Positive Modal Logic is the restriction of the modal local consequence relation defined by the class of all Kripke models to the propositional negation-free modal language. The class of positive modal algebras is the one canonically associated with PML according to the theory of the algebraization of logics. In , a Priestley-style duality is established between the category of positive modal algebras and the category of K+-spaces. In this paper, we establish a categorical equivalence between the category K+of K+-spaces and the category Coalg(V) of coalgebras of a suitable endofunctor V on the category of Priestley spaces. ©2003 Published by Elsevier Science B. V.
Palmigiano, A. (2003). Coalgebraic semantics for positive modal logic. In Electronic Notes in Theoretical Computer Science (Vol. 82, pp. 227–242). https://doi.org/10.1016/S1571-0661(04)80641-8