Zhengyin, which is a term in numerology speculation, is the information about the six relatives that occurs in the five elements. The six relatives marked by the heavenly stems and their relationship between them are all based on the sun stem. The sun pillar in the four pillars of the horoscope interacts with the heavenly stems hidden in the other heavenly stems and earthly branches in the four pillars, resulting in the relationship between life and restraint, such as Zhengyin, partial seal, Positive wealth, partial wealth...etc. What you call the Zhengyin of the Heavenly Stem and the Earthly Branches is this: If among your four pillars, the day pillar is the Bingwu day and the year pillar is the Yimao year, then when Yimu sees Binghuo, it is the Zhengyin, and when Earthly Branches Mao hides Yimu, it also means Binghuo. Zhengyin, in the five elements, wood generates fire, and the one who gives birth to me is the Zhengyinyin. Here we only talk about the correct seal. It is very complicated to talk about the partial seal.