| DROP | Removes Program from Memory | 
DROP prog$[,ERR=stmtref]
  
Where: 
| prog$ | Name of the program to be unloaded from memory. String expression. | 
| stmtref | Program line number or statement label to which to transfer control. | 
Use the DROP directive to unload a program previously loaded into memory by the ADDR directive. The memory used while the program was loaded is returned to the system. PxPlus returns an Error #17: Invalid file type or contents if you use a DROP statement for a program that is not currently loaded in memory.
ADDR Load and Lock Program in Memory
drop "ARDATE"