Fresh-Variable Automata for Service Composition

TL;DR

This paper introduces fresh-variable automata, an extension of finite automata with variable refresh capabilities, to model complex web services involving infinite data domains and sessions, and provides methods for service composition.

Contribution

It presents fresh-variable automata, analyzes their properties, and develops a simulation-based approach for web service composition, extending automata theory to practical service modeling.

Findings

Proved closure properties of fresh-variable automata

Developed decision problem analyses for the automata class

Established a computable simulation-based method for service composition

Abstract

To model Web services handling data from an infinite domain, or with multiple sessions, we introduce fresh-variable automata, a simple extension of finite-state automata in which some transitions are labeled with variables that can be refreshed in some specified states. We prove several closure properties for this class of automata and study their decision problems. We then introduce a notion of simulation that enables us to reduce the Web service composition problem to the construction of a simulation of a target service by the asynchronous product of existing services, and prove that this construction is computable.