S4logiikka
S4logiikka is a modal logic system that extends propositional logic by introducing modal operators. Specifically, it deals with the concept of "possibility" and "necessity," often represented by the operators $\Diamond$ (diamond) and $\Box$ (box) respectively. In S4logiikka, these operators are interpreted in a Kripke semantics framework where possible worlds are related by an accessibility relation. The crucial addition of S4logiikka, distinguishing it from simpler modal logics like K or T, is its inclusion of two additional axioms.
The first of these axioms is the axiom of transitivity. This axiom states that if a world
The combination of these axioms gives S4logiikka its characteristic properties. It is widely used in fields