DriveWorksXpress is the only DriveWorks product that does not have any form of a lookup table. As a result, I've seen people create very complex rules to get around this limitation. They will nest OR statements within other OR statements within OR statements... I understand why people do this. If you start to build a rule with an "OR" statement, the wizard will get you started with this:
DriveWorksXpress builds the beginning of the structure for you, complete with the comma you need...you put a comparative equation before the comma and another equation after the comma, if either equation is true, then the "OR" returns true. However sometimes you may run into logic that is more complex than simply comparing two equations, maybe you have a chart where there are several ways a statement could be true? You actually can string as many equations as you need, within the same OR statement all separated by commas...and if any of them are true, the "OR" will return true. (Think: "if the height is 16 inches, or 26 inches, or 30 inches tall then...") Here is an example:
The same is true for the AND, you can string as many comparative equations as you need together here as well...
if all of these equations are true, then the "AND" will return true. (Think: "if the height is greater than 20 inches, and we have more than two hinges, and the cover is made of steel, and the customer wants FEMA enclosures...)
Certainly you can then put the OR statements within the AND or vice versa, but in summary it is much easier to string many of the compare statements within one DriveWorksXpress function rather than thinking you are limited to comparing only two statements at a time.