XRay: A Prolog Technology Theorem Prover for Default Reasoning: A System Description

XRay is a theorem prover for default logics. Its deductive power is primarily due to our approach of integrating default reasoning into existing model elimination based provers using the well-known PTTP approach. We conceived and integrated a number of enhancements, such as lemma handling, regularity-based truncations of underlying search spaces and a model-based approach to consistency checking.