You will be given a definition of a task first, then some input of the task.
In this task you will be given a passage and a yes/no question based on the passage. You should answer the question using the information from the passage.

passage: In mathematics, and more specifically set theory, the empty set or null set is the unique set having no elements; its size or cardinality (count of elements in a set) is zero. Some axiomatic set theories ensure that the empty set exists by including an axiom of empty set; in other theories, its existence can be deduced. Many possible properties of sets are vacuously true for the empty set.
 question: is an empty set an element of an empty set?
Output:
Yes