Compactness of a subset of $\mathbb{Q}$
48162
Is the subset $[0, \sqrt2] ∩\mathbb{Q} ⊂ \mathbb{Q}$ closed, bounded, compact?
33370
Show that the one point compactification of $\mathbb{Q}$ is not Hausdorff
127173
Closed subset of compact set is compact
82824
Affine algebraic subset of $\mathbb{A}_k^4$
155168
Is the collection of finite subsets of $\mathbb{Z}$ countable?
3296
Proof That $\mathbb{R} \setminus \mathbb{Q}$ Is Not an $F_{\sigma}$ Set
51914
Show that $S$ is compact.
95993
Isn't every subset of a compact space compact?
103383
Let $\{K_i\}_{i=1}^{\infty}$ a decreasing sequence of compact and non-empty sets on $\mathbb{R}^n.$ Then $\cap_{i = 1}^{\infty} K_i \neq \emptyset.$
148994
$K \subset \mathbb{R}^n$ is compact iff it is closed and bounded
31559
If $Z\subseteq Y\subseteq X$ and $Z$ is compact in $Y$, then $Z$ is compact in $X$
39076
Contraction of compact sets
74498
Smallest dense subset of $\mathbb{R}$
66301
The cardinality of the set of countably infinite subsets of an infinite set
22464
Which of the following subsets of   $\mathbb{R}^2$ are compact
146455
Compactness of the set of all unitary matrices in $M_2(\mathbb{C})$
95294
Dense subset of $C[0,1]$ which preserves rationals