In this article , we study zhang zhan ' s annotation on lei - tzu , and proceed to distinguish and analysis his " wu " and " shiu " 另一方面则藉由对虚字的剖析，详述张湛以虚为轴心，融合佛、道思想及两汉元气论，建立独树一帜的宇宙观。
2.
Virtual fields , such as fields referencing basic subroutines , cannot be updated using sql , as the database cannot reverse engineer the retrieval process 虚字段，例如引用basic子程序的字段，是不能使用sql来更新的，因为数据库不能执行检索过程的反向工程。
