Y algorithm specially tackles the problem of mining of non-certain choice and parallel models; and γ + algorithm could find out structure of mandatory loop and optional loop, of jumping forward and backward, of invisible activity etc.4. γ算法特别处理了非确定选择平行模式的挖掘问题。γ+算法可以发现强、弱循环、前跳、后跳、不可见任务等模型结构。