When you're through using Scheme interactively, you need to be able to get out of it. You give a command to tell the interactive Scheme system (which is just a program) to terminate.
Most systems have a special command (starting with comma or whatever
the convention is), like
,exit. (It might also be
,bye.) There may be a Scheme procedure you can
evaluate to kill the system, by evaluating a procedure call expression
in the normal way, e.g.,
In many systems (especially under UNIX), you can use an interrupt
key sequence to kill the system, if you're at the top-level. E.g.,
at the top-level prompt,
<ctrl>-D, may do it.