[Pellet-users] Inferred Subsumption

[JPQ]

I'm running the Pellet inferencing engine in TopBraid Composer on a valid
OWL-DL document. Here are the details.

An OWL-DL ontology contains the following class.
<owl:Class rdf:ID="LatLon">
   <owl:unionOf rdf:parseType="Collection">
      <rdf:Description rdf:about="Another_Ontology.owl#Lat"/>
      <rdf:Description rdf:about="Another_Ontology.owl#Lon"/>
   </owl:unionOf>
</owl:Class>

The anonymous class formed by the "unionOf" set operation is equivalent to
the named class, "LatLon".

This ontology imports a second ontology.

The second OWL-DL ontology ("Another_Ontology") has the following features:

1. The "Lat" & "Lon" classes are Type-1 OWL classes (ie, they are simply
identified as RDF nodes using the rdf:ID construct)
2. There exist "lat" & "lon" datatype properties
    a. The "lat" property domain is "Lat"; its range is "xsd:double". The
same applies with "lon",
        except its domain is "Lon".
        (I've also tried an alternate version where the "lat" & "lon"
datatype properties only define
        ranges and not domains.)

    b. Both the "lat" & "lon" datatype properties are also typed with
<owl:FunctionalProperty>

 Running the Pellet inference engine on the first ontology results in the
following inferences.
      Another_Ontology:Lat rdfs:subClassOf LatLon
      Another_Ontology:Lon rdfs:subClassOf LatLon

The "LatLon" class subsumes "Lat" & "Lon".

Why does Pellet infer these subsumptions when the "LatLon" class description
defines an equivalency?

Thanks for your help.
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