Why is it valid to assume that there is an index set for any set s.t each index corresponds to an element?
92793
Can every set be written as a family?
52473
How do you make a square element symbol (\in), to show that an element belongs to a collection of set?
77548
Given an arbitrary infinite set $S$, how to construct an injection $\mathbb{N} \to S$ with the Axiom of Choice?
22498
In set theory, how are real numbers represented as sets?
77791
Proving an inclusion related to algebraic sets and interpreting it
153551
Is the null set a subset of every set?
123498
Is "empty set" an element of a set?
3072
If the empty set is a subset of every set, why isn't $\{\emptyset,\{a\}\}=\{\{a\}\}$?
75765
index or position in std::set
82315
is an empty set an element of {empty set}
118030
Two subgroups of the same index must be conjugate under these assumptions
146891
Why is $\{\emptyset\} \not = \emptyset$?
13661
Axiom of Regularity allows for this set be an element of itself
87830
Relating the union of the power set of a set to the set itself
68187
Is python's "set" stable?
40232
What do we mean when we say "Let $x$ be an element of the set $\mathbb{R}$"?
148399
Two sets which contain each other as elements