An educational version of a symbol manipulation language
William E. Kennedy · 1975
One important aspect of non-numerical programming has been the development of systems for symbolic mathematics. As an example, Collins' SAC-I package is a powerful, highly portable, and efficient system for symbolic and algebraic computation. General application of these systems, however, has sometimes been hampered because efficiency considerations necessitated limited diagnostic facilities. Hence, users having little experience with such systems often had great difficulty debugging programs. This paper discusses an educational version of the SAC-1 List Processing module, i.e., an implementation which provides extensive error checks, diagnostic messages, and debugging facilities not found in the production version of SAC-1. The implementation has proven very valuable as a learning aid for a broad spectrum of users, from beginning data structures students to high-level applications programmers.