A note on dual Dedekind finiteness
Logic
2025-09-23 v2
Abstract
A set is dually Dedekind finite if every surjection from onto is injective; otherwise, is dually Dedekind infinite. It is proved consistent with (i.e., the Zermelo--Fraenkel set theory without the axiom of choice) that there exists a family of sets such that, for all , is dually Dedekind finite whereas is dually Dedekind infinite. This resolves a question that was left open in [J. Truss, Fund. Math. 84, 187--208 (1974)].
Cite
@article{arxiv.2412.07142,
title = {A note on dual Dedekind finiteness},
author = {Ruihuan Mao and Guozhen Shen},
journal= {arXiv preprint arXiv:2412.07142},
year = {2025}
}
Comments
6 pages