Experiments using higher order logic in developing DSN controller software

This paper presents experiments using the higher order logic (HOL) proof system in developing microwave generic controller (UGC) software for the Deep Space Network. These experiments explore various forms of requirements for the Swi-Int (switch interlock) subject of the UGC software formally specified in a CSP-like real-time process algebra embedded in HOL by Peters (see IEEE Wescon/94, Anaheim, CA, September 27-29, 1994). The behavior of the Swi-Int manager is specified graphically in a knowledge graph and as a process algebra formula written in HOL. In an effort to avoid the possibility of livelock in the behavior of the manager, timing constraints are introduced into the design of the manager. As a result, the parallel behavior of the Swi-Int in Peters is refined to incorporate the refinement of the behavior of the manager