Computable Ramsey's Theorem for Pairs Needs Infinitely Many Pi-0-2 Sets
Logic
2015-07-14 v1
Abstract
In \cite{J}, Theorem 4.2, Jockusch proves that for any computable k-coloring of pairs of integers, there is an infinite homogeneous set. The proof uses a countable collection of sets as potential infinite homogeneous sets. In a remark preceding the proof, Jockusch states without proof that it can be shown that there is no computable way to prove this result with a finite number of sets. We provide a proof of this latter fact.
Keywords
Cite
@article{arxiv.1507.03256,
title = {Computable Ramsey's Theorem for Pairs Needs Infinitely Many Pi-0-2 Sets},
author = {Gregory Igusa and Henry Towsner},
journal= {arXiv preprint arXiv:1507.03256},
year = {2015}
}