List questions from alexandroff-double-circle | MathQA

Find the centre of the circle

Published on 21 Mar 2026 - 21:01

What do open sets look like in the Alexandroff double cirlce?

Published on 22 Mar 2026 - 11:05

Is the Alexandroff double circle compact and Hausdorff?

Published on 22 Mar 2026 - 7:08

Is the Alexandroff Double Circle first-countable?

Published on 22 Mar 2026 - 4:44

Is the Alexandroff double circle separable?

Published on 22 Mar 2026 - 5:14

My proof that the Alexandroff double circle not second-countable

Published on 24 Mar 2026 - 22:01

Example of $f$, $g$ and $a$, such that $(f \circ g)'(a)$ exists, and $g'(a)$ exists, but $f'(g(a))$ does not.

Published on 22 Mar 2026 - 3:00