eq-assoc++.lisp

(defun eq-assoc (assoc-a assoc-b)
  (and (equal (length assoc-a) (length assoc-b))
       (reduce (lambda (accum pair)
                 (and accum
                      (equal pair (assoc (car pair) assoc-b))))
               assoc-a
               :initial-value t)))

(defun group (list)
  (let ((even t))
    (remove nil (maplist (lambda (l)
                           (if (not (setf even (not even)))
                               (cons (car l) (cadr l))))
                         list))))

(defun your-test (list-a list-b)
  (eq-assoc (group list-a) (group list-b)))

(defun test ()
  (let ((one '(a b c d))
        (two '(c d a b))
        (three '(a c b d)))
    (and (your-test one one) (your-test two two)
         (your-test one two) (your-test two one)
         (not (your-test one three)) (not (your-test three one))
         (not (your-test two three)) (not (your-test two three)))))