Combinatorial aspects of F$_\sigma$ filters with an application to $\mathcal N$-sets
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- by Claude Laflamme
- Proc. Amer. Math. Soc. 125 (1997), 3019-3025
- DOI: https://doi.org/10.1090/S0002-9939-97-03926-9
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Abstract:
We discuss F$_\sigma$ filters and show that the minimum size of a filter base generating an undiagonalizable filter included in some F$_\sigma$ filter is the better known bounded evasion number ${\frak e}_{ubd}$. An application to $\mathcal {N}$-sets from trigonometric series is given by showing that if $A$ is an $\mathcal {N}$-set and $B$ has size less than ${\frak e}_{ubd}$, then $A \cup B$ is again an $\mathcal {N}$-set.References
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Bibliographic Information
- Claude Laflamme
- Affiliation: Department of Mathematics and Statistics, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Email: laflamme@acs.ucalgary.ca
- Received by editor(s): September 18, 1995
- Received by editor(s) in revised form: May 1, 1996
- Additional Notes: This research was partially supported by NSERC of Canada.
- Communicated by: Andreas R. Blass
- © Copyright 1997 American Mathematical Society
- Journal: Proc. Amer. Math. Soc. 125 (1997), 3019-3025
- MSC (1991): Primary 04A20; Secondary 03E05, 03E15, 03E35
- DOI: https://doi.org/10.1090/S0002-9939-97-03926-9
- MathSciNet review: 1401747