Ok, so let's be more precise. What I expect an accessible work to do is to explain things using terms that are as simple as possible. This does not mean to exp

Ok, so let's be more precise. What I expect an accessible work to do is to explain things using terms that are as simple as possible. This does not mean to explain it like the reader was a child but, most of all, to avoid one simple pitfall: Imagine you learn A, then learn B (which builds on A), and finally learn C (which builds on A and B). Now you have the knowledge to explain A more correctly and elegantly in terms of C, and you do so. However, your beautiful and correct definition of A depends on C, which depends on B, which depends on A. So your reader has to understand C in order to grasp A and A in order to grasp C. This pitfall has nothing to do with necessary complexity -- not avoiding it is simply bad didactics.