Problem with proving that sets can't contain themselves
62208
If $A$ is a non-empty set, then $A \notin A$
158671
Cardinality of a set that consists of all existing cardinalities
81203
Supremum and infimum of sets
129227
An example of neither open nor closed set
64075
Prove that a set of connectives is inadequate
22804
Interpretation of limsup-liminf of sets
74440
How does the axiom of regularity forbid self containing sets?
85225
The set of integers is not open or is open
158882
Prove the existence of some weird family of sets
10839
Problem in Cardinality and Order
158569
Proving a particular subset of $R^n$ is closed
147136
Subset of a countable set is itself countable
7112
Product of sets and supremum
148399
Two sets which contain each other as elements
144787
Show that the set of all infinite subsets of $\mathbb{N}$ has cardinality greater than $\mathbb{N}$
71922
Prove Uncountable set minus a countable set is uncountable
6291
Proving something is a linearly independent subset