RobotML : {0}." Ports should be correctly typed. "RobotML: {0}." Ports should be correctly connected. "RobotML: {0}." The name of the element shoud be alphanumeric. "RobotML : {0}." Connection should be set between ports that are not already connecty. "RobotML : {0}." Problem of recursivity: A subsystem (Property) should not be typed by the same system that contains it. "RobotML : {0}." Problem of recursivity: A subsystem (Property) should not be typed by the same system that contains it. "RobotML : {0}." Connection must be set between ports that are not already connected.