capturing unselected rows in selection grid

Question

Hi, 
 I have an interface with a selection grid in which multiple rows can be selected, these selected rows are saved into a ri of the CDT type. I have the requirement of capturing and storing all the unselected rows (the rows which were not selected) into a ri. 
 
 Any ways to do this? 
 
 TIA!!

apoorvam · Answer

Thank you for your replies. I had tried difference() earlier but there was an error because the type of both arrays were different. 
 I tried using remove() using the original array and the selected indices and was able to get the unselected rows.