What is the meaning of Fu Yi in the eight characters? There is another relative word, what's it called? Does anyone know?

Any two columns in the eight characters are exactly the same, which is called Yin Fu; Any two pillars in the eight characters are called anti-tune. For example, there are two identical pillars among the four pillars, which are called Yin Fu; For example, two of the four pillars, Jiazi and Wu Geng, completely collide with each other, which is called anti-tune.