Show any collection of non-intersecting lemniscates in the plane is countable
127100
Countable or uncountable set 8 signs
86685
Example of a set $S$ that is countable, but the set of limit points is uncountable
67066
Proof there is a 1-1 correspondence between an uncountable set and itself minus a countable part of it
60424
Uncountable family of uncountable compact subsets of $\mathbb{R}$
128766
Show that the set of functions $\mathbb{N}\to\{0,1\}$ is not countable
116378
Nonhomeomorphic subsets of the plane
132778
All distances are rational prove the set is countable
18223
Prove that the union of two disjoint countable sets is countable
136006
Prove that any countable cartesian product of countable sets is countable
106298
Prove that some topology is not metrizable
103769
The Cartesian product of a finite number of countable sets is countable
40937
Is the set of partial order relations over $ \mathbb{N}$ countable?
7678
Show "countable complement topology" is a topology
6161
The cartesian product $\mathbb{N} \times \mathbb{N}$ is countable
88904
Help with a proof. Countable sets.
71922
Prove Uncountable set minus a countable set is uncountable
324
Show uncountable set of real numbers has a point of accumulation