Modality Using Prolog-Like Language of Higher Order Syntax

Abstract

In the last few years modalities in a logic have a new dimension. They become very usefull in the artificial
intelligence, and, what is the a special interest of this paper, in the knowledge representation. There
are many ways to represent modalities in a formal logic, but one of the most common is through the modal logic. In the last time there are some doubts about how much is the modal logic appropriate for the representation of modalities, and specially for the knowledge representation. There are two different opinions on this topic given in [6] and [9]. In this paper we shall try to represent modalities without using of a modal logic, and, what is even more important, by using a logic that is implemented as a programming language - HiLog. This representation of modalities solves some of the problems that are described in [6].