About the unification types of the modal logics determined by classes of deterministic frames

Abstract

The unification problem in a propositional logic is to determine, given a formula F, whether there exists a substitution s such that s(F) is in that logic. In that case, s is a unifier of F. When a unifiable formula has minimal complete sets of unifiers, the formula is either infinitary, finitary, or unitary, depending on the cardinality of its minimal complete sets of unifiers. In this paper, we study the unification types of some modal logics determined by classes of deterministic frames.