Characterizing unambiguous augmented pushdown automata by circuits

  • Klaus-Jörn Lange
  • Peter Rossmanith
Part of the Lecture Notes in Computer Science book series (LNCS, volume 452)


The notions of weak and strong unambiguity of augmented push-down automata are considered and related to unambiguities of circuits. In particular we exhibit circuit classes exactly characterizing polynomially time bounded unambiguous augmented push-down automata.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    A. K. Chandra, D. Kozen, and L. Stockmeyer. Alternation. J. ACM, 28:114–133, 1981.Google Scholar
  2. [2]
    S. A. Cook. Characterizations of pushdown machines in terms of time-bounded computers. J. ACM, 18:4–18, 1971.Google Scholar
  3. [3]
    S. A. Cook. A taxonomy of problems with fast parallel algorithms. Inform. and Control, 64:2–22, 1985.Google Scholar
  4. [4]
    P. Dymond and W. L. Ruzzo. Parallel RAMs with owned global memory and deterministic language recognition. In Proc. of 13th ICALP, number 226 in LNCS, pages 95–104. Springer, 1987.Google Scholar
  5. [5]
    K.-J. Lange. Unambiguity of circuits. To appear in Proc. of Structure in Complexity Conf., 1990.Google Scholar
  6. [6]
    W. L. Ruzzo. On uniform circuit complexity. J. Comput. Syst. Sci., 22:365–338, 1981.Google Scholar
  7. [7]
    W. L. Ruzzo. Tree-size bounded alternation. J. Comput. Syst. Sci., 21:218–235, 1980.Google Scholar
  8. [8]
    W. Rytter. Parallel time O(log n) recognition of unambiguous context-free languages. Inform. and Comp., 73:75–86, 1987.Google Scholar
  9. [9]
    L. Stockmeyer and U. Vishkin. Simulation of parallel random access machines by circuits. SIAM J. Comput., 13(2):409–422, May 1984.Google Scholar
  10. [10]
    H. Venkateswaran. Properties that characterize LOGCFL. In Proc. of 19th STOC, pages 141–150, 1987.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • Klaus-Jörn Lange
    • 1
  • Peter Rossmanith
    • 1
  1. 1.Institut für InformatikTechnische Universität MünchenMünchen 2

Personalised recommendations