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):

  1. Negations
  2. Intersections
  3. 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.