Compounding Objects

  • 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.

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
Vol. 49 No. 2 (2020)
Section
Research Article
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