Problem related to countability of sets
35692
The set of all finite subsets of the natural numbers is countable
79974
The cardinality of Lebesgue sets
132778
All distances are rational prove the set is countable
1318
What is wrong with this proof that the power set of the natural numbers is countable?
33157
Proof that an infinite subset of $\mathbb{N}$ is countable
102543
Real definition of "countable set"
2269
Proof that the real numbers are countable: Help with why this is wrong
154474
Image of countable and uncountable sets
11959
What's wrong with this argument that $[0,1]$ is countable?
81509
The cardinality of a countable union of countable sets, without the axiom of choice
63678
Let $A$ and $B$ be countable sets. Is there any function $f$ such that a certain condition holds for an uncountable number of functions $g$?
71922
Prove Uncountable set minus a countable set is uncountable
13620
$\omega_2$ is a not countable union of countable sets without AC
125411
Infinite set always has a countably infinite subset
147136
Subset of a countable set is itself countable
23442
Cardinality of the union of infinite and countable sets
36315
Is $[0,1]$ a countable disjoint union of closed sets?