Choiceless Polynomial Time, Counting and the Cai–Fürer–Immerman Graphs
Author(s) -
Anuj Dawar,
David Richerby,
Benjamin Rossman
Publication year - 2005
Publication title -
electronic notes in theoretical computer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.242
H-Index - 60
ISSN - 1571-0661
DOI - 10.1016/j.entcs.2005.05.024
Subject(s) - rank (graph theory) , mathematics , extension (predicate logic) , time complexity , polynomial , constant (computer programming) , discrete mathematics , point (geometry) , combinatorics , computer science , programming language , geometry , mathematical analysis
We consider Choiceless Polynomial Time (C˜PT), 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 C˜PT(Card), an extension of C˜PT with counting
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