NOT

NOT function is used to invert the Boolean value of an expression. It is useful for explicitly testing for a false condition.

COMMAND SYNTAX

    NOT(expression)

SYNTAX ELEMENTS

expression may evaluate to any Boolean result.

NOTES

The NOT function will return Boolean TRUE if the expression returns a Boolean FALSE. It will return Boolean FALSE if the expression returns a Boolean TRUE.

The NOT function is useful for explicitly testing for the false condition of some test and can clarify the logic of such a test.

EXAMPLE

    EQU Sunday TO NOT( MOD( DATE(), 7))
    IF Sunday THEN
       CRT "It is Sunday!"
    END

In this example, the expression MOD (DATE(),7) will return 0 (FALSE) if the day is Sunday and 1 to 6 (TRUE) for the other days. To explicitly test for the day Sunday we need to invert the result of the expression. By using the NOT function we return 1 (TRUE) if the day is Sunday and 0 (FALSE) for all other values of the expression.