<<>> <> <> <> <> DIRECTORY PFS, PFSClass, PFSNarrow; PFSNarrowImpl: CEDAR PROGRAM EXPORTS PFSNarrow, PFS = { OpenFileObject: PUBLIC TYPE ~ PFSClass.OpenFileObject; IsOpenFile: PUBLIC PROC [ra: REF ANY] RETURNS [BOOL] ~ { RETURN [ISTYPE[ra, PFSClass.OpenFile]]}; ToOpenFile: PUBLIC PROC [ra: REF ANY] RETURNS [PFS.OpenFile] ~ { RETURN [NARROW[ra, PFSClass.OpenFile]]}; }.