: Fast pattern matching in strings, SIAM J. Comp. 6 (1977) pp. 323–350.

    Google Scholar 

  19. M. Lothaire: Combinatorics on Words, Addison-Wesley, Reading Mass. (1983).

    Google Scholar 

  20. R. C. Lyndon, M. P. Schützenberger: The equation a M=b N c P in a free group, Michigan Math. J. 9 (1962) pp. 289–298.

    Google Scholar 

  21. R. J. Parikh: On context-free languages, JACM 13 (1966) pp. 570–581.

    Google Scholar 

  22. H. Petersen: Remarks on the power of 2-DPDA, Universität Hamburg, Fachbereich Informatik, Bericht Nr. 162.

    Google Scholar 

  23. H. J. Shyr, G. Thierrin: Disjunctive languages and codes, Proc. FCT77, LNCS 56, Springer-Verlag, Berlin, Heidelberg, New York (1977) pp. 171–176.

    Google Scholar 

  24. R. P. Stanley: Generating functions, MAA Studies in Math. (G.-C. Rota ed.), Vol. 17: Studies in Combinatorics, MAA (1978) pp. 100–141.

    Google Scholar 

  25. R. Stearns, J. Hartmanis, P. M. Lewis II: Hierarchies of memory limited computations, in: Proc. 6th Annual Symp. on Switching Circuit Theory and Logical Design (1965) pp. 179–190.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Editor information

Patrice Enjalbert Ernst W. Mayr Klaus W. Wagner

Rights and permissions

Reprints and permissions

Copyright information

© 1994 Springer-Verlag Berlin Heidelberg

About this paper

Cite this paper

Petersen, H. (1994). The ambiguity of primitive words. In: Enjalbert, P., Mayr, E.W., Wagner, K.W. (eds) STACS 94. STACS 1994. Lecture Notes in Computer Science, vol 775. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-57785-8_181

Download citation

  • DOI: https://doi.org/10.1007/3-540-57785-8_181

  • Published:

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-57785-0

  • Online ISBN: 978-3-540-48332-8

  • eBook Packages: Springer Book Archive

Publish with us

Policies and ethics