Is the empty set a member of itself
30660
Empty set does not belong to empty set
118824
What is the complement of empty set?
58285
Is it true that if $X$ is connected, then for every nonempty proper subset $A$ of $X$, we have $\mathbf{Bd} \ne \emptyset$
65768
What is the cardinality of the set of the empty set?
4213
The set that only contains itself
155233
$A=\emptyset $ if and only if $B = A \bigtriangleup B$
146891
Why is $\{\emptyset\} \not = \emptyset$?
46317
What is an Empty set?
44160
Set theory: difference between belong/contained and includes/subset?
3072
If the empty set is a subset of every set, why isn't $\{\emptyset,\{a\}\}=\{\{a\}\}$?
5230
Why can a 1 element set be a member of another set but not a subset of it?
132692
Nonempty set mapped to $\emptyset$ and vice-versa
143003
$\bigcup \emptyset$ is defined but $\bigcap \emptyset$ is not. Why?
14512
Why cannot a set be its own element?
121847
Don't we need the axiom of choice to choose from a non-empty set?
660
Is the empty space really empty?
34099
Proving that the empty set is unique