What does the combination of Ding and Ren mean?

According to the book of life, ten days of dry two phases, A has turned to earth. Ethyl heptyl fund. Propionic acid water. Ding Renhua herded pentadecanol into fire. Because the condition of transformation is combination, only combination can transform, so transformation is also called combination. There is an article in the second volume (on ten dry combinations), saying that the so-called combination is harmony. Why is it harmonious after integration? The book says that the fire in the south is most afraid of the water from the north, and the fire in the south is Yang's brother and the fire in the south is Yin's sister, so the fire in the south wants to marry his sister to Yang's water as his wife, so it is a harmony between Yin and Yang. By extension, some people say that the five elements are compatible with water and fire, but they are not necessarily. As far as ding huo ren shui is concerned, although the five elements are fire and water, they are generally yang fire and yin water. But Ding Huo is negative, while Renshui is positive. This combination of yin and yang is incompatible.