An arithmetic formula of any number of arguments may be entered using the F(x1,..,xn) SQL element. This element will result in the appropriate SQL for the formula being generated after replacing the arguments ‘x1’ to ‘xn’ in the formula with the SQL for their counterparts in the Arguments folder (where n is the number of arguments).
Variable Creation > Input > Variables: SQL Elements pane - Other > F(x1,..,xn)
Columns or other expressions can be moved into the Arguments folder. The formula to generate SQL for is specified in the Properties panel. Double-click on F(x1,..,xn) or highlight it and click Properties to create or edit the desired formula.