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. More expressions from OWL are planned to be added in the near future.

Features

• Backward Chained reasoning, no overhead added at the import phase.
• Support for rdfs:subClassOf, rdfs:subPropertyOf, rdfs:domain and rdfs:range.
• 4s-query and 4s-httpd accept a "-no-reasoning" flag so to disable the reasoner when needed.
• Support for both single node and clusters configuration.
• Support for SPARQL queries with named graphs, entailed statements are considered part of an entailed virtual graph eGraph. (01/06/2010)

Watch the following demo to get a sense of how 4sr works:

4sr - 4store reasoner demo from Manuel Salvadores on Vimeo.