Abstract | ||
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In Descriptive Complexity, we investigate the use of logics to characterize computational complexity classes. Since 1974, when Fagin proved that the class NP is captured by existential second-order logic, considered the first result in this area, other relations between logics and complexity classes have been established. Well-known results usually involve first-order logic and its extensions, and complexity classes in polynomial time or space. Some examples are that the first-order logic extended by the least fixed-point operator captures the class P and the second-order logic extended by the transitive closure operator captures the class PSPACE. In this paper, we will analyze the combined use of higher-order logics of order i, HO^i, for i=2, extended by the least fixed-point operator, and we will prove that each level of this hierarchy captures each level of the deterministic exponential time hierarchy. As a corollary, we will prove that the hierarchy of HO^i(LFP), for i=2, does not collapse, that is, HO^i(LFP)@?HO^i^+^1(LFP). |
Year | DOI | Venue |
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2011 | 10.1016/j.entcs.2011.03.006 | Electr. Notes Theor. Comput. Sci. |
Keywords | Field | DocType |
fixed-point operator,second-order logic,higher-order logics,class pspace,deterministic exponential time hierarchy,complexity class,computational complexity class,class np,existential second-order logic,higher-order logic,class p,first-order logic,descriptive complexity,transitive closure,first order logic,polynomial time,fixed point,second order,higher order logic,computational complexity | Quantum complexity theory,Complexity class,PH,Discrete mathematics,Structural complexity theory,EXPTIME,Computer science,P,Descriptive complexity theory,Transitive closure | Journal |
Volume | ISSN | Citations |
269, | Electronic Notes in Theoretical Computer Science | 0 |
PageRank | References | Authors |
0.34 | 8 | 2 |
Name | Order | Citations | PageRank |
---|---|---|---|
Cibele Matos Freire | 1 | 1 | 1.36 |
Ana Teresa Martins | 2 | 2 | 4.80 |