Further Discussion of the Problem about Conditions of Neighborhoods Forming a Partition

There is an open question regarding Rough Set theory propsosed by Yun and Qiu(2011), which are how to characterize the conditions for a neighborhood of a data item approximations to form a partition of the universe U of the data by using only their upper and lower operators. The first part of the question has been solved Fan and Hu(2012). In this paper, another part of the question is addressed by a special and simple method, and some significant results are obtained.