Title
A Switching Lemma for Small Restrictions and Lower Bounds for k - DNF Resolution
Abstract
We prove a new switching lemma that works for restrictions that set only a small fraction of the variables and is applicable to DNFs with small conjunctions. We use this to prove lower bounds for the Res(k) propositional proof system, an extension of resolution which works with k -DNFs instead of clauses. We also obtain an exponential separation between depth d circuits of bottom fan-in k and depth d circuits of bottom fan-in k +1. Our results for Res(k) are:1. The 2n to n weak pigeonhole principle requires exponential size to refute in Res(k), for k \leqslant \sqrt {{{\log n} \mathord{\left/ {\vphantom {{\log n} {\log \log n}}} \right. \kern-\nulldelimiterspace} {\log \log n}}}.2. For each constant k, there exists a constant wk so that random w -CNFs require exponential size to refute in Res(k).3. For each constant k , there are sets of clauses which have polynomial size Res(k+1) refutations, but which require exponential size Res(k) refutations.
Year
DOI
Venue
2002
10.1137/S0097539703428555
SIAM Journal on Computing
Keywords
Field
DocType
exponential size,bottom fan-in k,small fraction,small conjunction,exponential separation,polynomial size res,log n,exponential size res,small restrictions,switching lemma,dnf resolution,constant k,lower bounds,constant wk,boolean circuits,resolution,lower bound
Discrete mathematics,Binary logarithm,Combinatorics,Exponential function,Polynomial,Upper and lower bounds,Propositional proof system,Disjunctive normal form,Mathematics,Lemma (mathematics),Pigeonhole principle
Conference
Volume
Issue
ISSN
33
5
0097-5397
Citations 
PageRank 
References 
42
1.34
23
Authors
3
Name
Order
Citations
PageRank
Nathan Segerlind122311.22
Samuel R. Buss295684.19
Russell Impagliazzo35444482.13