A Formal Language for Electronic Contracts

In this paper we propose a formal language for writing electronic contracts, based on the deontic notions of obligation, permission, and prohibition. We take an ought-to-do approach, where deontic operators are applied to actions instead of state-of-affairs. We propose an extension of the µ-calculus in order to capture the intuitive meaning of the deontic notions and to express concurrent actions. We provide a translation of the contract language into the logic, the semantics of which faithfully captures the meaning of obligation, permission and prohibition. We also show how our language captures most of the intuitive desirable properties of electronic contracts, as well as how it avoids most of the classical paradoxes of deontic logic. We finally show its applicability on a contract example.