Hp50g : "blocking" a variable

[BruceH]

RPL resolves a variable by looking upward through the chain of directories until it finds a match. So if variable 'A' is being erased from the current directory then create it in the parent directory, still called 'A'.

Executing 'A' PURGE in the child directory will not generate an error but it also won't delete 'A' from the parent.