The HermiT OWL Reasoner

HermiT is the only reasoner we know of that fully supports the OWL 2 standard, and that correctly reasons about properties as well as classes. It is based on a novel “hypertableau” calculus that addresses performance problems due to nondeterminism and model size—the primary sources of complexity in state-of-the-art OWL reasoners. HermiT also incorporates a number of novel optimizations, including an optimized ontology classification procedure. Our tests show that HermiT performs well compared to existing tableau reasoners and is often much faster when classifying complex ontologies.