Universal set.
"Universe" and "universal set" are two unrelated concepts.
A universal set is a set that contains all the elements under consideration for a particular discussion or problem. It is used in set theory to define the range of possibilities within a given context.
If the universal set contains N elements then it has 2N subsets.
Yes. A null set is always a subset of any set. Also, any set is a subset of the [relevant] universal set.
The universal set is the set containing each and every element under consideration.
It is the set of "everything".
If the universal set, U, has N elements then it has 2N subsets.
The complement of an empty set is universal set
The null set. It is a subset of every set.
null set ,universal set,cardinality set
The universal subset is the empty set. It is a subset of all sets.