Title
On the complexity of K-SAT
Abstract
The k - SAT problem is to determine if a given k -CNF has a satisfying assignment. It is a celebrated open question as to whether it requires exponential time to solve k -SAT for k ⩾3. Here exponential time means 2 δn for some δ >0. In this paper, assuming that, for k ⩾3, k -SAT requires exponential time complexity, we show that the complexity of k -SAT increases as k increases. More precisely, for k ⩾3, define s k =inf{ δ : there exists 2 δn algorithm for solving k -SAT}. Define ETH (Exponential-Time Hypothesis) for k -SAT as follows: for k ⩾3, s k >0. In this paper, we show that s k is increasing infinitely often assuming ETH for k -SAT. Let s ∞ be the limit of s k . We will in fact show that s k ⩽(1− d / k ) s ∞ for some constant d >0. We prove this result by bringing together the ideas of critical clauses and the Sparsification Lemma to reduce the satisfiability of a k -CNF to the satisfiability of a disjunction of 2 εn k ′-CNFs in fewer variables for some k ′⩾ k and arbitrarily small ε >0. We also show that such a disjunction can be computed in time 2 εn for arbitrarily small ε >0.
Year
DOI
Venue
2001
10.1006/jcss.2000.1727
J. Comput. Syst. Sci.
Keywords
Field
DocType
time complexity,satisfiability
Discrete mathematics,Combinatorics,Exponential function,Existential quantification,3SUM,Satisfiability,Exponential complexity,Mathematics,Lemma (mathematics),Exponential time hypothesis
Journal
Volume
Issue
ISSN
62
2
Journal of Computer and System Sciences
ISBN
Citations 
PageRank 
0-7695-0075-7
281
7.99
References 
Authors
14
2
Search Limit
100281
Name
Order
Citations
PageRank
Russell Impagliazzo12817.99
Ramamohan Paturi2126092.20