anchor.diff:    (declare (type queue queue))
     (eql (car (queue-state queue)) :running))
   
  -(defun enqueue (task &optional (queue *current-queue*))
  +(defun enqueue (task &optional (queue (current-queue)))
     (declare (type task-designator task)
              (type queue queue))
     (with-mutex ((queue-lock queue))
  
positive.code:     (condition-broadcast (queue-cvar queue)))
    nil)
  
  (defun enqueue-all (tasks &optional (queue *current-queue*))
    (declare (type queue queue))
    (with-mutex ((queue-lock queue))
      (assert (alive-p queue))
  
negative.code:           (t
             (enqueue task queue)))))
  
  (defun push-self-all (tasks &optional (queue (current-queue)))
    (declare (type queue queue))
    (assert (alive-p queue))
    (let ((id *worker-id*))
  