User 喻 良

37 votes

Accepted

Can one cover the plane with less than continuum of lines?

answered Oct 22, 2013 at 7:09

17 votes

When will the real numbers be Borel?

answered Jun 10, 2018 at 15:50

12 votes

Accepted

Non null Turing antichain

answered Sep 22, 2015 at 1:43

11 votes

Partitioning $\mathbb{R}$ into $\aleph_1$ Borel sets

answered Nov 14, 2011 at 1:59

9 votes

Accepted

Borel Sets in Sacks Generic Extension

answered Jul 20, 2014 at 10:44

9 votes

Is there a perfect set of ground model reals in the Cohen extension?

answered Oct 13, 2016 at 2:13

9 votes

Is it known how the Sigma Algebra generated by Jordan measurable sets compares to universally measurable sets and analytic sets?

answered Nov 20, 2018 at 0:36

8 votes

Accepted

Sets computable from enough hints

answered Sep 29, 2014 at 0:57

8 votes

A "suitably generic" set of Cohen reals without forcing?

answered Jun 4, 2014 at 13:13

8 votes

Accepted

Martin's cone theorem and recursion theory

answered Apr 13, 2011 at 9:07

6 votes

A G-delta-sigma that is not F-sigma?

answered May 22, 2011 at 8:41

6 votes

Accepted

Martin-Löf randomness relative to a $\Delta^0_2$-representation of a real

answered Jun 18, 2014 at 8:58

6 votes

Borel cross section

answered Mar 10, 2015 at 17:59

5 votes

Accepted

Analytic uniformization

answered Aug 7, 2013 at 11:06

5 votes

Vitali Sets vs Bernstein Sets...

answered May 20, 2012 at 2:14

5 votes

A compactness property for Borel sets

answered May 7, 2011 at 3:51

5 votes

Accepted

Is checking whether a compact $\Pi^0_1$-class is nonempty $\Sigma^1_1$-hard?

answered Nov 12, 2019 at 3:23

5 votes

Connection between countable ordinals and Turing degrees

answered Nov 18, 2017 at 1:16

5 votes

Accepted

Double Posner-Robinson Join (or a cupping analog of minimal pair)

answered Apr 29, 2023 at 1:18

5 votes

Steinhaus theorem and Hausdorff dimension

answered Sep 1, 2023 at 5:43

4 votes

Accepted

$\Pi^0_2$ singleton forming minimal pair with $0''$

answered May 21, 2023 at 13:42

4 votes

Is there a Borel subset of $ \mathbb{R}^{2} $, with finite vertical cross-sections, whose projection onto the first component is non-Borel?

answered Nov 19, 2016 at 4:21

4 votes

To find an element of a $\Pi^1_1$ set

answered Jul 22, 2012 at 1:59

4 votes

Definition of HYP in $L_{\omega_1^{CK}}[a]$?

answered Jan 12, 2013 at 14:38

4 votes

Accepted

Degree of unsolvability of finding a open approximation to a Borel set, given its Borel code

answered Apr 4, 2015 at 18:43

3 votes

Accepted

Are lightface \Delta-1-1 classes of reals describable with hyperarthmetic formulae?

answered Jul 23, 2014 at 11:16

3 votes

Probability that a Turing machine will nontrivially reduce a real

answered Apr 29, 2012 at 3:51

3 votes

$\Delta^{1}_{2}$ and degrees of constructibility $\textbf{on sets}$

answered Oct 30, 2018 at 1:22

3 votes

Accepted

Does every cuppable r.e. set cup with a low set?

answered Nov 12, 2021 at 1:59

3 votes

Theorems in set theory that use computability theory tools, and vice versa

answered Apr 27, 2023 at 12:05

Stack Exchange Network

43 Answers

Can one cover the plane with less than continuum of lines?

When will the real numbers be Borel?

Non null Turing antichain

Partitioning $\mathbb{R}$ into $\aleph_1$ Borel sets

Borel Sets in Sacks Generic Extension

Is there a perfect set of ground model reals in the Cohen extension?

Is it known how the Sigma Algebra generated by Jordan measurable sets compares to universally measurable sets and analytic sets?

Sets computable from enough hints

A "suitably generic" set of Cohen reals without forcing?

Martin's cone theorem and recursion theory

A G-delta-sigma that is not F-sigma?

Martin-Löf randomness relative to a $\Delta^0_2$-representation of a real

Borel cross section

Analytic uniformization

Vitali Sets vs Bernstein Sets...

A compactness property for Borel sets

Is checking whether a compact $\Pi^0_1$-class is nonempty $\Sigma^1_1$-hard?

Connection between countable ordinals and Turing degrees

Double Posner-Robinson Join (or a cupping analog of minimal pair)

Steinhaus theorem and Hausdorff dimension

$\Pi^0_2$ singleton forming minimal pair with $0''$

Is there a Borel subset of $ \mathbb{R}^{2} $, with finite vertical cross-sections, whose projection onto the first component is non-Borel?

To find an element of a $\Pi^1_1$ set

Definition of HYP in $L_{\omega_1^{CK}}[a]$?

Degree of unsolvability of finding a open approximation to a Borel set, given its Borel code

Are lightface \Delta-1-1 classes of reals describable with hyperarthmetic formulae?

Probability that a Turing machine will nontrivially reduce a real

$\Delta^{1}_{2}$ and degrees of constructibility $\textbf{on sets}$

Does every cuppable r.e. set cup with a low set?

Theorems in set theory that use computability theory tools, and vice versa