不可达数

As for a given automata,there exists three cases:for some state which did not being visited, for some state itself indeed being not reachable although it has been visited,for some state it is equivalent to other states though it can be reached to, in these three cases it is obviously redundant to construct these automata, and the only way for us is to delete,integrate and reduct these useless states in order to minimize the number of states.

对于一个给定的自动机，它的状态中有一些根本没有被访问过，有一些尽管被访问过，但是本身是不可达的，有一些状态尽管是可达的，但是在功能上却与另一些状态等价，这样的自动机在设计和应用中显然很累赘，可以将一些无用的状态删掉，将另外一些等价状态进行整合和约简，使之状态数达到极小。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。