English

Very basic set theory

History and Overview 2026-01-29 v8 Logic

Abstract

Ernst Zermelo's axiomatization of set theory (1908) did not exclude `a set that is a member of itself'. We call a set that is a member of itself `an individual'. In this article we prove the elimination of Russell's paradox is equivalent to "For every set S, an individual is a member of S or a set (but not an individual) is not a member of S". This shows there is place in set theory for individuals. And we show the set theory with individuals has its philosophical foundation in Ludwig Wittgenstein's Tractatus Logico-Philosophicus.

Cite

@article{arxiv.2303.13473,
  title  = {Very basic set theory},
  author = {Doeko Homan},
  journal= {arXiv preprint arXiv:2303.13473},
  year   = {2026}
}

Comments

8 pages

R2 v1 2026-06-28T09:30:34.109Z