An unboundedness property for norms of length $\geq \omega _ 2$
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- by Steve Jackson PDF
- Proc. Amer. Math. Soc. 109 (1990), 487-491 Request permission
Abstract:
We prove from the axiom of determinacy that for every norm $\varphi$ from a set of reals $A$ onto ${\omega _2}$ there is a $\Sigma _1^1$ subset of $A$ coding uncountably many ordinals. This extends a result of Kechris.References
- Steve Jackson and Donald A. Martin, Pointclasses and well-ordered unions, Cabal seminar 79–81, Lecture Notes in Math., vol. 1019, Springer, Berlin, 1983, pp. 56–66. MR 730586, DOI 10.1007/BFb0071693 A. S. Kechris, Nonexistence of norms with a strong boundedness property, (to appear).
- Yiannis N. Moschovakis, Descriptive set theory, Studies in Logic and the Foundations of Mathematics, vol. 100, North-Holland Publishing Co., Amsterdam-New York, 1980. MR 561709
Additional Information
- © Copyright 1990 American Mathematical Society
- Journal: Proc. Amer. Math. Soc. 109 (1990), 487-491
- MSC: Primary 03E15; Secondary 03E60
- DOI: https://doi.org/10.1090/S0002-9939-1990-0955997-1
- MathSciNet review: 955997