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Hurewicz test sets for generalized separation and reduction

Published online by Cambridge University Press:  01 September 2007

TAMÁS MÁTRAI
TAMÁS MÁTRAI*
Affiliation:
Department of Mathematics and its Applications, Central European University, Nádor u. 6. 1051, Budapest, Hungary. email: matrait@renyi.hu
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Abstract

We prove a Hurewicz-type theorem for generalized separation: we present a method which allows us to test if for a sequence of Borel sets (Ai)i > ω satisfying there is a sequence (Bi)i < ω of Π0ξ sets such that or not. We also prove an analogous result for generalized reduction. The results of the paper are motivated by a Hurewicz-type theorem of A. Louveau and J. Saint Raymond on ordinary separation of analytic sets.

Type
Research Article
Information
Mathematical Proceedings of the Cambridge Philosophical Society , Volume 143 , Issue 2 , September 2007 , pp. 407 - 417
Copyright
Copyright © Cambridge Philosophical Society 2007

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References

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