Logika t.25 On modal system in the neighbourhood of the Brouwer Logic

Modal logic is often described as the logic of necessity and possibility. It is a branch of modern logic with many applications to formal philosophy. In this book we examine one of the modal systems, the so-called Brouwer logic KTB, and its certain extensions. It turns out that the logics in questions enjoy many special formal properties which are interesting for their own sake and make them interesting objects of philosophical applications and interpretations.