What historical stories do you know about Yuan Tiangang and Li?

I know two things. One is a pushback diagram, which is really written in the case of pushback diagram. The other is that Li Shimin wants to test their mental arithmetic ability and let them find out which horse crosses the river first (touch the river first).

0 1, the birth of pushback graph

Knowing that there were two magicians in the Tang Dynasty, one was Li and the other was Yuan Tiangang, I asked someone to invite them to count their national fortunes for the Tang Dynasty. In the seventeenth year of the Tang Dynasty, Li began to calculate the historical trend of the Tang Dynasty with Zhouyi Bagua. This kind of calculation is like drinking wine and being addicted for a while. Yuan Tiangang looked at Li sweating like a pig, patted him on the back and said: Let's stop here. It's time to have a rest. ?

Li did not continue to calculate divination, and the content of this divination is the push back map of later generations. It is said that this book is one of the rare history books, which clearly records the historical trend of China after 2000 and is very accurate.

02. Cut off the horse and cross the river

Looking at the sunny weather and the growing national strength in the Tang Dynasty, Emperor Taizong led Yuan Tiangang and Li out for a stroll. Walking slowly, I don't know how far I have gone. I see a river not far away, and there are two good horses by the river. One horse is as hot as fire, and the other is like charcoal. Li Shimin became interested and said to them. You two are so clever, you might as well calculate for me which of the two horses got to the river first. ?

Li and Yuan Tiangang are both excellent warlocks. If ordinary people ask such low-level questions, they are too lazy to pay attention, but the person who asks the questions is a brother of the Tang Dynasty. If you don't answer truthfully, you may be beheaded. So Yuan Tiangang pinched his finger and said, Divination is for fire, and a horse with fire color should touch the river first. ? Li smiled knowingly and said? Brother Li is really smart, but the fire needs wood to light, so the dark horse must get wet first. ?

The two people disagreed, and the scene was a bit embarrassing. Li Shimin is very happy, which is exactly what he wants to see. Soon, two horses approached the river, and finally the dark horse touched the water first and crossed the river first. You look a little ugly, Li explained. Without Brother Plough, I don't think it would be the horse who touched the river first. ? The three men looked at each other and laughed.