A description logic knowledge base is the equivalent of a theory in first-order logic or an ontology in OWL.
Definition (Knowledge Base). A DL knowledge base K is a triple ⟨T, A, R⟩ where
- T is a set of terminological axioms (TBox)
- A is a set of assertional axioms (ABox)
- R is a role box (RBox)
Note that in the literature the knowledge base definition often includes the TBox-ABox pair only, which corresponds to OWL ontologies, and does not include an RBox. For very expressive description logics, the definition includes the RBox as well.