Fluent Calculus-Based Semantic Web Service Composition and Verification Using WSSL

We propose a composition and verification framework for Semantic Web Services specified using WSSL, a novel service specification language based on the fluent calculus, that addresses issues related to the frame, ramification and qualification problems. These deal with the succinct and flexible representation of non-effects, indirect effects and preconditions, respectively. The framework exploits the unique features of WSSL, allowing, among others, for: compositions that take into account ramifications of services; determining the feasibility of a composition a priori; and considering exogenous qualifications during the verification process. The framework is implemented using FLUX-based planning, supporting compositions with fundamental control constructs, including nondeterministic ones such as conditionals and loops. Performance is evaluated with regard to termination and execution time for increasingly complex synthetic compositions.