Choiceless Polynomial Time, Counting and the Cai-Fürer-Immerman Graphs: (Extended Abstract)
Choiceless Polynomial Time, Counting and the Cai-Fürer-Immerman Graphs: (Extended Abstract)
复制标题
无选择多项式时间、计数和 Cai-Fürer-Immerman 图:(扩展摘要)
DOI:
10.1016/j.apal.2007.11.011
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发表时间:
2008
期刊:
影响因子:
--
通讯作者:
Benjamin Rossman
中科院分区:
文献类型:
--
作者:
A. Dawar;David Richerby;Benjamin Rossman
We consider Choiceless Polynomial Time (C̃PT), a language introduced by Blass, Gurevich and Shelah, and show that it can express a query originally constructed by Cai, Fürer and Immerman to separate fixed-point logic with counting (IFP + C) from P. This settles a question posed by Blass et al. The program we present uses sets of unbounded finite rank: we demonstrate that this is necessary by showing that the query cannot be computed by any program that has a constant bound on the rank of sets used, even in C̃PT(Card), an extension of C̃PT with counting.