To exit from the editor by suspending the current editor session, type:
^x ^z
The system displays the message
Stopped
at the bottom of the screen and returns you to the
command prompt. However, the Emacs/Prolog job is only suspended
(that is, in the background) and you can resume it at any time. To
resume your Emacs/Prolog session, type fg (for "foreground")
at the command prompt.