Using the theorem prover SETHEO for verifying the development of a communication protocol in FOCUS -A Case Study-

Abstract

This paper describes experiments with the automated theorem prover SETHEO. The prover is applied to proof tasks which arise during formal design and specification in Focus.

These proof tasks originate from the formal development of a communication protocol (Stenning protocol). Its development and verification in Focus is described in “C. Dendorfer, R. Weber: Development and Implementation of a Communication Protocol — An Exercise in Focus” [DW92a]. A number of propositions of that paper deal with safety and liveness properties of the Stenning protocol on the level of traces. All given propositions and lemmata could be proven automatically using the theorem prover SETHEO.

This paper gives a short introduction into the proof tasks as provided in [DW92a]. All steps which were necessary to apply SETHEO to the given proof tasks (transformation of syntax, axiomatization) will be described in detail. The surprisingly good results obtained by SETHEO will be presented, and advantages and problems using an automated theorem prover for simple, but frequently occurring proof tasks during a formal development in Focus, as well as possibly ways for improvements for using SETHEO as a “back-end” for Focus will be discussed.

This work has been carried out within the Sonderforschungsbereich SFB 342 “Werkzeuge und Methoden für die Nutzung paralleler Rechnerarchitekturen” funded by the Deutsche Forschungsgemeinschaft.