What do you mean by overlap?

Shooting the cover is a guessing game close to divination in China.

In order to improve their divination ability, ancient mathematicians often played the game of shooting the cover, which was one of the main contents of the evaluation of Tian Wen Lang in Tang Dynasty.

"Shooting" means guessing, and "covering" means covering. "Put things under the cover, so that they can be photographed, so that clouds can be photographed." That is to say, cover a thing with containers such as boxes and bowls, and then let the guesser guess what is put below by divination. The things placed are generally some handkerchiefs, feathers, pens and other daily necessities.

Shegai originated very early and was popular in the palace as early as the Han Dynasty. According to the images, numbers and theories in the Eight Diagrams of Zhouyi, it is a very difficult game to infer concrete things from countless possible things, and it is also a kind of entertainment that scholars like.

According to historical records, Dong Fangshuo guessed that the gecko was placed under the basin of Emperor Wu of Han Dynasty. Emperor Wu of Han Dynasty was very happy and gave many things. A courtier was not convinced, and Dong Fangshuo bet that if Dong Fangshuo could guess what he had put, he would be beaten with a hundred sticks. As a result, Dong Fangshuo guessed it again, and the detainees could only admit that they were punished. Dong Fangshuo can make public his budget in a short time, which shows that he is a master of Yi studies.

Superposition is a kind of information prediction, which is a prediction method integrating performance, divination and interest.