it depends on where you are trying to write it...Michael's solution is the simplest. but you may also want to look into set analysis. or provide context...example of a set analysis expression where you are calculating sum of Sales for all entities with "type" = m6 is something like:
not knowing your requirement or having a sample file, the above expressions are supposed to be examples...you will have to modify them to your specific requirement. if you are expecting an answer that works off the bat, you may want to attach a sample qvw or elaborate your requirements with some details.
