English

$\mathsf{RT}_2^2$ does not imply $\mathsf{WKL}_0$

Logic 2016-02-12 v1

Abstract

We prove that RCA0+RT22↛WKL0\mathsf{RCA}_0+\mathsf{RT}_2^2\not\rightarrow \mathsf{WKL}_0 by showing that for any set CC not of PA-degree and any set AA, there exists an infinite subset GG of AA or Aˉ\bar{A}, such that GCG\oplus C is also not of PA-degree.

Cite

@article{arxiv.1602.03784,
  title  = {$\mathsf{RT}_2^2$ does not imply $\mathsf{WKL}_0$},
  author = {Lu Liu},
  journal= {arXiv preprint arXiv:1602.03784},
  year   = {2016}
}

Comments

12 pages

R2 v1 2026-06-22T12:48:28.303Z