Parallel ABox Reasoning of ${\mathcal{EL}}$ Ontologies

In order to support the vision of the Semantic Web, ontology reasoning needs to be highly scalable and efficient. A natural way to achieve scalability and efficiency is to develop parallel ABox reasoning algorithms for tractable OWL 2 profiles to distribute the load between different computation units within a reasoning system. So far there have been some work on parallel ABox reasoning algorithms for the pD* fragment of OWL 2 RL. However, there is still no work on parallel ABox reasoning algorithm for OWL 2 EL, which is the language for many influential ontologies (such as the SNOMED CT ontology). In this paper, we extend a parallel TBox reasoning algorithm [5] for ${\mathcal{ELH_{R+}}}$ to parallel ABox reasoning algorithms for $\mathcal{ELH}_{\bot, \mathcal{R}+}$, which also supports the bottom concept so as to model disjointness and inconsistency. In design of algorithms, we exploit the characteristic of ABox reasonings to improve parallelisation and reduce unnecessary resource cost. Our evaluation shows that a naive implementation of our approach can compute all ABox entailments of a Not-Galen− ontology with about 1 million individuals and 9 million axioms in about 3 minutes.