Exactly, lets take it a step further and forbid selling (teaching) things you don't own.

If I desire to charge people to teach them what an array is I must provide the explanation of the array myself.

If the book is really to good to skip a teaching license must be acquired that names the specific chapters and their purpose. The rights holder doesn't have to sell by chapter but if anyone wants to make a more specific version at a better price they can.

Ideally work towards a single book for each year with a wiki for educators to debate changes and updates.