Once having learned how to start you must learn how to stop, just like the apprentice sorcerer. You can stop the programming environment by giving the quit-command
where upon you are asked for a confirmation
The possible answers (as elicited by the help-command) are <#21#>y<#21#> and <#22#>n<#22#>. Upon answering
the quit-command does nothing and the confirmation message disappears from your screen. Upon answering
the programming environment halts and returns control to the system on which it is running. Upon quitting, the program that is then in memory is forgotten (but of course all programs that have been written to a file are retained).