Marked_++Marked_--zyx+(-(x,y),z)-(+(x,z),y)-(+(x,y),y)x+(-(x,y),z)-(+(x,z),y)-(+(x,y),y)xMarked_+(-(x,y),z)Marked_-(+(x,z),y)Marked_+(-(x,y),z)Marked_+(x,z)+(-(x,y),z)-(+(x,z),y)-(+(x,y),y)xMarked_+(-(x,y),z)Marked_+(x,z)Marked_+1Marked_+(-(x,y),z)Marked_+(x,z)+(-(x,y),z)-(+(x,z),y)-(+(x,y),y)x