An ABox Revision Algorithm for the Description Logic $\mathcal{EL_{\bot}}$

ABSTRACT. Revision of knowledge bases expressed in Description Logics (DLs) has gained a lot of attention lately. Existing revision algorithms can be divided into two groups: model-based approaches (MBAs) and formula-based approaches(FBAs). MBAs are independent of the syntactical forms of the knowledge base, and are fine-grained for the changes between knowledge bases; however, they only work for some restricted forms of the DL-Lite family. FBAs can deal with expressive DLs such as $\mathcal{SHOIN}$, but they are syntax-dependent and not fine-grained. In this paper, by combining MBAs and FBAs in some form, we present a new method for revising DL-based knowledge bases in the instance level. In our algorithm, a typical model is firstly constructed for the knowledge base to be revised; then a revision process based on justifications is carried out on this model by treating this model as a set of assertions; finally the resulted model is mapped back to a knowledge base which will be returned by the algorithm. Our algorithm are not only syntax-independent and fine-grained, but also works well for the description logic $\mathcal{EL_{\bot}}$ which extends $\mathcal{EL}$ with bottom concept.