Defining Expression elements
Expression elements allow you to combine other network elements with logical operators to represent complex sets of IP addresses.
Figure: Expression element properties
- 1
- Click Add Element to select an element to use in the Expression.
- 2
- Logical operators
- 3
- Undo and redo actions
- 4
- The Expression
Logical Operators in Expressions are resolved in the following order (however, items inside parentheses are evaluated before any items outside parentheses are considered):
- Negations
- Intersections
- Unions
Expression Properties dialog box
Use this dialog box to create expressions. Expression elements combine other network elements (IP addresses) with logical operands.
| Option | Definition |
|---|---|
| Name | The name of the element. |
| Comment (Optional) |
A comment for your own reference. |
| Category (Optional) |
Includes the element in predefined categories. Click Select to select a category. |
| Option | Definition |
|---|---|
| Expression Composer | |
| Add Element | Select this option to select the elements to use in the Expression. |
 Union
|
Includes all IP addresses defined in both elements that the union combines. |
 Intersection
|
Includes only those IP addresses that the two elements that the intersection combines have in common. |
 Negation
|
Includes all IP addresses except those that are defined in the element that follows the negation. |
 Open
Parenthesis
|
Parentheses group parts of the expression together. Items inside parenthesis are evaluated before they are compared to items outside the parenthesis. |
 Close
Parenthesis
|
Parentheses group parts of the expression together. Items inside parenthesis are evaluated before they are compared to items outside the parenthesis. |
 Undo
|
Click to undo the last action you did. |
 Redo |
Click to redo the last action you did. |