Empty set representation
125502
Empty set literal?
31376
If null set is an element of a set then will it belongs to set or subset?
152354
Why is an empty set not a terminal object in categories $\mathsf{Top}$ and $\mathsf{Sets}$?
150857
Equivalence relations on S given no relation?
17784
Java if ternary operator and Collections.emptyList()
89712
For every set $A$, the empty set is a subset of $A$. The empty set is a set. Therefore, the empty set has a cardinality $\geq 1\ldots$
110677
How is an empty set truly "empty"?
1307
Infimum and supremum of the empty set
36721
Is "The empty set is a subset of any set" a convention?
112883
How to initialize a dict with keys from a list and empty value in Python?
132692
Nonempty set mapped to $\emptyset$ and vice-versa
27107
intersection of the empty set and vacuous truth
81351
Polish space in which the interior of each compact set is empty
110485
Nested sequence of non-empty compact subsets - intersection differs from empty set
143003
$\bigcup \emptyset$ is defined but $\bigcap \emptyset$ is not. Why?
114378
How to check if the string is empty?
3072
If the empty set is a subset of every set, why isn't $\{\emptyset,\{a\}\}=\{\{a\}\}$?