The $ I and $ j variables are counters that control the addition of a vertical bar ( | ) which is an OR symbol in the HTK format .

$i和$j变量是计数器，控制 垂直竖线（）的添加，这个竖线是HTK 格式中的一个OR符号。

Recently sequential pattern mining algorithms can be divided into three classes : a candidate generation-and-test approach based on Apriori a candidate generation-and-test approach based on vertical format a pattern-growth method .

目前的主要序列模式挖掘算法可以分为3类：①基于Apriori的候选码生成-测试的方法；②基于 垂直 格式的候选码生成-测试的方法；