A Note on the Model Theory for Positive Modal Logic
Sergio Arturo Celani, Ramón Jansana · Fundamenta Informaticae · 2012
The minimum system of Positive Modal Logic SK+ is the (∧, ∨, □, ◊, ⊥, $\top$)-fragment of the minimum normal modal logic K with local consequence. In this paper we develop some of the model theory for SK+ along the yet standard lines of the model the