4sr is an extension of 4store where we are implementing backward chained reasoning. Currently a subset of RDFS is supported. This set includes: rdfs:subClassOf, rdfs:subPropertyOf, rdfs:domain and rdfs:range.
D. Tsarkov, and I. Horrocks. Proc. of the Int. Joint Conf. on Automated Reasoning (IJCAR 2006), volume 4130 of Lecture Notes in Artificial Intelligence, page 292--297. Springer, (2006)
I. Horrocks. Principles of Knowledge Representation and Reasoning: Proceedings of the Sixth International Conference (KR'98), page 636--647. Morgan Kaufmann Publishers, San Francisco, California, (June 1998)\\ http://www.cs.man.ac.uk/~horrocks/Publications/ \\ download/1998/kr98.ps.gz.