An Interface Theory for Input/Output Automata

Abstract

Building on the theory of interface automata by de~Alfaro andHenzinger we design an interface language for Lynch&#39;s Input/OutputAutomata, a popular formalism used in the development of distributedasynchronous systems, not addressed by previous interface research.We introduce an explicit separation of assumptions from guaranteesnot yet seen in other behavioral interface theories. Moreover wederive the composition operator systematically and formally,guaranteeing that the resulting compositions are always the weakestin the sense of assumptions, and the strongest in the sense ofguarantees. We also present a method for solving systems ofrelativized behavioral inequalities as used in our setup and draw aformal correspondence between our work and interfaceautomata. Proofs are provided in an appendix.<br /