HajoRijgersberg/OM

Properties with domain/range om:quantity used for subclasses of om:quantity

Opened this issue · 1 comments

jmkeil commented

Currently, commonly has unit is an object property, that is used for many quantity resources. As quantities are classes, this causes punning. This could easily be solved by making commonly has unit an Annotation property.

The properties

have the domain/range om:quantity. This entails that the subjects/objects of according statements are instances of om:quantity (which represent what is called a quantity in JCGM 2012). However, they are used for subclasses of om:quantity (which represent what is called a kind of quantity in JCGM 2012).

That way, this entails that many IRIs represent both, a kind of quantity and a quantity. Due to punning, these kinds of quantity and quantities are treated under OWL 2 Direct Semantics / OWL 2 DL reasoning as separate entities with the same IRI, so this does not logical contradict the (not modeled) disjointedness of kind of quantity and a quantity. But it is still an unintended entailment and in my view a flaw in the T-Box.

Under the assumption that no logical consequences are expected from these properties (i.e. they are mainly intended for user information), it would be a solution to

  • remove the according domain/range statements (to avoid the unintended classification), and to
  • reclassify them from owl:ObjectProperty into owl:AnnotationProperty (to avoid the punning at all).

Similar problems affect om:has base quantity, om:has derived quantity, and om:uses quantity.

I rewrote the issue above.