I have been studying AD for these days and I think I understand how it works, but all functions for which AD has been applied in the lectures I've studied are elementary in the mathematical sense, I mean, with a formula with elementary functions.
That's why I want to ask you an example of an aplication of AD to a function like a black box or if you can explain to me the way experts in the field use AD in real problems (using machine learning, for example).
Thank you very much.