rdfsemantic-websemanticsinterpretation

Does the set LV only contains untyped literals?

I'm reading the book Foundations of Semantic Web Technologies. One concept really confuses me.

In the definition of a simple interpretation I, it says that IL maps the typed literals from V into the set IR of resources and LV, a particular subset of IR, called the set of literal values, containing (at least) all untyped literals from V. It seems to me that the result of mapping IL is a subset of LV. But in the diagram, which means to explain these definitions, only untyped literals map to the set LV while the mapping IL points from the typed literals to the whole resources set.

The Figure from the book

The Figure from the book

Solution

  • Literals without an explicit type have the PlainLiteral type assigned to them during parsing (in OWL 2), so they are a subset of typed literals. This is compatible with OWL 1, even if at the time they wouldn't have any type at all.