On the existence of large antichains for definable quasi-orders
Logic
2018-08-29 v1
Abstract
We generalize Harrington-Marker-Shelah's Dilworth-style characterization of the existence of non-empty perfect antichains to co-analytic quasi-orders, establish the analogous theorem at the next definable cardinal, and consider generalizations beyond the first level of the projective hierarchy.
Cite
@article{arxiv.1808.09056,
title = {On the existence of large antichains for definable quasi-orders},
author = {Benjamin D. Miller and Zoltán Vidnyánszky},
journal= {arXiv preprint arXiv:1808.09056},
year = {2018}
}