There is no such word as "cardinary" so it is not possible to answer the questions.
Chat with our AI personalities
the set of every set is that set
null set or empty set, is a set with no elements.
The set contained in another set is termed as a sub-set.
A null set is a set that does not contain any elements, an empty set.
A null set is a set with nothing in it. A set containing a null set is still containing a "null set". Therefore it is right to say that the null set is not the same as a set containing only the null set.