Suppose I have a truth tree for a modal logic statement that is closed or is open but for which I cannot continue drawing worlds, does that mean that there are no other accessible worlds in that modal logic for that statement?
I assume there are no other worlds, but perhaps my view on the accessible relation is limited by my use of truth trees.
This question is related to another one I had about a particular statement in modal system K where I was not sure if I could find a counterexample given a completed, but open truth tree: What is the counterexample in modal system K for "⬜A ➡A"?
I am interested in references providing an answer so I could quote them later and get more detailed information on this question.