A stack in common lisp.

stack.lisp

(defparameter *stack* 
  (list 0))

(defun push-to-stack (&rest args)
  "This pushes any number of arguments to the stack."
  (dolist (arg args)
    (push arg *stack*)
    (print "ok")))

(defun pop-stack (&rest args)
  "This remove any number of pieces from the stack."
  (dolist (arg args)
    (defparameter *stack*
      (remove arg *stack*))))
  
(defun clear-stack ()
  (defparameter *stack*
    (list 0)))

(defun stack ()
  (print *stack*))

(defun add-stack-data ()
  (apply #'+ (mapcar #'+ *stack*)))
 
(pop-stack 10)
(push-to-stack (* 10 10))
(push-to-stack 10)
(push-to-stack "TEXT")
(stack)
(clear-stack)
(add-stack-data)