Abstract

This volume concerns the achievements of Janusz Czelakowski in the broadly defined field of algebraic logic. However, instead of the algebraic logic, we decided to use the term of logical consequence operation in the title of the volume. There are several reasons for this. Firstly, the logical consequence operation is a trademark of the Polish School of Logic, while Janusz Czelakowski is undoubtedly a prominent representative of this School. Secondly, the notion of consequence operation is a kind of bridge between algebra and logic, semantics and syntax. It allows properties of logical systems to be put into words in terms of properties of classes of algebras and vice versa. Thirdly, and perhaps most importantly, it is precisely this sort of research that constitutes the mainstream of Janusz Czelakowski achievements.