b = close(dictionary_name ‖ file_handler);
function closes a file, whether opened as a dictionary or via a file
statement. The function closes either a dictionary named dictionary_name
or a text file associated with file_handler
If closing a dictionary, the dictionary will be set to a none data source
and will remain set to that source until the previous file is reopened using the open
function or if a new file is associated with the dictionary using the setfile
The function returns a logical value of 1 (true) if successful and 0 (false) otherwise.