The following operations on sets can be performed with operators: union, difference, symmetric difference, inclusion and intersection. Elements can be added or removed from the set with the Include or Exclude operators. The operators needed for this are listed in table (12.6).
Operator | Action |
+ | Union |
- | Difference |
* | Intersection |
>< | Symmetric difference |
<= | Contains |
>= | Left hand side set is a superset of the one on the right |
include | include an element in the set |
exclude | exclude an element from the set |
in | check whether an element is in a set |
The set type of the operands must be the same, or an error will be generated by the compiler.
The following program gives some valid examples of set operations:
As can be seen, the union is equivalent to a binary OR, while the intersection is equivalent to a binary AND, and the symmetric difference equals a XOR operation.
The Include and Exclude operations are equivalent to a union or a difference with a set of one element. Thus,
is equivalent to
and
is equivalent to
The In operation results in a True if the left operand (an element) is included of the right operand (a set), the result will be False otherwise.