Compounding Objects

Authors

  • Zvonimir Šikić University of Zagreb

DOI:

https://doi.org/10.18778/0138-0680.2020.10

Keywords:

Łoś's theorem, converse of Łoś's theorem, filter, proper filter, ultrafilter

Abstract

We prove a characterization theorem for filters, proper filters and ultrafilters which is a kind of converse of Łoś's theorem. It is more natural than the usual intuition of these terms as large sets of coordinates, which is actually unconvincing in the case of ultrafilters. As a bonus, we get a very simple proof of Łoś's theorem.

References

[1] J. M. Łoś, Quelques Remarques, Théorèmes Et Problèmes Sur Les Classes Définissables D'algèbres, Studies in Logic and the Foundations of Mathematics, vol. 16 (1955), Mathematical Interpretation of Formal Systems, pp. 98–113.
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Published

2020-06-30

How to Cite

Šikić, Z. (2020). Compounding Objects. Bulletin of the Section of Logic, 49(2), 181–184. https://doi.org/10.18778/0138-0680.2020.10

Issue

Section

Research Article