+(defun rassoc (x alist &key (test #'eql))
+ (while alist
+ (if (funcall test x (cdar alist))
+ (return)
+ (setq alist (cdr alist))))
+ (car alist))
+
+(defun acons (key datum alist)
+ (cons (cons key datum) alist))
+
+(defun pairlis (keys data &optional (alist ()))
+ (while keys
+ (setq alist (acons (car keys) (car data) alist))
+ (setq keys (cdr keys))
+ (setq data (cdr data)))
+ alist)
+
+(defun copy-alist (alist)
+ (let ((new-alist ()))
+ (while alist
+ (push (cons (caar alist) (cdar alist)) new-alist)
+ (setq alist (cdr alist)))
+ (reverse new-alist)))