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Collapsing oracle hierarchies, census functions and logarithmically many queries

  • Uwe Schöning
  • Klaus W. Wagner
Contributed Papers Complexity
Part of the Lecture Notes in Computer Science book series (LNCS, volume 294)

Abstract

Using a uniform method based on a technique by Kadin [5], many oracle and alternation hierarchies can be shown to collapse to their level Δ2. This improves in different respects earlier such collapse results in [3], [4] and [13]. Our results on space hierarchy classes have been improved since the first version of this paper by Immerman [8] who showed a collapse to level Σ1.

Keywords

Oracle Query Logarithmic Space Oracle Machine Collapse Result Census Function 
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-Verlag Berlin Heidelberg 1988

Authors and Affiliations

  • Uwe Schöning
    • 1
  • Klaus W. Wagner
    • 2
  1. 1.Seminar für Informatik, EWH KoblenzKoblenz
  2. 2.Institut für MathematikUniversität AugsburgAugsburg

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