I don't understand how sets can be closed, yet disjoint?
5323
Example to show the distance between two closed sets can be 0 even if the two sets are disjoint
74860
Why is the empty set a subset of every set?
39020
Why is empty set an open set?
52629
Example 1, Sec. 22 in Munkres' TOPOLOGY, 2nd edition: How to verify that this map is closed?
22804
Interpretation of limsup-liminf of sets
28683
Sum of two closed sets in $\mathbb R$ is closed?
143457
Is product of two closed sets closed?
126897
Showing the set $A+B$ is closed.
3896
A closed set in $(A, \mathcal T_A)$ that is not closed in $(X, \mathcal T)$
36184
Countability of disjoint intervals
114990
Is the complement of countably many disjoint closed disks path connected?
157420
Question about Subrings and integraly closed
6491
Not every open set in $\mathbb{R}^n$, for $n\geq2$, is a disjoint union of countable open balls.
70959
Prove that a set $E$ is closed iff it's complement $E^{c}$ is open
25834
Proof a set cannot contain its own powerset - Russell's Paradox
87830
Relating the union of the power set of a set to the set itself
133086
When Cantor's Intersection theorem won't work with closed sets