There is not a set of all sets?
13374
Why is "the set of all sets" a paradox, in Layman's terms?
86263
How do we show there are the same number of elements in each of the sets?
102592
Arbitrary Set A a Function??
4213
The set that only contains itself
111723
Can it be proven in $\sf ZF^{\neg\infty}$ that the sets $x_n=\{x_{n+1}\}$ do not exist?
27025
How do I choose an element from a non-empty set?
99480
Why is predicate "all" as in all(SET) true if the SET is empty?
124325
Element of, subset of and empty sets
49147
Showing that the class of all sets of a particular cardinality is not a set.
77171
How to find unique multisets of n naturals of a given domain and their numbers?
50258
How can a set contain itself?
36721
Is "The empty set is a subset of any set" a convention?
14512
Why cannot a set be its own element?
158882
Prove the existence of some weird family of sets
126633
Is a contradiction enough to prove a set equality to $\varnothing$?
5313
Existence of how many sets is asserted by the axiom of choice in this case?
144181
Given an arbitrary set $X$, can one always find an element outside $X$?