NOT logical operator

The NOT logical operator reverses the true/false outcome of the expression that immediately follows.

• The NOT operator affects only the expression that immediately follows, unless a more complex logical expression is enclosed in parentheses.
• You can substitute ~ or ¬ for NOT as a logical operator.
• NOT can be used to check whether a numeric variable has the value 0, 1, or any other value. For example, all scratch variables are initialized to 0. Therefore, NOT (#ID) returns false or missing when #ID has been assigned a value other than 0.