On infinite sets with no $3$ on a line
Combinatorics
2026-02-26 v1
Abstract
We give a construction of an infinite set of points in such that any subset has a constant density subset with no three points collinear and yet cannot be separated into finitely many subsets such that each subset has no three points collinear. This provides a new proof of a question of Erd\H{o}s, Ne\v{s}et\v{r}il, and R\"{o}dl. The construction was generated by an internal model at OpenAI.
Keywords
Cite
@article{arxiv.2602.21275,
title = {On infinite sets with no $3$ on a line},
author = {Moe Putterman and Mehtaab Sawhney and Gregory Valiant},
journal= {arXiv preprint arXiv:2602.21275},
year = {2026}
}
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2 pages