Modeling Deontic Modal Logic in the s(CASP) Goal-directed Predicate Answer Set Programming System

TL;DR

This paper presents a novel approach to implementing deontic modal logic within answer set programming, resolving longstanding paradoxes and enabling modeling of conditional obligations.

Contribution

It introduces a direct encoding of deontic modal operators using ASP's negation features and employs global constraints to represent normative concepts.

Findings

Successfully resolves classic deontic paradoxes

Enables modeling of conditional obligations and prohibitions

Provides an elegant ASP-based framework for deontic logic

Abstract

We consider the problem of implementing deontic modal logic. We show how (deontic) modal operators can be elegantly and directly expressed using default negation (negation-as-failure) and strong negation present in answer set programming (ASP). We propose using global constraints of ASP to represent obligations, prohibitions, and permissions in deontic modal logic. We show that our proposed representation results in the various decades-old paradoxes of deontic modal logic being simply and elegantly resolved. Our method also serves as a means for modeling conditional obligations and conditional prohibitions in knowledge representation.