8 Answered Questions

[SOLVED] How to define a bijection between $(0,1)$ and $(0,1]$?

2 Answered Questions

7 Answered Questions

[SOLVED] Show that the set of all finite subsets of $\mathbb{N}$ is countable.

4 Answered Questions

6 Answered Questions

8 Answered Questions

9 Answered Questions

[SOLVED] What Does it Really Mean to Have Different Kinds of Infinities?

7 Answered Questions

[SOLVED] Cardinality of set of real continuous functions

3 Answered Questions

[SOLVED] Cartesian Product of Two Countable Sets is Countable

3 Answered Questions

[SOLVED] Associativity of symmetric difference of sets

7 Answered Questions

[SOLVED] Empty intersection and empty union

7 Answered Questions

6 Answered Questions

[SOLVED] How does Cantor's diagonal argument work?

5 Answered Questions

[SOLVED] Proof that the irrational numbers are uncountable

4 Answered Questions

[SOLVED] The cartesian product $\mathbb{N} \times \mathbb{N}$ is countable

6 Answered Questions

[SOLVED] lim sup and lim inf of sequence of sets.

3 Answered Questions

[SOLVED] What are the differences between class, set, family, and collection?

3 Answered Questions

[SOLVED] Infinite DeMorgan laws

6 Answered Questions

4 Answered Questions

[SOLVED] Bijection between an open and a closed interval

4 Answered Questions

2 Answered Questions

[SOLVED] Bijection from $\mathbb R$ to $\mathbb {R^N}$

7 Answered Questions

[SOLVED] Exactly half of the elements of $\mathcal{P}(A)$ are odd-sized

2 Answered Questions

[SOLVED] An infinite subset of a countable set is countable

7 Answered Questions

7 Answered Questions

[SOLVED] In set theory, how are real numbers represented as sets?

10 Answered Questions

[SOLVED] Is there a bijective map from $(0,1)$ to $\mathbb{R}$?

6 Answered Questions

[SOLVED] When does the set enter set theory?