Data validation in Default Logic BPC 10.1

Hi All,

Is that possible to have following scenario:

In the input template, we have 2 Key figure : QTY and Price. If the quantity is not blank then we want to validate that the PRICE must be entered.

Can we put the validation in the default logic to say to the system if (quantity is not blank and price is blank) then system will not save the data ?

Thank you in advance.