English

A proof complexity conjecture and the Incompleteness theorem

Logic in Computer Science 2026-02-16 v2 Logic

Abstract

Given a sound first-order p-time theory TT capable of formalizing syntax of first-order logic we define a p-time function gTg_T that stretches all inputs by one bit and we use its properties to show that TT must be incomplete. We leave it as an open problem whether for some TT the range of gTg_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⊈P/polyE \not\subseteq P/poly, - there exists function hh that stretches all inputs by one bit, is computable in sub-exponential time and its range Rng(h)Rng(h) intersects all infinite NP sets.

Keywords

Cite

@article{arxiv.2303.10637,
  title  = {A proof complexity conjecture and the Incompleteness theorem},
  author = {Jan Krajicek},
  journal= {arXiv preprint arXiv:2303.10637},
  year   = {2026}
}

Comments

preliminary version March 2023, revised September 2023

R2 v1 2026-06-28T09:22:50.886Z