(defun syncer-create-test-repo (repo-symbol initial-elements)
  "Create a test repository under REPO-SYMBOL with INITIAL-ELEMENTS."
  (set repo-symbol
        (list
         (cons 'get-all
                (lambda () (get repo-symbol 'elements)))
         (cons 'put-element
                (lambda (el) (put
                 repo-symbol
                 'elements
                 (append (get repo-symbol 'elements) (list el)))))
         (cons 'get-element
                (lambda (id) (car (remove-if
                  (lambda (el)
                    (not (eq id (cdr (assoc 'ID el)))))
                  (get repo-symbol 'elements)))))
         (cons 'delete-element
               (lambda (id)
                (put
                 repo-symbol
                 'elements
                 (remove-if
                  (lambda (el)
                    (eq id (cdr (assoc 'ID el))))
                  (get repo-symbol 'elements)))))
         ))
)

(syncer-create-test-repo 'repo-a '( ((ID A)) ((ID B)) ((ID C))) )
(syncer-create-test-repo 'repo-b '( ((ID D)) ((ID E)) ((ID F))) )
(syncer-create-test-repo 'repo-status '( ((ID D)) ((ID F)) ))

(funcall (cdr(assoc 'get-all repo-a)))