anchor.diff:                (push nlocation unclaimed-neighbors))))))
       (when unclaimed-neighbors
         (claim-parts unclaimed-neighbors grid))
  -    (setf (current-unclaimed grid) (count cell-unclaimed (cells grid)))))
  +    (let ((new-unclaimed (count cell-unclaimed (cells grid))))
  +      (prog1 (- (current-unclaimed grid) new-unclaimed)
  +        (setf (current-unclaimed grid) new-unclaimed)))))
   
   (defun claim-parts (possibilities grid)
     (with-weight-computation (:delay grid)
  
positive.code:          (setf (movement-actions player) '()))
          (t (outer-world))))
  
  
  ;;;; Enemy
  
negative.code:            (when (= (incf (death-tick enemy)) enemy-death-ticks)
               (remove-object enemy)))
            ((= cell-claimed (cell-ref location (grid enemy)))
             (enemy-die enemy))
            ((need-new-target-p location enemy)
             (setf (target-location enemy) (choose-target-cell location enemy)))))
    (when (null (death-tick enemy))
  