English

Global choice is not conservative over local choice for Zermelo set theory

Logic 2024-01-09 v3

Abstract

We prove that Global Choice is not conservative over ZC and that ZF - Union does not prove existence of xyx \cup y for all xx and yy. Each proof is by constructing a pathological model inside a symmetric extension of L.L.

Keywords

Cite

@article{arxiv.2312.11902,
  title  = {Global choice is not conservative over local choice for Zermelo set theory},
  author = {Elliot Glazer},
  journal= {arXiv preprint arXiv:2312.11902},
  year   = {2024}
}

Comments

11 pages