Syllabus
Necessity and possibility, modal formulas. Kripke semantics (relational semantics).
Characteristic class of a logic. Traditional propositional modal logics: K, K4, T, S4, S5, GL.
Their characteristic classes. P-morphisms, bisimulations and non-characterizable classes of frames.
Completeness, decidability, finite model property. Intuitionistic propositional logic.