English

Consistency of circuit evaluation, extended resolution and total NP search problems

Logic 2016-06-28 v1 Logic in Computer Science

Abstract

We consider sets Γ(n,s,k)\Gamma(n,s,k) of narrow clauses expressing that no definition of a size ss circuit with nn inputs is refutable in resolution R in kk steps. We show that every CNF shortly refutable in Extended R, ER, can be easily reduced to an instance of Γ(0,s,k)\Gamma(0,s,k) (with s,ks,k depending on the size of the ER-refutation) and, in particular, that Γ(0,s,k)\Gamma(0,s,k) when interpreted as a relativized NP search problem is complete among all such problems provably total in bounded arithmetic theory V11V^1_1. We use the ideas of implicit proofs to define from Γ(0,s,k)\Gamma(0,s,k) a non-relativized NP search problem iΓi\Gamma and we show that it is complete among all such problems provably total in bounded arithmetic theory V21V^1_2. The reductions are definable in S21S^1_2. We indicate how similar results can be proved for some other propositional proof systems and bounded arithmetic theories and how the construction can be used to define specific random unsatisfiable formulas, and we formulate two open problems about them.

Keywords

Cite

@article{arxiv.1509.03048,
  title  = {Consistency of circuit evaluation, extended resolution and total NP search problems},
  author = {Jan Krajicek},
  journal= {arXiv preprint arXiv:1509.03048},
  year   = {2016}
}

Comments

Preliminary version 10.September 2015