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DESCRIPTIONS AND CARDINALS BELOW $\delta _5^1$

Published online by Cambridge University Press:  01 December 2016

STEVE JACKSON  and
FARID T. KHAFIZOV
STEVE JACKSON
Affiliation:
DEPARTMENT OF MATHEMATICS UNIVERSITY OF NORTH TEXAS DENTON, TX 76203-1430, USAE-mail: stephen.jackson@unt.edu
FARID T. KHAFIZOV
Affiliation:
DEPARTMENT OF MATHEMATICAL SCIENCES UNIVERSITY OF TEXAS AT DALLAS 800 WEST CAMPBELL ROAD RICHARDSON, TX 75080-3021, USAE-mail: farid.khafizov@gmail.com
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Abstract

Assuming AD, we show that all of the ordinals below $\delta _5^1$ represented by descriptions (c.f. [2], but also defined below) are cardinals. Using this analysis we also get a simple representation for the cardinal structure below $\delta _5^1$. As an application, we compute the cofinalitites of all cardinals below $\delta _5^1$.

Keywords

03E60cardinalsdescriptionsdeterminacyprojective ordinals
Type
Articles
Information
The Journal of Symbolic Logic , Volume 81 , Issue 4 , December 2016 , pp. 1177 - 1224
Copyright
Copyright © The Association for Symbolic Logic 2016 

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References

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