1.Compared with the existing methods that control all SMS in a Petri net, the deadlock prevention policy has at least three advantages: 1) only a smaller number of SMS need to be controlled, hence the deadlock-freeness or live Petri net model obtained has less additional places and arcs;
1)只需控制少量的SMS即所谓的基本信标 . 相应地 ,添加少量的控制库所和连接弧 ,就可得到无死锁或活的Petri网 .
