PRESS (PRolog Equation Solving System) is a program that uses heuristic reasoning to automatically solve systems of elementary equations like those given in General Certificate of Education A-level examinations at British universities. This paper describes at a rather high level the different steps used by this solving system to tackle different aspects of the problems and provides some meta-level concepts, which are used to decide which steps to apply at what time. In addition, the paper gives performance results, which show how well a job is performed (for instance, the equation log2x + 4logx2 = 5 is solved in 4.5 seconds on a Sun 3/160 using Quintus Prolog). The paper, however, does not provide extended comparison to related systems (such as MACSYMA or SCRATCHPAD).
The research reported in this short paper dates back to 1974 with the first version of the PRESS program written by some of the authors. Thus, although a revised version of this program is described, readers can hardly expect to discover new results there. This paper would, however, be of interest to anyone wishing to learn more about these kinds of symbolic manipulation systems.
The paper is very well written and easy to read. I noticed no typos or mistakes except a minor font glitch on page 72.
