Abstract
The above figure shows some classes from the boolean and (truth-table) bounded-query hierarchies. It is well-known that if either collapses at a given level, then all higher levels collapse to that same level. This is a standard “upward translation of equality” that has been known for over a decade. The issue of whether these hierarchies can translate equality downwards has proven vastly more challenging. In particular, with regard to the figure above, consider the following claim:
This claim, if true, says that equality translates downwards between levels of the bounded-query hierarchy and the boolean hierarchy levels that (before the fact) are immediately below them.
Until recently, it was not known whether (**) ever held, except in the trivial m = 0 case. Then Hemaspaandra et al. [15] proved that (**) holds for all m, whenever k > 2. For the case k = 2, Buhrman and Fortnow [5] then showed that (**) holds when m = 1. In this paper, we prove that for the case k = 2, (**) holds for all values of m. As Buhrman and Fortnow showed that no relativizable technique can prove “for k = 1, (**) holds for all m,” our achievement of the k = 2 case is unlikely to be strengthened to k = 1 any time in the foreseeable future. The new downward translation we obtain tightens the collapse in the polynomial hierarchy implied by a collapse in the bounded-query hierarchy of the second level of the polynomial hierarchy.
Supported in part by grant NSF-INT-9513368/DAAD-315-PRO-fo-ab. Work done in part while visiting Friedrich-Schiller-Universität Jena.
Supported in part by grants NSF-CCR-9322513 and NSF-INT-9513368/DAAD-315-PRO-fo-ab. Work done in part while visiting Friedrich-Schiller-Universität Jena.
Supported in part by grant NSF-INT-9513368/DAAD-315-PRO-fo-ab. Work done in part while visiting Le Moyne College.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
E. Allender. Limitations of the upward separation technique. Mathematical Systems Theory, 24(1):53–67, 1991.
E. Allender and C. Wilson. Downward translations of equality. Theoretical Computer Science, 75(3):335–346, 1990.
R. Beigel. Bounded queries to SAT and the boolean hierarchy. Theoretical Computer Science, 84(2):199–223, 1991.
R. Beigel, R. Chang, and M. Ogiwara. A relationship between difference hierarchies and relativized polynomial hierarchies. Mathematical Systems Theory, 26(3):293–310, 1993.
H. Buhrman and L. Fortnow. Two queries. In Proceedings of the 13th Annual IEEE Conference on Computational Complexity, pages 13–19. IEEE Computer Society Press, June 1998.
J. Cai, T. Gundermann, J. Hartmanis, L. Hemachandra, V. Sewelson, K. Wagner, and G. Wechsung. The boolean hierarchy I: Structural properties. SIAM Journal on Computing, 17(6):1232–1252, 1988.
J. Cai, T. Gundermann, J. Hartmanis, L. Hemachandra, V. Sewelson, K. Wagner, and G. Wechsung. The boolean hierarchy II: Applications. SIAM Journal on Computing, 18(1):95–111, 1989.
R. Chang and J. Kadin. The boolean hierarchy and the polynomial hierarchy: A closer connection. SIAM Journal on Computing, 25(2):340–354, 1996.
J. Hartmanis, N. Immerman, and V. Sewelson. Sparse sets in NP—P: EXPTIME versus NEXPTIME. Information and Control, 65(2/3):159–181, 1985.
F. Hausdorff. Grundzüge der Mengenlehre. Leipzig, 1914.
E. Hemaspaandra, L. Hemaspaandra, and H. Hempel. An introduction to query order. Bulletin of the EATCS, 63:93–107, 1997.
E. Hemaspaandra, L. Hemaspaandra, and H. Hempel. Translating equality downwards. Technical Report TR-657, Department of Computer Science, University of Rochester, Rochester, NY, April 1997.
E. Hemaspaandra, L. Hemaspaandra, and H. Hempel. Downward collapse from a weaker hypothesis. In Proceedings of the 6th Italian Conference on Theoretical Computer Science. World Scientific Press, November 1998. To appear.
E. Hemaspaandra, L. Hemaspaandra, and H. Hempel. What’s up with downward collapse: Using the easy-hard technique to link boolean and polynomial hierarchy collapses. SIGACT News, 29(3):10–22, 1998.
E. Hemaspaandra, L. Hemaspaandra, and H. Hempel. A downward collapse within the polynomial hierarchy. SIAM Journal on Computing, 28(2):383–393, 1999.
L. Hemaspaandra and S. Jha. Defying upward and downward separation. Information and Computation, 121(1):1–13, 1995.
J. Kadin. The polynomial time hierarchy collapses if the boolean hierarchy collapses. SIAM Journal on Computing, 17(6):1263–1282, 1988. Erratum appears in the same journal, 20 (2): 404.
J. Köbler, U. Schöning, and K. Wagner. The difference and truth-table hierarchies for NP. RAIRO Theoretical Informatics and Applications, 21:419–435, 1987.
R. Ladner, N. Lynch, and A. Selman. A comparison of polynomial time reducibilities. Theoretical Computer Science, 1(2):103–124, 1975.
A. Meyer and L. Stockmeyer. The equivalence problem for regular expressions with squaring requires exponential space. In Proceedings of the 13th IEEE Symposium on Switching and Automata Theory, pages 125–129, 1972.
R. Rao, J. Rothe, and O. Watanabe. Upward separation for FewP and related classes. Information Processing Letters, 52(4):175–180, 1994.
S. Reith and K. Wagner. On boolean lowness and boolean highness. In Proceedings of the 4th Annual International Computing and Combinatorics Conference, pages 147–156. Springer-Verlag Lecture Notes in Computer Science #1449, August 1998.
P. Rohatgi. Saving queries with randomness. Journal of Computer and System Sciences, 50(3):476–492, 1995.
V. Selivanov. Two refinements of the polynomial hierarchy. In Proceedings of the 11th Annual Symposium on Theoretical Aspects of Computer Science, pages 439–448. Springer-Verlag Lecture Notes in Computer Science #775, February 1994.
V. Selivanov. Fine hierarchies and boolean terms. Journal of Symbolic Logic, 60(1):289–317, 1995.
L. Stockmeyer. The polynomial-time hierarchy. Theoretical Computer Science, 3:1–22, 1977.
K. Wagner. Number-of-query hierarchies. Technical Report 158, Institut für Mathematik, Universität Augsburg, Augsburg, Germany, October 1987.
K. Wagner. Number-of-query hierarchies. Technical Report 4, Institut für Informatik, Universität Würzburg, Würzburg, Germany, February 1989.
K. Wagner. A note on parallel queries and the symmetric-difference hierarchy. Information Processing Letters, 66(1):13–20, 1998.
G. Wechsung. On the boolean closure of NP. In Proceedings of the 5th Conference on Fundamentals of Computation Theory, pages 485–493. Springer-Verlag Lecture Notes in Computer Science #199, 1985. (An unpublished precursor of this paper was coauthored by K. Wagner).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1999 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Hemaspaandra, E., Hemaspaandra, L.A., Hempel, H. (1999). Extending Downward Collapse from 1-versus-2 Queries to j-versus-j + 1 Queries. In: Meinel, C., Tison, S. (eds) STACS 99. STACS 1999. Lecture Notes in Computer Science, vol 1563. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-49116-3_25
Download citation
DOI: https://doi.org/10.1007/3-540-49116-3_25
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-65691-3
Online ISBN: 978-3-540-49116-3
eBook Packages: Springer Book Archive