Wikidata Constraints on MARS (Extended Technical Report)
  Wikidata constraints, albeit useful, are represented and processed in an
incomplete, ad hoc fashion. Constraint declarations do not fully express their
meaning, and thus do not provide a precise, unambiguous basis for constraint
specification, or a logical foundation for constraint-checking implementations.
In prior work we have proposed a logical framework for Wikidata as a whole,
based on multi-attributed relational structures (MARS) and related logical
languages. In this paper we explain how constraints are handled in the proposed
framework, and show that nearly all of Wikidata's existing property constraints
can be completely characterized in it, in a natural and economical fashion. We
also give characterizations for several proposed property constraints, and show
that a variety of non-property constraints can be handled in the same
framework.
