Almost disjoint refinement of families of subsets of

Authors:
Bohuslav Balcar and Peter Vojtáš

Journal:
Proc. Amer. Math. Soc. **79** (1980), 465-470

MSC:
Primary 04A20; Secondary 54A25, 54D40

DOI:
https://doi.org/10.1090/S0002-9939-1980-0567994-2

MathSciNet review:
567994

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Abstract | References | Similar Articles | Additional Information

Abstract: Without any set-theoretic assumptions, we prove that every uniform ultrafilter on the set *N* of all natural numbers has a Comfort system, that is, an almost disjoint refinement. Moreover, we describe one type of ideal such that the family of all subsets of *N* that are not contained in it has an almost disjoint refinement.

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Additional Information

DOI:
https://doi.org/10.1090/S0002-9939-1980-0567994-2

Keywords:
Ultrafilter,
almost disjoint family,
-point,
refinement

Article copyright:
© Copyright 1980
American Mathematical Society