def exists_in_default_path(sheet):
 default_path_sheet = os.path.join(sheets.default_path(), sheet)
 return ((sheet in sheets.get()) and os.access(default_path_sheet, os.R_OK))

def exists_in_default_path ( sheet ) : default_path_sheet = os . path . join ( sheets . default_path ( ) , sheet ) return ( ( sheet in sheets . get ( ) ) and os . access ( default_path_sheet , os . R_OK ) )
predicate that returns true if the sheet exists in default_path .