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THE DETERMINED PROPERTY OF BAIRE IN REVERSE MATH
We define the notion of a completely determined Borel code in reverse mathematics, and consider the principle $CD - PB$ , which states that every completely determined Borel set has the property of Baire. We show that this principle is strictly weaker than $AT{R_0}$ . Any ω -model of $CD - PB$ must...
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Published in: | The Journal of symbolic logic 2020-03, Vol.85 (1), p.166-198 |
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Main Authors: | , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that cite this one |
Online Access: | Get full text |
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Summary: | We define the notion of a completely determined Borel code in reverse mathematics, and consider the principle
$CD - PB$
, which states that every completely determined Borel set has the property of Baire. We show that this principle is strictly weaker than
$AT{R_0}$
. Any
ω
-model of
$CD - PB$
must be closed under hyperarithmetic reduction, but
$CD - PB$
is not a theory of hyperarithmetic analysis. We show that whenever
$M \subseteq {2^\omega }$
is the second-order part of an
ω
-model of
$CD - PB$
, then for every
$Z \in M$
, there is a
$G \in M$
such that
G
is
${\rm{\Delta }}_1^1$
-generic relative to
Z
. |
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ISSN: | 0022-4812 1943-5886 |
DOI: | 10.1017/jsl.2019.64 |