#;22> (define l `())
#;23> (set! l (alist-update 'alice 1 l))
#;24> l
((alice . 1))
#;25> (alist-update! 'alice 2 l)
((alice . 2))
#;26> l
((alice . 2))
#;27> (alist-update! 'bob 3 l)
((bob . 3) (alice . 2))
#;28> l
((alice . 2))

; loading /usr/local/lib/dev-chicken/11/srfi-1.so ...
#;31> (define x `(1 2 3))
#;32> x
(1 2 3)
#;33> (reverse! x)
(3 2 1)
#;34> x
(1)