The Semantic Web Rule Language Expressiveness Extensions-A Survey
  The Semantic Web Rule Language (SWRL) is a direct extension of OWL 2 DL with
a subset of RuleML, and it is designed to be the rule language of the Semantic
Web. This paper explores the state-of-the-art of SWRL's expressiveness
extensions proposed over time. As a motivation, the effectiveness of the
SWRL/OWL combination in modeling domain facts is discussed while some of the
common expressive limitations of the combination are also highlighted. The
paper then classifies and presents the relevant language extensions of the SWRL
and their added expressive powers to the original SWRL definition. Furthermore,
it provides a comparative analysis of the syntax and semantics of the proposed
extensions. In conclusion, the decidability requirement and usability of each
expressiveness extension are evaluated towards an efficient inclusion into the
OWL ontologies.
