$scm
SCM version 5e5, Copyright (C) 1990-2006 Free Software Foundation.
SCM comes with ABSOLUTELY NO WARRANTY; for details type `(terms)'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `(terms)' for details.
;loading /usr/share/slib/require
;done loading /usr/share/slib/require.scm
;loading /usr/share/slib/require
;done loading /usr/share/slib/require.scm
;loading /usr/lib/scm/Link
;done loading /usr/lib/scm/Link.scm
;loading /usr/lib/scm/Transcen
;done loading /usr/lib/scm/Transcen.scm
> (+ 1 2 3)
6
> (- ( + 3 4) (- 4 5 ))
#
> 7
> -1
>
;WARNING: "/usr/lib/scm/Iedline.scm": unexpected ")"#
> (- ( + 3 4) (- 4 5 ))
8
>
Debian 