Spahn algebraic- and coalgebraic semantics of modal logic (Rev #2, changes)

1 Introduction

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An important difference of the coalgebraic approach compared to the algebraic one is that coalgebras generalize rather than dualize the model theory of modal logic. One may generalize the concept of modal logic from Kripke frames to arbitrary coalgebras. In fact the link between modal logic and coalgebra is so strong that one may claim that modal logic is the natural logic for coalgebras (just like equational logic is that for algebra)

9 Coalgebras: an introduction

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