The doloop considered harmful in production system programming

In this paper we focus on some aspects of Expert System programming. In particular we consider some of the language constructs which forri'l part of a new production system language known as Herbal:.~ac we are developing at Columbia University. These language consmlCts greatly increase the::x;;ressiveness of a typical produc:::on system language and can be efficiently exec~t.ed on a par::111el:nachlne. We briefly describe the DADO machine under development at Columbia University and J basic algorithm for production system execution for that machine. We conclude with a discussion of some performance Statistics recently calculated from m _analysis of production systems simulations and describe the expected effects of our added language constructs on these statistics