~： No change today

The updates in the past few days have been very bad. First, the physical condition is not good, the work and rest are chaotic, and I can't adjust it all the time. I feel drowsy all day and it is difficult to get into the code word.

The second is to enter a new volume. The outline has been set, but some details have not been sorted out. I always feel like something is almost done. I often get stuck with a small problem for several hours. I feel that I have also entered the codeword bottleneck. It is painful.

Let me take a day off and resume two chapter updates tomorrow. I'm extremely sorry!