Operators: Group

The group operator is the pair of parentheses, Open, represented by the symbol ( , and Close, represented by the symbol ) . These must always appear in matched pairs. Parentheses affect the order in which the other logical operators are applied to the terms of the expression. Always specify parentheses when coding an expression that contains different logical operators, to ensure that the terms are combined in the way you want.

Various combinations of logical operators are permitted, subject to the following limitations:

• only one level of parenthesis nesting is allowed
• double NOT operators are not supported
• an open parenthesis preceded by a NOT operator is not allowed

As in standard logic (de Morgan’s Rules), the following expressions express logical equivalence:

A    (|B    |C)          and          |(A    B)    |(A    C)

|A    |(B    C)          and           (|A    |B)    (|A    |C)

A    ¬ A   is always "False".

For example,

IN            |A            B

               ¬C         |¬D

             |(¬E            F)

A job containing this combination of IN conditions will be selected for execution when the following statements are both "True".

• B exists and C does not exist
• A exists, or D does not exist, or (E does not exist and F exists)