saves all modified documents, closes them and exits. If
any documents cannot be saved, the action is suspended and an error message
is issued and no documents are closed. Note that only named documents can be
Exit will report an error if you have any modified unnamed
Exit will not save a document if its
corresponding file has been modified since the document was loaded or last
saved, or if its read only flag is set, in which cases an error is reported
and no documents are closed.