说明：  模拟一个petri网的行为。该程序应该读入一组转换规则，以及一组状态列表，这些状态对应于网络链路层发出了一个新分组或者接受一个新分组，初始状态也是要读入的。该程序应该从初始状态开始，随机地选择那些激活的转换，并激发这些状态，检查一下看是否有“一个主机接受了2个分组而另一台主机并没有在此期间发出新的分组”这样的情形。
(simulated a petri nets behavior. The procedure should be read into one group conversion rules, and a list of the state group, These conditions correspond to link layer network issued a new group or accept a new grouping, initial state is to be read into the. The procedure should start from the initial state, randomly selecting those activated conversion, and to stimulate these states, check to see if it "one of the hosts for a two and the other host has not issued during this period of a new" the same situation.)