I don't see how that's an answer. Explain?
Well it's not that hard to explain. For example one can imagine various ways of using formulas (from high school trigonometry) like:
cos(a+b) + cos(a-b) = 2 cos(a) cos(b)
cos(a+b) - cos(a-b) = 2 sin(a) sin(b)
Obviously that's not all there is to designing circuits to use sum and difference frequencies. One has to know about circuit design generally. But those are the sort of relations being used.
Allow me to pile on. I've been trying to flesh out the idea of "economic inductance" that he describes as a part of economic modeling. And every link to that phrase goes back to his book. Nobody's written anything in public explaining how that modeling works and how things can be predicted with it. There's plenty of stuff on macroeconomic modeling, but I've never seen anything like "economic inductance" in it.
If they're down with the flu, serrapeptase will reduce mucus so they don't get pneumonia.
I don't need such help.