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How to distinguish the terms 'primitives' 'axioms' 'expressions' 'basic axioms' 'primitive terms' in description logic / OWL?


I have read several terms in the context of description logic / OWL Web Ontology Language, but it is hard for me to distinguish them. I could not find for any of them a clear definition in the context of the others, and authors use them often without clear definitions. Can someone help me?

The terms are in description logic / OWL:

  • 'primitives'
  • 'axioms'
  • 'facts'
  • 'expressions'
  • 'basic axioms'
  • 'complex axioms'
  • 'primitive terms'
  • 'triple'
  • 'class description'
  • 'class constructors'
  • 'assertion' / 'asserted'

If someone could provide an example then distinguish them or show similarities between, would be very helpful. Thanks in advance!


Solution

  • An axiom is any thing you know to be true in your domain, e.g. the fact that all the dogs are animals.

    A particular kind of axiom is the assertion (or fact), which declares something about specific individuals (e.g. Dog(lessie) or Parent(bob,alice)).

    A triple is a particular way of storing a statements (e.g. <ex:lessie rdf:type ex:Dog>, or <ex:bob Parent ex:alice>, or <ex:Dog rdfs:subclassof ex:Animal>).

    The primitive terms are the entities, such as classes, properties, and individuals.

    A primitive is a particular function used for building class expressions.

    Anyway, some terms (like the adjectives "basic" and "complex") may have different meanings depending on the particular context.