The element <booleanFunction> is a Boolean function that returns the value "true" or "false" against a single expression in the Process DM. The Boolean function evaluates the element <expression> based on the attribute "booleanAction" with the following definitions– "not" – Returns the inverse Boolean value of the expression operand.• "defined" – Returns "true" if the variable is in the state table and is not asserted to "noValue" value.