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Essentially unbounded chains in compact sets

Published online by Cambridge University Press:  24 October 2008

D. H. Fremlin
Affiliation:
Mathematics Department, University of Essex, Colchester C04 3SQ, England
K. Kunen
Affiliation:
Mathematics Department, Van Vleck Hall, University of Wisconsin, Madison, WI 53706, U.S.A.

Extract

We discuss the possible cofinalities of ⊆ *-chains in ℕ which are ⊆ *-unbounded in their topological closures.

1. The problem. Throughout this paper, the power set ℕ of the set ℕ of natural numbers will be given its usual compact metrizable topology corresponding to the product topology of {0,1}N. We say that a ⊆ * b if a/b is finite.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1991

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References

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