The systems and methods maintain {TAIL ~ varying protection levels} of related objects, such as when nodes of a data structure are protected at {HEAD ~ the same or greater protection level} as their children nodes 
The systems and methods maintain { TAIL ~ varying protection levels } of related objects , such as when nodes of a data structure are protected at { HEAD ~ the same or greater protection level } as their children nodes
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH