加载中…
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)].

生成讲解博客的中文版本

生成AI智能校验的中文版本