ABSTRACT
A set is an untagged algorithmically positioned collection of elements in which no two elements are equivalent. The primary methods are to add an element, to determine if an element is in the set, and to remove an element. Data structures that implement the Set ADT are designed to perform these methods in constant time. Since elements can be located in constant time, there is no need to support a tracker. In a set, the iteration order can be arbitrary. In fact, the iteration order can change across different iterations. The only requirement is that each persistent element is seen exactly once in a completed iteration.
