The veins are such that negative force of light energy functions through them.

There is a physical explanation for its energy function.

However, the trend has been towards using more physically based potential energy functions.

Several free energy functions may be formulated based on system criteria.

The energy function should be flexible enough without causing overfitting.

Around 1969, there was considerable interest in developing potential energy functions for small molecules.

A conservative force is one that has a potential energy function.

In these cases, the terms in potential energy function will be changed but the number of variables remains constant.

Would you believe nothing but mechanical energy functions here?

This may be a potential energy function for some physical problem.