Unit Knowledge Management

In [9], various observations on the handling of (physical) units in OpenMath were made. In this paper, we update those observations, and make some comments based on a working unit converter [21] that, because of its OpenMath-based design, is modular, extensible and reflective. We also note that some of the issues in an effective converter, such as the rules governing abbreviations, being more linguistic than mathematical, do not lend themselves to easy expression in OpenMath.