ArticleOriginal scientific text

Title

Cofinal Σ1_1 and Π1_1 subsets of ωω

Authors ,

Abstract

We study properties of 1_1 and π1_1 subsets of ωω that are cofinal relative to the orders ≤ (≤*) of full (eventual) domination. We apply these results to prove that the topological statement "Any compact covering mapping from a Borel space onto a Polish space is inductively perfect" is equivalent to the statement "αωω,ωωL(α) is bounded for ≤*".

Bibliography

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Pages:
161-193
Main language of publication
English
Received
1998-05-20
Published
1999
Exact and natural sciences