Usually after ten years of transportation, then: 1, heavenly stems are the surface, earthly branches are the interior, heavenly stems are the appearance, and earthy branches are the essence. From now on, the earthly branch is the dominant force; 2. In the first five years, the sky is stronger, and in the second five years, the ground is stronger; 3. We should also consider the relationship between heavenly stems and earthly branches and other countries, such as birth penalty to break through the damage. Jia Mu was Jin Shenke, and Mu Yi was You Jinke, so the power of gold is stronger. If it is Jiazi, Yihai, the ground branch is aquatic and the wood is stronger.
In short, if we look at the eight characters dialectically and changefully, the "Yi" in Zhouyi itself has the meaning of change.