Implementation and Evaluation of a Backtracking Algorithm for Finding All Justifications in OWL 2 EL

Zhangquan Zhou, Guilin Qi

Abstract:

Finding justifications plays an important role in the development and maintenance of ontologies. It helps users or developers to understand the entailments by presenting the minimal subsets of the ontology which are responsible for the entailment (called justification). In our previous work, we have proposed a backtracking algorithm for finding justifications in description logic

$\mathcal{EL}^{+}$
, which underpins OWL 2 EL, a profile of the latest version of Web Ontology Language (OWL). However, the algorithm is not implemented. In this paper, we implement this algorithm and conduct experiments on some real world ontologies, including Snomed-CT. We compare our algorithm with a black-box algorithm for finding all justification in OWL 2 EL. The experimental results show that in most cases, the backtracking algorithm outperforms the black-box one.