Questions about dfde.

[zju-fast-lab]

Questions about dfde.

[SamuraiChamploo]

I apologize for the late response.
Regarding equation (8), the article did not provide a more detailed derivation of the formula. Due to the complexity of the original problem formulation, we could only present the analytical form of equation (8). In actual solving, we utilized the symbolic computation tools in Mathematica to obtain a lengthy expression, which was then translated into the code structure shown.

Understanding this part primarily relies on grasping the underlying principles, as it is challenging to comprehend through the step-by-step process of actual calculations.