Existence of the set of all subsets of a set
52614
(exercise from Tao's analysis book) Proof of a lemma relating to power set of X
11817
Proving that every set $A \subset \Bbb N$ of size $n$ contains a subset $B \subset A$ with $n | \sum_{b \in B} b$
19856
Prove that a subset of a separable set is itself separable
30968
Is it possible that every set can be specified?
158882
Prove the existence of some weird family of sets
32441
How to prove or disprove statements about sets
130156
Image of the union and intersection of sets.
19414
Uncountable subset with uncountable complement, without the Axiom of Choice
81406
Does every set have a group structure?
23225
Union of connected subsets is connected if intersection is nonempty
126015
Elementary number theory in sets
76405
Let n be an even integer. How many different ways can I choose subsets of the set {1,2...,n}
3392
Sum of products of elements of nonempty subsets of A set
92249
Every finite set contains its supremum: proof improvement.
2403
Can a countable set contain uncountably many infinite subsets such that the intersection of any two such distinct subsets is finite?
113668
Uncountable chain of subsets of $\mathbb N$
59813
Prove that for all sets A and B, A ∩ B = ∅ implies ( A ∪ B ) - B = A