# Multi-Agent Deontic Logic: Reasoning About Normative Multi-Agent Systems

Course website with material: http://www.pigozzi.org/ESSLLI2018/Home.html

### Logic and Computation Courses

Multi-Agent Deontic Logic: Reasoning About Normative Multi-Agent Systems,
Gabriella Pigozzi (University Paris-Dauphine, France) and Leon van der Torre (University of Luxembourg, Luxembourg)

Week 1, 14:00 – 15:30, Room 267, Floor 2 Room 292, Floor 4

The aim of the course is to present deontic logic from a formal of view, highlighting the practical challenges raised by agents, detachment, exceptions and multiagent organizations. It is therefore complementary to most presentations of deontic logic focusing on the philosophical motivations and paradoxes or giving a linguistic perspective on deontic modality. In particular, we first present STIT theory addressing the challenges of non-deterministic actions, moral luck, and procrastination. We continue with alternative norm-based deontic logics addressing the challenge of multiagent detachment, when agents cannot assume that other agents comply with their norms. Conflicts among norms are resolved using formal argumentation, and organizations are described using collective attitudes and constitutive norms. We illustrate the logics with examples from normative multiagent systems.

Plan

Please note that each lecture can be visited as a stand-alone lecture.

Monday:

• Deontic logic and normative systems, introduction and overview. History of deontic logic as a debate between classical vs. alternative semantics.
• Multiagent deontic logic. STIT theory addressing the challenges of non-deterministic actions, moral luck, and procrastination.

Tuesday:

• Detachment. Factual versus deontic detachment, detachment with anankastic conditionals.
• Multiagent detachment.

Wednesday:

• Argumentation 1. Formal argumentation theory as a framework to solve conflicts between norms / normative arguments: violations, contrary-to-duty obligations, dilemmas, conflict resolution, constitutive and regulative norms, agents arguing about norms.
• Argumentation 2. Representation results. Hierarchical normative systems and defeasible deontic logic.

Thursday:

• Norm interpretation. Argumentation as a framework to interpret norms.
• Norm revision and merging. Revision of a set of obligations: norm change and AGM contraction and revision of rules.

Friday:

• Norms, BDI agents, and games. Social delegation cycle.
• Multiagent organizations. Collective attitudes as grounds for institutions and norms, constitutive norms in artificial institutions. Wrap up and outlook.