我想这个问题很简单, 但是我一直想不懂 = =
If there is a truncated data in interval [5 10],  we should included it in the risk set if it's truncated at 5, and exclude it if its truncated at 10.
如果是truncated 在5的话, 那么这个数据小于5，为什么反而要包括在内呢?  提前谢谢啦