in OWL2DTDL/DotNetRdfExtensions.cs [302:309]
public static bool IsSimpleXsdWrapper(this OntologyClass oClass)
{
if (oClass.IsDatatype() && oClass.EquivalentClasses.Count() == 1)
{
return oClass.EquivalentClasses.Single().IsXsdDatatype();
}
return false;
}