Rights, Duties and Commitments between Agents

In this paper we introduce a multi agent de-ontic update semantics, that builds on a logic of prescriptive obligations (norms) and a logic of descriptive obligations (normative propositions). In this preference-based logic we formalize rights as a new type of strong prescriptive permissions and duties and commitments as prescriptive obligations between agents. 1 Introduction In groups of agents there is a fundamental difference between an agent creating an obligation or permission for another agent and an agent evaluating whether such de-ontic states hold, because the former is an act whereas the latter is an assessment. For example, a purchase contract creates an obligation for the buyer to pay the seller for the goods, when buying a CD via the Inter-net the buyer can grant permission to the merchant to charge his credit card by sending his card number, and the city counsel can grant a permission to a person to build a house. Usually deontic states are created by performing certain actions like the actual signing of a contract , instructions by a superior, and pressing an 'agree' button on a website. 1 These creations of deontic states are quite different from the evaluation of deontic states where one agent assesses the deontic states of another agent (or himself) to determine which obligations, permissions and rights actually hold. For example, a seller might want to know whether he or the buyer is responsible for paying import taxes for the goods that he shipped to the buyer, and an Internet consumer might want to know whether he has to pay if someone makes fraudulent use of the credit card number he gave to an Internet merchant. Clearly, the most difficult reasoning task concerns the interaction between creation and evaluation of deontic states. Signing a sales contract is easy, but deriving all the legal implications of the contract is a task for legal experts. such an active action is typical for contractual obligations , but it is of course not always required. Certain rights, e.g. human rights, always apply and do not have to be created for every person individually. In advanced applications of multi-agent systems the agents must be able to reason about the creation as well as the evaluation of deontic states, because in electronic communication the agents should be able to reason whether they commit themselves or create any liability by the messages they exchange. Lack of this reasoning …