unpacking a list

[Urs Liska]

Hi all,

I don't seem to find a way to "unpack" a list. I think I won't explain
the background, but basically what I need is that
    (list (list 1 2 3) 4)
becomes
    (list 1 2 3 4)

This is a mock-up of my real code:

#(define (func-a)
   (list 1 2 3))

#(define (func-b)
   (list
    (func-a)
    4))

#(display (func-b))

What I need is that the call to (func-a) doesn't evaluate to a list but
to its elements.
I have "solved" it by actually using something like
    (append (func-a) (list f4))
but I think that's not really clean. I'd prefer directly "unpacking" the
list in situ.

Any suggestions?

TIA
Urs