Yifan Hu

collaborators

2 papers

math.LO2025

Amorphous sets and dual Dedekind finiteness

Yifan Hu, Ruihuan Mao, Guozhen Shen

A set $A$ is dually Dedekind finite if every surjection from $A$ onto $A$ is injective; otherwise, $A$ is dually Dedekind infinite. An amorphous set is an infinite set that cannot…

math.LO2024

The finitary partitions with $n$ non-singleton blocks of a set

Yifan Hu, Guozhen Shen

A partition is finitary if all its blocks are finite. For a cardinal $a$ and a natural number $n$ , let $fin (a)$ and $B_{n} (a)$ b…

Amorphous sets and dual Dedekind finiteness

The finitary partitions with n non-singleton blocks of a set

The finitary partitions with $n$ non-singleton blocks of a set