Plaster

(defun add-element (element) (let ((member-p (check-member element))) (if member-p (progn (remhash (gethash member-p *id-hash-table*) *value-hash-table*) (setf (gethash member-p *id-hash-table*) (remf element :id)) (setf (gethash element *value-hash-table*) member-p)) (progn (setf (gethash (incf *id-counter*) *id-hash-table*) element) (setf (gethash element *value-hash-table*) *id-counter*) element))))