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YCor
YCor
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Non-Analytically Measurable Setanalytically measurable set in $\Delta^1_2$

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John Levy
John Levy
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I'm wondering if there is some reference you may know that gives an explicit set which is not analytically-measurable (i.e., not in the sigma-algebra generated by $\Sigma^1_1$), notbut which is not in $\Delta^1_2$? I can prove that such a set exists but just wondering if there's a (fairly) concrete example.

I'm wondering if there is some reference you may know that gives an explicit set which is analytically-measurable (i.e., in the sigma-algebra generated by $\Sigma^1_1$), not which is not in $\Delta^1_2$? I can prove that such a set exists but just wondering if there's a (fairly) concrete example.

I'm wondering if there is some reference you may know that gives an explicit set which is not analytically-measurable (i.e., not in the sigma-algebra generated by $\Sigma^1_1$), but which is in $\Delta^1_2$? I can prove that such a set exists but just wondering if there's a (fairly) concrete example.

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John Levy
John Levy
  • 119
  • 3

Non-Analytically Measurable Set in $\Delta^1_2$

I'm wondering if there is some reference you may know that gives an explicit set which is analytically-measurable (i.e., in the sigma-algebra generated by $\Sigma^1_1$), not which is not in $\Delta^1_2$? I can prove that such a set exists but just wondering if there's a (fairly) concrete example.