Set that has itself as an element?
20140
Example of set which contains itself
147136
Subset of a countable set is itself countable
81406
Does every set have a group structure?
130771
Sets and the principle of inclusion and exclusion
82487
Define a mathematical set
112290
Weird behavior of & function in Set
144181
Given an arbitrary set $X$, can one always find an element outside $X$?
19856
Prove that a subset of a separable set is itself separable
137563
Can a left coset be strictly contained in a right coset?
148025
Is there an operator for 'contained in set or subset or subset of subset' and so on?
4213
The set that only contains itself
137097
Does JavaScript have an implementation of a set data structure?
125077
what is the absolute value of a set?
148399
Two sets which contain each other as elements
97951
Is the void set (∅) a proper subset of every set?
87830
Relating the union of the power set of a set to the set itself
3636
Are any two uncountable sets similar to each other?