OpenMath Content Dictionaries for SI Quantities and Units

We document the creation of a new set of OpenMath content dictionaries to support the expression of quantities and units under the International System of Units (SI). While preserving many of the concepts embodied in the original content dictionaries, these new content dictionaries provide a foundation for quantities and units that is compliant with international standards. We respond to questions raised in prior efforts to create content dictionaries for units and dimensions by proposing and applying some rationalized criteria for the creation of content dictionaries in general. The results have been released and submitted to the OpenMath website as contributed content dictionaries.