We started with forearm lever exercise. Aim at a dot to create a pivot. The distance the elbows goes down is the same as the distance the finger tip goes up (assuming the pivot is right in the middle).
The meaning is that nothing is left in the middle. Every in-coming thing must go out. This is also called neutralization.
When we eat rice, ideally, we just want the energy, and other physical things should come out of the body. However, there is always some small amount of material, e.g. mineral that remains in the body. This is what causes us to be sick and become old.
Resolving door: One side comes in, the other side goes out. The key is that the door is very solid.
In our movement, redirect the incoming force to the rear foot without moving.
To be soft, it must be solid plus.