anchor.diff:  
     ;; Remove the most recent piece
     (setf (group-pieces group)
  -        (delete pos (group-pieces group)))
  +        (remove pos (group-pieces group)))
   
     ;; Unless there are no more pieces in the group
     (if (< 0 (length (group-pieces group)))
  
positive.code: (defun pg (d1 d2)
    (play-game (init-game) d1 d2 t))
  
  
  (defun copy-vector (in-vec)
    (let ((out-vec (make-array (length in-vec)))
          )
  
negative.code:     
      ;; Remove the groups from the opponent's groups
      (setf (svref (gg-groups game) opponent) 
            (remove group (svref (gg-groups game) opponent)))
  
      ;; Add them to player's captures
      (push group (svref (gg-captures game) player))
  