Technical Communications of ICLP 2015. Copyright with the Authors.                        1




   Datalog+/–: A New Family of Languages for
    Knowledge Representation and Reasoning
Thomas Lukasiewicz, Department of Computer Science, University of Oxford, UK
                         (e-mail: thomas.lukasiewicz@cs.ox.ac.uk)




                                        Abstract
Datalog+/– is a recently introduced family of expressive extensions of Datalog for knowl-
edge representation and reasoning. In particular, Datalog+/– allows for representing on-
tological axioms and for query answering under such axioms. The Datalog+/– languages
are derived from Datalog by allowing existentially quantified variables, equality, and the
falsum in rule heads, and, at the same time, by enforcing suitable restrictions to achieve
decidability and tractability. I will give a general overview of the Datalog+/– family of
languages, including complexity results for query answering, main application areas, as
well as extensions for handling inconsistencies, probabilistic uncertainty, and preferences.