A proof complexity conjecture and the Incompleteness theorem

Fuente: arXiv
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Main Author: Krajicek, Jan
Format: Preprint
Published: 2023
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author Krajicek, Jan
author_facet Krajicek, Jan
contents Given a sound first-order p-time theory $T$ capable of formalizing syntax of first-order logic we define a p-time function $g_T$ that stretches all inputs by one bit and we use its properties to show that $T$ must be incomplete. We leave it as an open problem whether for some $T$ the range of $g_T$ intersects all infinite NP sets (i.e. whether it is a proof complexity generator hard for all proof systems). A propositional version of the construction shows that at least one of the following three statements is true: - there is no p-optimal propositional proof system (this is equivalent to the non-existence of a time-optimal propositional proof search algorithm), - $E \not\subseteq P/poly$, - there exists function $h$ that stretches all inputs by one bit, is computable in sub-exponential time and its range $Rng(h)$ intersects all infinite NP sets.
format Preprint
id arxiv_https___arxiv_org_abs_2303_10637
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle A proof complexity conjecture and the Incompleteness theorem
Krajicek, Jan
Logic in Computer Science
Logic
03F20, 03F40, 68Q15
F.1.3; F.4.1
Given a sound first-order p-time theory $T$ capable of formalizing syntax of first-order logic we define a p-time function $g_T$ that stretches all inputs by one bit and we use its properties to show that $T$ must be incomplete. We leave it as an open problem whether for some $T$ the range of $g_T$ intersects all infinite NP sets (i.e. whether it is a proof complexity generator hard for all proof systems). A propositional version of the construction shows that at least one of the following three statements is true: - there is no p-optimal propositional proof system (this is equivalent to the non-existence of a time-optimal propositional proof search algorithm), - $E \not\subseteq P/poly$, - there exists function $h$ that stretches all inputs by one bit, is computable in sub-exponential time and its range $Rng(h)$ intersects all infinite NP sets.
title A proof complexity conjecture and the Incompleteness theorem
topic Logic in Computer Science
Logic
03F20, 03F40, 68Q15
F.1.3; F.4.1
url https://arxiv.org/abs/2303.10637