The design and implementation of XSIEQ are presented. XSIEQ uses a modified pushdown automata technique,and its idea is to convert all XPath expressions into a single NFA,then to attach type label and corresponding index info on NFA state.

• XSIEQ采用修改了的下推自动机技术,对多个XPath式按前缀共享的方式构造NFA,并对NFA状态进行类型标记和添加索引;