User Dominic van der Zypen

6 votes

2 answers

406 views

Existence of a "diagonal" set in certain set systems

asked Jul 17, 2017 at 13:28

6 votes

1 answer

787 views

Primes that are "almost" multiples of each other

asked Jul 21, 2017 at 4:15

6 votes

1 answer

1k views

Proof of Fisher's inequality in combinatorial terms

asked Apr 6, 2017 at 9:23

6 votes

2 answers

385 views

Irreducible elements in endomorphism rings

asked Mar 8, 2017 at 7:58

6 votes

1 answer

271 views

Non-isomorphic projective planes on $\omega$

asked Feb 5, 2017 at 15:25

6 votes

2 answers

241 views

Existence of a path in a set of subsets of $\omega$

asked Feb 20, 2017 at 7:30

6 votes

1 answer

193 views

Uniquely complemented but not Boolean

asked Oct 9, 2016 at 12:10

6 votes

1 answer

140 views

Maximality and non-Hausdorffness

asked Nov 18, 2016 at 9:03

6 votes

3 answers

884 views

Lower density of {primes} times themselves

asked Jun 3, 2015 at 8:30

6 votes

1 answer

1k views

Countable group with uncountable number of subgroups $< 2^{\aleph_0}$ [duplicate]

asked Jun 17, 2015 at 14:22

6 votes

1 answer

269 views

Graph of graph homomorphisms

asked May 1, 2015 at 10:39

6 votes

2 answers

453 views

Minimum number of unit fractions to sum up a given positive rational

asked Jan 2, 2015 at 14:41

6 votes

1 answer

559 views

Sierpinski-like spaces

asked Jan 6, 2015 at 15:12

6 votes

1 answer

119 views

Universality with respect to quotients

asked Oct 23, 2014 at 12:08

6 votes

1 answer

492 views

Decidability of Frankl's union-closed sets conjecture

asked Dec 5, 2014 at 14:51

6 votes

2 answers

180 views

Isomorphic Hadwiger graphs

asked Nov 24, 2014 at 9:59

6 votes

2 answers

237 views

Realizing a monoid as $\mathrm{End}(G)$ for some graph $G$

asked Nov 27, 2014 at 8:25

6 votes

1 answer

258 views

Does "$|{\cal P}_2(X)| = |X|$ for $X$ infinite" imply ${\sf (AC)}$?

asked Jan 12, 2016 at 8:06

6 votes

0 answers

141 views

Doubly edge-contraction critical graphs

asked Aug 17, 2016 at 19:33

6 votes

2 answers

782 views

Generalizing Ramanujan's "1729 story"

asked Apr 26, 2016 at 15:01

6 votes

1 answer

223 views

Minimal Hausdorff topologies compatible with a bunch of functions

asked Nov 18, 2015 at 10:55

6 votes

1 answer

2k views

Quotients of posets

asked Oct 1, 2015 at 11:25

6 votes

3 answers

2k views

Countable path-connected Hausdorff space

asked Aug 11, 2015 at 13:58

5 votes

2 answers

982 views

Fermat's Last Theorem "$\pm k$"

asked Aug 10, 2015 at 7:18

5 votes

1 answer

312 views

Does "$\forall Z(C(X,Z) \cong C(Y,Z))$" imply $X\cong Y$?

asked Jul 8, 2015 at 7:25

5 votes

1 answer

198 views

Closeness graph of a topological space

asked Oct 6, 2015 at 6:45

5 votes

2 answers

468 views

Approximating integers with prime quotients [closed]

asked Sep 22, 2015 at 7:20

5 votes

0 answers

70 views

Does the $D$-property have universal objects?

asked Sep 3, 2015 at 8:36

5 votes

1 answer

337 views

Hadwiger-Nelson problem for $\ell^\infty$

asked Jul 30, 2016 at 12:09

5 votes

2 answers

830 views

"Common-neighbor-regular" graphs

asked Mar 24, 2016 at 8:05

Stack Exchange Network

1,209 Questions

Existence of a "diagonal" set in certain set systems

Primes that are "almost" multiples of each other

Proof of Fisher's inequality in combinatorial terms

Irreducible elements in endomorphism rings

Non-isomorphic projective planes on $\omega$

Existence of a path in a set of subsets of $\omega$

Uniquely complemented but not Boolean

Maximality and non-Hausdorffness

Lower density of {primes} times themselves

Countable group with uncountable number of subgroups $< 2^{\aleph_0}$ [duplicate]

Graph of graph homomorphisms

Minimum number of unit fractions to sum up a given positive rational

Sierpinski-like spaces

Universality with respect to quotients

Decidability of Frankl's union-closed sets conjecture

Isomorphic Hadwiger graphs

Realizing a monoid as $\mathrm{End}(G)$ for some graph $G$

Does "$|{\cal P}_2(X)| = |X|$ for $X$ infinite" imply ${\sf (AC)}$?

Doubly edge-contraction critical graphs

Generalizing Ramanujan's "1729 story"

Minimal Hausdorff topologies compatible with a bunch of functions

Quotients of posets

Countable path-connected Hausdorff space

Fermat's Last Theorem "$\pm k$"

Does "$\forall Z(C(X,Z) \cong C(Y,Z))$" imply $X\cong Y$?

Closeness graph of a topological space

Approximating integers with prime quotients [closed]

Does the $D$-property have universal objects?

Hadwiger-Nelson problem for $\ell^\infty$

"Common-neighbor-regular" graphs