Mathematics in Wikidata

Documents from Science, Technology, Engineering, and Mathematics (STEM) disciplines usually contain a significant amount of mathematical formulae alongside text.
Some Mathematical Information Retrieval (MathIR) systems, e.g., Mathematical Question Answering (MathQA), exploit knowledge from Wikidata. Therefore, the mathematical information needs to be stored in items.
In the last years, there have been efforts to define several properties and seed formulae together with their constituting identifiers into Wikidata.
This paper summarizes the current state, challenges, and discussions related to this endeavor.
Furthermore, some data mining methods (supervised formula annotation and concept retrieval) and applications (question answering and classification explainability) of the mathematical information are outlined. Finally, we discuss community feedback and issues related to integrating Mathematical Entity Linking (MathEL) into Wikidata and Wikipedia, which was rejected in 33% and 12% of the test cases, for Wikidata and Wikipedia respectively. Our long-term goal is to populate Wikidata, such that it can serve a variety of automated math reasoning tasks and AI systems.