car、cdr
https://www.gnu.org/software/emacs/manual/html_node/eintr/car-_0026-cdr.html#car-_0026-cdr%20
car：返回列表的第一个元素：(car ‘(rose violet daisy buttercup)) => rose
cdr：返回列表的第一个元素后面的元素：(cdr ‘(rose violet daisy buttercup)) => (violet daisy buttercup)
cons
https://www.gnu.org/software/emacs/manual/html_node/eintr/cons.html#cons%20
cons：构建列表：(cons ‘pine ‘(fir oak maple)) => (pine fir oak maple)
dolist
https://www.gnu.org/software/emacs/manual/html_node/eintr/dolist.html%20
(dolist (element list) body…)：循环地将 list 的首个元素赋值到 element，并移除该首个元素