Title :
Counting quantifiers, successor relations, and logarithmic space
Author :
Etessami, Kousha
Author_Institution :
Dept. of Comput. Sci., Massachusetts Univ., Amherst, MA, USA
Abstract :
We present new expressibility lower bounds for a logic with a weak form of ordering using model theoretic games. Our lower bound is on first-order logic augmented with counting quantifiers, a logical language that over structures with a total-ordering has exactly the power of the class TC0. We prove that it cannot express a property ORD in L, over structures with a successor relation. This holds even in light of the fact that the class L itself has a logical characterization as the properties expressible in first-order logic with a deterministic transitive closure operator over structures with a successor relation. The proof uses an extension of the well known Ehrenfeucht-Fraisse Games for logics with counting. We also show that ORD is actually complete for L (via quantifier free projections), and this fact is of independent interest
Keywords :
computational complexity; formal logic; game theory; theorem proving; Ehrenfeucht-Fraisse Games; counting quantifiers; deterministic transitive closure operator; expressibility lower bounds; first-order logic; logarithmic space; logical language; model theoretic games; proof; successor relation; successor relations; total-ordering structures; weak ordering; Arithmetic; Database languages; Logic; Polynomials;
Conference_Titel :
Structure in Complexity Theory Conference, 1995., Proceedings of Tenth Annual IEEE
Conference_Location :
Minneapolis, MN
Print_ISBN :
0-8186-7052-5
DOI :
10.1109/SCT.1995.514723