s sl Golog: When conditional compositions of web services meet semantic links and causal laws

Abstract

Web service composition enhanced by semantic technologies is currently one of the most hyped and addressed issues in Service Oriented Computing. This work focuses on both i) conditional composition, i.e., how to automate the composition of services that produces non-deterministic outcomes, and ii) consistent connections between web services (also known as data flows) in the composition. To this end, we suggest the joint use of semantic links and causal laws, respectively, in the area of Description Logics and AI planning. In more detail, an augmented and adapted version of the logic programming language Golog, i.e., s_slGolog, is presented as a natural formalism not only for reasoning about the latter semantic links and causal laws, but also for automatically composing non-deterministic services. s_slGolog operates as an offline interpreter that supports not only binary but also n-ary sensing services (i.e., services conditioned on their possible output parameters) to achieve conditional compositions of services. Lastly, s_slGolog has been implemented and tested in the context of Telecommunication scenarios.