Relative to a Random Oracle A, PA != NPA != co-NPA with Probability 1
Relative to a Random Oracle A, PA != NPA != co-NPA with Probability 1
复制标题
相对于随机预言 A,PA != NPA != co-NPA,概率为 1
DOI:
--
复制
发表时间:
1981
期刊:
影响因子:
--
通讯作者:
John Gill
中科院分区:
文献类型:
--
作者:
Charles H. Bennett;John Gill
Let A be a language chosen randomly by tossing a fair coin for each string x to determine whether x belongs to A. With probability 1, each of the relativized classes ${\textbf{LOGSPACE}}^A $, ${\bf P}^A $, ${\bf NP}^A $, ${\bf PP}^A $, and ${\textbf{PSPACE}}^A $ is properly contained in the next. Also, ${\bf NP}^A \ne {\text{co-}} {\bf NP}^A $ with probability 1. By contrast, with probability 1 the class ${\bf P}^A $ coincides with the class ${\bf BPP}^A $ of languages recognized by probabilistic oracle machines with error probability uniformly bounded below $\tfrac{1}{2}$. ${\bf NP}^A $ is shown, with probability 1, to contain a ${\bf P}^A $-immune set, i.e., a set having no infinite subset in ${\bf P}^A $. The relationship of ${\bf P}^A $-immunity to p-sparseness and ${\bf NP}^A $-completeness is briefly discussed: ${\bf P}^A $-immune sets in ${\bf NP}^A $ can be sparse or moderately dense, but not co-sparse. Relativization with respect to a random length-preserving permutation $\pi $, instead of a rand...