SET
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(2) |
| ID | ◀ 3028 ▶ |
| Object type | Methodology or model |
A collection or class of perfectly differenciable elements, which is considered as a whole.
Sets are usually represented by letters, while their relations are represented by connecting symbols.
A set can be:
- finite, if it contains a finite number of elements;
- infinite, if it contains an infinite number of elements;
- ordered, if each element occupies a well defined place:
- null, if it does not contain any element
The set of all elements taken in account is the universal set, or universe.
Any set has a complement, i.e. the set which contains all the elements not belonging to the former one.
A subset is a set included within another one.
Sets may overlap, i.e. have at least one common element. On the contrary, sets without any common elements are disjoint sets.
Operations on sets are described by G. BOOLE's binary algebra. The well known VENN diagrams are geometric representations of sets. These representations have been recently generalized by A. EDWARDS (1989).