NP might not be as easy as detecting unique solutions
NP might not be as easy as detecting unique solutions
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NP 可能不像检测独特的解决方案那么容易
DOI:
10.1145/276698.276737
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发表时间:
1997
期刊:
影响因子:
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通讯作者:
L. Fortnow
中科院分区:
文献类型:
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作者:
R. Beigel;H. Buhrman;L. Fortnow
We construct an oracle A such that PA = PA and NPA = EXPA: This relativized world has several amazing properties: The oracle A gives the first relativized world where one can solve satisfiability on formulae with at most one assignment yet P 6= NP. The oracle A is the first where PA = UPA 6= NPA = coNPA: The construction gives a much simpler proof than that of Fenner, Fortnow and Kurtz of a relativized world where all the NP-complete sets are polynomial-time isomorphic. It is the first such computable oracle. Relative to A we have a collapse of EXPA ZPPA PA/poly. We also create a different relativized world where there exists a set L in NP that is NP-complete under reductions that make one query to L but not complete under traditional many-one reductions. This contrasts with the result of Buhrman, Spaan and Torenvliet showing that these two completeness notions for NEXP coincide. Research done at Yale and the University of Maryland. Address: Elect Eng Comp Science, 19 Memorial Dr W Ste 2, Bethlehem PA 180153084, USA. Supported in part by the National Science Foundation under grants CCR-8958528, CCR-9415410 and CCR-9700417 and by NASA under grant NAG 52895. Email: beigel@eecs.lehigh.edu. http://www.eecs.lehigh.edu/ beigel/ xAddress: CWI, Kruislaan 413, 1098SJ Amsterdam, The Netherlands. Partially supported by the Dutch foundation for scientific research (NWO) by SION project 612-34-002, and by the European Union through NeuroCOLT ESPRIT Working Group Nr. 8556, and HC&M grant nr. ERB4050PL93-0516. Email: buhrman@cwi.nl. http://www.cwi.nl/ buhrman/ {Research done while on leave at CWI. Address: University of Chicago, Department of Computer Science, 1100 E. 58th. St., Chicago, IL 60637, USA. Supported in part by NSF grant CCR 92-53582, the Dutch Foundation for Scientific Research (NWO) and a Fulbright Scholar award. Email: fortnow@cs.uchicago.edu. http://www.cs.uchicago.edu/ fortnow