@tindex pop
@defmac pop listname
This macro is a way of examining the @sc{car} of a list,
-and taking it off the list, all at once. It is new in Emacs 21.
+and taking it off the list, all at once.
It operates on the list which is stored in the symbol @var{listname}.
It removes this element from the list by setting @var{listname}
@defmac push newelt listname
This macro provides an alternative way to write
@code{(setq @var{listname} (cons @var{newelt} @var{listname}))}.
-It is new in Emacs 21.
@example
(setq l '(a b))