Modeling Contrary-to-Duty with CP-nets
This work addresses a theoretical problem in deontic logic for researchers in formal methods and AI ethics, but it appears incremental as it applies an existing formalism (CP-nets) to a known domain without introducing a new paradigm.
The paper tackles the problem of representing deontic concepts, such as obligations and permissions, in a formal logic framework by using conditional preference nets (CP-nets) to model contrary-to-duty obligations and distinguish between strong and weak permission. It defines a restricted deontic logic and maps it into CP-nets, leveraging their computational properties for analysis.
In a ceteris-paribus semantics for deontic logic, a state of affairs where a larger set of prescriptions is respected is preferable to a state of affairs where some of them are violated. Conditional preference nets (CP-nets) are a compact formalism to express and analyse ceteris paribus preferences, which nice computational properties. This paper shows how deontic concepts can be captured through conditional preference models. A restricted deontic logic will be defined, and mapped into conditional preference nets. We shall also show how to model contrary to duties obligations in CP-nets and how to capture in this formalism the distinction between strong and weak permission.