There are some canceloperation transitions (back to the Main Edit view from Add Contact view and Modify Contact view) that are not shown in this diagram.
图中没有显示某些取消操作转换(从添加联系人视图和修改联系人视图返回主编辑视图)。
3
In the case where participating services are not transaction-aware (e.g., stateless), then the TCS will invoke a compensating operation (i.e., "cancel").