わけがわからないので、展開してみたが余計わけがわからなくなった件

Programing Gauche p53のcopy-listという手続き

(define (copy-list lis)
  (if (pair? lis)
      (cons (car lis) (copy-list (cdr lis)))
      lis))

(copy-list '(aa bb cc))

(cons (car '(aa bb cc)) (copy-list (cdr '(aa bb cc))))

(cons 'aa (copy-list (cdr '(aa bb cc))))

(cons 'aa (copy-list '(bb cc)))

(cons 'aa (cons (car '(bb cc)) (copy-list (cdr '(bb cc)))))

(cons 'aa (cons 'bb (copy-list '(cc))))

(cons 'aa (cons 'bb (cons (car'(cc)) (copy-list (cdr '(cc))))))

(cons 'aa (cons 'bb (cons 'cc (copy-list ()))))

(cons 'aa (cons 'bb (cons 'cc ())))

(cons 'aa (cons'bb'(cc)))

(cons 'aa'(bb cc))

'(aa bb cc)

Programing Gauche p54のappend2という手続き

(define (append2 a b)
  (if (pair? a)
      (cons (car a) (append2 (cdr a) b))
      b))

(append2 '(aa bb) '(cc))

(cons (car '(aa bb)) (append2 (cdr '(aa bb)) '(cc)))

(cons 'aa (append2 '(bb) '(cc)))

(cons 'aa (append2 '(bb) '(cc)))

(cons 'aa (cons (car '(bb)) (append2 (cdr '(bb)) '(cc))))

(cons 'aa (cons 'bb (append2 () '(cc))))

(cons 'aa (cons 'bb (append2 () '(cc))))

(cons 'aa (cons 'bb '(cc)))

(cons 'aa '(bb cc))

'(aa bb cc)