We explore a rule-based formalisation for contracts: the rules capture conditional norms, that is, they describe situations arising during the enactment of a multi-agent system, and norms that arise from these situations. However, such rules may establish conflicting norms, that is, norms which simultaneously prohibit and oblige (or prohibit and permit) agents to perform particular actions. We propose to use a mechanism to detect and resolve normative conflicts in a preemptive fashion: these mechanisms are used to analyse a contract and suggest "amendments" to the clauses of the contract. These amendments narrow down the scope of influence of norms and avoid normative conflicts. Agents propose rules and their amendments, leading to a contract in which no conflicts may arise.
Wamberto Weber Vasconcelos, Timothy J. Norman