DocumentCode
2264634
Title
Commutative queries
Author
Beigel, Richard ; Chang, Richard
Author_Institution
Inst. for Adv. Comput. Studies, Maryland Univ., College Park, MD, USA
fYear
1997
fDate
17-19 Jun 1997
Firstpage
159
Lastpage
165
Abstract
We consider polynomial-time Turing machines that have access to two oracles and investigate when the order of oracle queries is significant. The oracles used here are complete languages for the Polynomial Hierarchy (PH). We prove that, for solving decision problems, the order of oracle queries does not matter. This improves upon the previous result of Hemaspaandra, Hemaspaandra and Hempel, who showed that the order of the queries does not matter if the base machine asks only one query to each oracle. On the other hand, we prove that, for computing functions, the order of oracle queries does matter unless PH collapses
Keywords
Turing machines; commutation; query processing; Polynomial Hierarchy; Turing machines; commutative queries; decision problems; oracle queries; polynomial-time; Commutation; Computer science; Concurrent computing; Delay; Educational institutions; Laboratories; NASA; Polynomials; Turing machines;
fLanguage
English
Publisher
ieee
Conference_Titel
Theory of Computing and Systems, 1997., Proceedings of the Fifth Israeli Symposium on
Conference_Location
Ramat-Gan
Print_ISBN
0-8186-8037-7
Type
conf
DOI
10.1109/ISTCS.1997.595168
Filename
595168
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