Formal Logic 2

This is the second part of the course on formal logic. Whereas formal logic 1 focused on propositional and predicate logic, this part focuses on modal logic and its cognates. Modal logic is the logic of necessity and possibility. That is, modal logic investigates the logical behavior of statements such as “it must be the case that p”, “it is necessary that p”, “it is possible that p”, “it is contingent that p”, and so on and so forth.

The course covers several classical modal systems, and it will feature proof construction and the analogous of refutation trees. Moreover, the course also covers modal systems of temporal logic, deontic logic, and epistemic logic. Modal logic takes into account not only how things actually are, but also how they could be. To do so, modal logic uses a formal semantics featuring modal operators and an underlying structure composed of possible worlds. The resulting formal language enriches the language of propositional and predicate logic.