OE Introduction

OE Introduction

The discussion in this section is based on the book "An Introduction to Ontology Engineering" by C. Maria Keet [Keet2020].

Nominals

Page 52: Concepts can be defined by enumerationg its instances. This is not supported natively in Description Logic, but it can be simulated by using nominals. A nominal is a concept that has exactly one instance. Example:Beatle ≡ {john} ⨆ {paul} ⨆ {george} ⨆ {ringo}

Complex Roles

Page 52: Complex roles are derived using constructors such as inverse. We refer to this type of derivation as object property composition. Z.B. istparentOf das Inverse vonchildOf:parentOf ≡ childOf− The author also introduces the empty role and the universal role and remarks that they play a minor role in modeling.

It is interesting to note that, using nominals, a concept assertionMother(julia) can be turned into a concept inclusion{julia} ⊑ Mother and a role assertionparentOf(julia, john) into a concept inclusion{julia} ⊑ ∃parentOf.{john}. This illustrates that the distinction between ABox and TBox does not have a deeper logical meaning