Question

Is a set of circles in $\mathbb{R}^2$ such that no two circles (not discs) overlap necessarily countable or possibly uncountable?

score 489 · Answer 1 · 2026-04-15 02:37:03

489

Views

Is a set of circles in $\mathbb{R}^2$ such that no two circles (not discs) overlap necessarily countable or possibly uncountable?

Published on 15 Apr 2026 - 2:37

score 458 · Answer 2 · 2026-04-12 17:46:44

458

Views

Prove that a countably compact, first countable $T_{2}$ space is regular.

Published on 12 Apr 2026 - 17:46

score 252 · Answer 3 · 2026-04-16 17:24:14

252

Views

Show that a sequence in $X$ converges $⇔$ it has a single cluster point

Published on 16 Apr 2026 - 17:24

score 760 · Answer 4 · 2026-04-12 16:43:32

760

Views

Prob. 4, Sec. 21, in Munkres' TOPOLOGY, 2nd ed: First countability of $\mathbb{R}_l$ and of the ordered square

Published on 12 Apr 2026 - 16:43

score 53 · Answer 5 · 2026-04-15 20:20:10

53

Views

Infinite Sets (1st yr Uni) and Axioms

Published on 15 Apr 2026 - 20:20

score 360 · Answer 6 · 2026-04-10 05:00:08

360

Views

How many real function are there?

Published on 10 Apr 2026 - 5:00

score 136 · Answer 7 · 2026-04-13 21:14:10

136

Views

Each $C^*$-embedded subset $S$ of a first countable Tychonoff space $X$ is closed.

Published on 13 Apr 2026 - 21:14

score 109 · Answer 8 · 2026-04-11 20:42:06

109

Views

First-order topologies, limit-points and convergent sequences

Published on 11 Apr 2026 - 20:42

score 3.7k · Answer 9 · 2026-04-17 01:09:18

3.7k

Views

Bases having countable subfamilies which are bases in second countable space

Published on 17 Apr 2026 - 1:09

score 2.7k · Answer 10 · 2026-04-12 02:33:52

2.7k

Views

Uncountable Cartesian product of closed interval

Published on 12 Apr 2026 - 2:33

score 56 · Answer 11 · 2026-04-11 06:00:50

56

Views

Problem with extension of a continous function

Published on 11 Apr 2026 - 6:00

score 122 · Answer 12 · 2026-04-09 06:24:33

122

Views

Is a locally compact Hausdorff quotient of a locally compact $\sigma$-compact first countable Hausdorff space always first countable?

Published on 09 Apr 2026 - 6:24

score 121 · Answer 13 · 2026-04-09 18:23:12

121

Views

Is a locally compact Hausdorff quotient of a locally compact $\sigma$-compact first countable Hausdorff space always Frechet-Urysohn?

Published on 09 Apr 2026 - 18:23

score 84 · Answer 14 · 2026-04-08 17:02:33

84

Views

Is a locally compact Hausdorff quotient of a locally compact $\sigma$-compact first countable Hausdorff space first countable on a dense set?

Published on 08 Apr 2026 - 17:02

score 275 · Answer 15 · 2026-05-02 02:17:18

275

Views

Is a locally compact hereditarily Lindelof Hausdorff space first countable?

Published on 02 May 2026 - 2:17

List Question

Is a set of circles in $\mathbb{R}^2$ such that no two circles (not discs) overlap necessarily countable or possibly uncountable?

Prove that a countably compact, first countable $T_{2}$ space is regular.

Show that a sequence in $X$ converges $⇔$ it has a single cluster point

Prob. 4, Sec. 21, in Munkres' TOPOLOGY, 2nd ed: First countability of $\mathbb{R}_l$ and of the ordered square

Infinite Sets (1st yr Uni) and Axioms

How many real function are there?

Each $C^*$-embedded subset $S$ of a first countable Tychonoff space $X$ is closed.

First-order topologies, limit-points and convergent sequences

Bases having countable subfamilies which are bases in second countable space

Uncountable Cartesian product of closed interval

Problem with extension of a continous function

Is a locally compact Hausdorff quotient of a locally compact $\sigma$-compact first countable Hausdorff space always first countable?

Is a locally compact Hausdorff quotient of a locally compact $\sigma$-compact first countable Hausdorff space always Frechet-Urysohn?

Is a locally compact Hausdorff quotient of a locally compact $\sigma$-compact first countable Hausdorff space first countable on a dense set?

Is a locally compact hereditarily Lindelof Hausdorff space first countable?

Trending Questions

Popular # Hahtags

Popular Questions