Formal Verification of Web Services Composition Using Linear Logic and the pi-calculus

We give an overview of a rigorous approach to Web Services composition based on theorem proving in the proof assistant HOL Light. In this, we exploit the proofs-as-processes paradigm to compose multiple Web Services specified in Classical Linear Logic, while using the expressive nature of our theorem-proving framework to provide a systematic and rigorous treatment of properties such as exceptions. The end result is not only a formally verified proof of the composition, with an associated guarantee of correctness, but also an 'executable' π-calculus statement describing the composition in process-algebraic terms. We illustrate our approach by analyzing a non-trivial example involving numerous Web Services in a real-estate domain.