Modal logic, an extension of classical logic, investigates the modes of truth such as necessity and possibility. Its development has been closely intertwined with advances in proof theory, a field ...

This is a preview. Log in through your library . Abstract Jaśkowski's discussive logic D₂ was formulated with the help of the modal logic S5 as follows (see [7, 8]): A ∊ D₂ iff ┌ A ┐ ∊ S5, where (-) ...

This is a preview. Log in through your library . Abstract Modal logic has been applied in many different areas, as reasoning about time, knowledge and belief, necessity and possibility, to mention ...