Modal Logic

https://plato.stanford.edu/entries/logic-modal/

Python

https://www.python.org/

Tree Method of Logic/Semantic Tableaux

https://en.wikipedia.org/wiki/Method_of_analytic_tableaux

Jeffrey, Richard. Formal Logic: Its Scope and Limits. 3rd ed. McGraw Hill, 1990. ISBN 0-07-032357-7

Source Code

https://github.com/btackett3/ModalConsistencyChecker