Question

$|\alpha\times\alpha|=|\alpha|$ for infinite ordinal $\alpha$, definably

score 399 · Answer 1 · 2026-03-30 07:26:43

399

Views

$|\alpha\times\alpha|=|\alpha|$ for infinite ordinal $\alpha$, definably

Published on 30 Mar 2026 - 7:26

score 413 · Answer 2 · 2015-05-20 09:49:03

413

Views

Zorn's lemma converse? (Context: Maximal proper subgroups)

Published on 20 May 2015 - 9:49

score 358 · Answer 3 · 2015-05-24 14:12:31

358

Views

For an infinite cardinal $\kappa$, $\aleph_0 \leq 2^{2^\kappa}$

Published on 24 May 2015 - 14:12

score 96 · Answer 4 · 2015-05-25 08:35:38

96

Views

Could the Hamel basis of $\mathbb{R^Z}$ be the set $\mathbb{R^Z}-{\mathbf{\{0\}}}$?

Published on 25 May 2015 - 8:35

score 231 · Answer 5 · 2015-05-26 03:54:09

231

Views

Box topology and axiom of choice

Published on 26 May 2015 - 3:54

score 614 · Answer 6 · 2015-05-29 02:14:39

614

Views

Is there a constructive discontinuous exponential function?

Published on 29 May 2015 - 2:14

score 211 · Answer 7 · 2015-05-31 09:27:03

211

Views

Partition the set of positive real number into pairs without axiom of choice?

Published on 31 May 2015 - 9:27

score 258 · Answer 8 · 2026-03-27 07:49:44

258

Views

Undetermined game of length $\omega_1+\omega$, without choice

Published on 27 Mar 2026 - 7:49

score 136 · Answer 9 · 2026-03-25 22:26:48

136

Views

If I assign a random number $r_x \in (0,1)$ to every $x \in (0,1)$ what are the odds that one of them will be a specific number?

Published on 25 Mar 2026 - 22:26

score 138 · Answer 10 · 2015-06-06 17:48:15

138

Views

Lindenbaum-Theorem only concerning sentential logic provable in ZF?

Published on 06 Jun 2015 - 17:48

score 34 · Answer 11 · 2015-06-07 11:46:38

34

Views

undecidable statement of the form "$F$ is a choice function on $M$"

Published on 07 Jun 2015 - 11:46

score 1.8k · Answer 12 · 2015-06-07 12:52:59

1.8k

Views

Do we know that we can't define a well-ordering of the reals?

Published on 07 Jun 2015 - 12:52

score 979 · Answer 13 · 2015-06-11 14:07:23

979

Views

The non-existence of non-principal ultrafilters in ZF

Published on 11 Jun 2015 - 14:07

score 232 · Answer 14 · 2026-03-29 05:34:58

232

Views

ZF and the Existence of Finitely additive measure on $\mathcal{P}(\mathbb{R})$

Published on 29 Mar 2026 - 5:34

score 592 · Answer 15 · 2026-03-27 21:36:32

592

Views

(Non-Hopfian) groups that only have quotients that are themselves or the trivial group.

Published on 27 Mar 2026 - 21:36

List Question

$|\alpha\times\alpha|=|\alpha|$ for infinite ordinal $\alpha$, definably

Zorn's lemma converse? (Context: Maximal proper subgroups)

For an infinite cardinal $\kappa$, $\aleph_0 \leq 2^{2^\kappa}$

Could the Hamel basis of $\mathbb{R^Z}$ be the set $\mathbb{R^Z}-{\mathbf{\{0\}}}$?

Box topology and axiom of choice

Is there a constructive discontinuous exponential function?

Partition the set of positive real number into pairs without axiom of choice?

Undetermined game of length $\omega_1+\omega$, without choice

If I assign a random number $r_x \in (0,1)$ to every $x \in (0,1)$ what are the odds that one of them will be a specific number?

Lindenbaum-Theorem only concerning sentential logic provable in ZF?

undecidable statement of the form "$F$ is a choice function on $M$"

Do we know that we can't define a well-ordering of the reals?

The non-existence of non-principal ultrafilters in ZF

ZF and the Existence of Finitely additive measure on $\mathcal{P}(\mathbb{R})$

(Non-Hopfian) groups that only have quotients that are themselves or the trivial group.

Trending Questions

Popular # Hahtags

Popular Questions