This paper is about a topic that deserves attention, i.e., how to integrate conventional algorithmic techniques with expert systems to develop programs that need both mathematical computations and heuristics.

Unfortunately, this paper makes little contribution to this topic. The problem of representing and reasoning about control systems is only approached. A frame representation is proposed for describing such systems, but the characteristics of such a frame are really not different from the characteristics of already existing commercial systems. A good point, however, is the use of bond graphs to describe physical systems and their translation into the frame formalism. No real uses of that representation are given and no implementation is mentioned.