a data processing controlled display system for the interactive display and control of operations through a displayed tree having a plurality of items to be acted upon , wherein a parent item at one level has at least one child item at the next lower level , and means for enabling a modification of at least one property of all of the child items by enabling a designation of the modification of the property at the parent level without the modification of any property of the parent item . the system also has means for enabling the modification of the properties of at least one of the child items independently of any designation of modification made at the parent level .