A wood is an element representing growth, and B wood is a representative of formation. In other words, Wood A represents the physics of hair growth, and Wood B represents the substance of formation. The same is true of C and D. C stands for the element of fire and D stands for the fire formed.
Moreover, there are yin and yang in the middle, for example, Jiamu is yang wood, Yibu is yin wood, C is yang fire, Ding is yin fire, Geng is yang gold, Xin is yin gold, Ren is yang water, decyl is yin water, E is yang soil and E is yin soil.
Extended data
Heavenly dryness is one of the symbols of ancient timing. Used to record years and days, representing ten years or ten days. In order, the stems are: A, B, C, D, E, F, G, Xin, N, D ... where A, C, E, G and N are singular and belong to Yang; B, D, Ji, Xin and Gui are even numbers and belong to Yin.
Ten days' work is related to combination. These conflicts are: A-E, B-E, C-G, D-Xin, E-N, G-A, Xin-B, N-C and D-D. Mixing: A-B mixed soil, B-G mixed gold and C-N mixed water. Ding and ren combine wood, and they combine fire.
Baidu Encyclopedia-heavenly stems and earthly branches