1.2.3.3.3 Description
                  GNP is used to retrieve the next qualified segment
         in the dependent segments of the established parent. The
         established parent in a hierarchy DB is the lowest-level segment
         returned in previous successful GU/GN call, and is
         canceled by an unsuccessful GU/GN call.
               
                  GHNP locks the returned segment for sequential
         write operation in addition to GNP.
               
Parent topic: GNP/GHNP