Are literals owl:Things?

Semantic Web Mailing List,

I was recently asked a question by a former colleague about whether  
literals are considered owl:Things.  Initially, my intuition was that  
literals are rdfs:Resources but they are not owl:Things.  However,  
having looked into the matter more closely, I think I have come to a  
different conclusion which I would like to sanity check with the  
semantic web community.  Are the following statements true?


Under OWL 1 Direct Model-Theoretic Semantics, literals are not  
owl:Things.
(EC(owl:Thing) = O where O is a subset of R that is disjoint from LV  
[1].)

Under OWL 1 RDFS-Compatible Semantics, literals are owl:Things for OWL  
1 Full and not for OWL 1 DL.
(CEXT_I(S_I(owl:Thing)) = IOT [2], where IOT = R_I for OWL Full [3]  
and IOT is disjoint with LV_I for OWL DL [4].)

Under OWL 2 Direct Semantics, literals are not owl:Things.
((owl:Thing)^C = \Delta_I where \Delta_I is disjoint with \Delta_D [5].)

Under OWL 2 RDF-Based Semantics, literals are owl:Things.
(ICEXT(I(owl:Thing)) = IR [6].)


[1] http://www.w3.org/TR/owl-semantics/direct.html#3.1
[2] http://www.w3.org/TR/owl-semantics/rdfs.html#5.2
[3] http://www.w3.org/TR/owl-semantics/rdfs.html#5.3
[4] http://www.w3.org/TR/owl-semantics/rdfs.html#5.4
[5] http://www.w3.org/TR/owl2-direct-semantics/#Interpretations
[6] http://www.w3.org/TR/owl2-rdf-based-semantics/#Semantic_Conditions_for_the_Vocabulary_Classes


Jesse Weaver
Ph.D. Student, Patroon Fellow
Tetherless World Constellation
Rensselaer Polytechnic Institute
http://www.cs.rpi.edu/~weavej3/index.xhtml