A Denotational Approach to Scope-Based Compensable Flow Language for Web Service

Web Services have become more and more important in these years, and BPEL4WS is a de facto standard for the web service composition and orchestration. We have proposed a language BPEL0 to capture the important features of BPEL4WS, with the scope-based compensation and fault handling mechanism. In this paper we formalize the denotational semantics for BPEL0, which can support the refinement calculus and the verification of program equivalence. A set of algebraic laws is investigated within the denotational framework. The distinct features of BPEL0 make the investigation of the denotational semantics and algebraic laws more challenging.