Formalizing uncertainty in service request/offer description and matching

This paper discusses the problem of describing and matching service requests and offers, that appears as central and characteristic in the context of the Service Oriented Computing (SOC) paradigm. Service descriptions, be they requests or offers, are seen as a mix of detailed, local state information, and fuzzy information, or speculation, about remote partners. Service fruition is represented, at a very high abstraction level, as an atomic interaction among two or more parties, each providing a partial view about a global state change. We propose here four formal solutions of increasing complexity; the first three of them are conveniently formalized in TLA+ and illustrated by simple examples. The use of a logic-based approach should favor the integration with current Semantic Web technologies, and with Description Logics, and at the same time it should help reducing the gap between formal and informal (natural language) descriptions of services.