> Chen, Jieying. _Knowledge Extraction from Description Logic Terminologies and Its Applications in Industry_. # Knowledge Extraction from Description Logic Terminologies and its Applications in Industry - Justification of $\alpha$: minimal subset $M$ of an ontology $O$ s.t. $M \vDash \alpha$ and $\forall M^\prime \subset M, M^\prime \nvDash \alpha$. - Approximation of all justification: l - Lower-bound = intersection - Upper-bound = union - Naïve, black-box, MUS-membership - Motivation: ontology modularity → signature - Subsumption / deductive module: subset $M$ of $O$ s.t. $\forall \alpha, O \vDash \alpha \implies M \vDash \alpha$ - Algorithms for minimal deductive module computing: - ELH ontologies - ELHr ontologies - ACLH ontologies - $k$-excerpt