[Pellet-users] OWL Class Equivalency

[JPQ]

I have the following:

1. Base.owl - comprised of two named OWL classes that are simply of Type-1
class descriptions.

2. First.owl - a single OWL class, First_Class
       a. First.owl imports Base.owl
       b. First_Class contains property restrictions and a "unionOf" class
description
           (Base:Class_One OR Bass:Class_Two)

3. Second.owl - a single OWL class, Second_Class
       a. Second.owl imports Base.owl
       b. Second_Class contains property restrictions and a "unionOf" class
description
           (Base:Class_One OR Base:Class_Two)

4. First_and_Second.owl is an OWL ontology that simply imports First.owl and
Second.owl

When I run Pellet on "First_and_Second.owl", it draws the following
inferences.

First:First_Class               owl:equivalentClass
Second:Second_Class
Second:Second_Class      owl:equivalentClass             First:First_Class

Here is an excerpt from the OWL reference documentation:

==========

In its simplest form, an equivalentClass axiom states the equivalence (in
terms of their class extension) of two named classes. An example:

<owl:Class rdf:about="#US_President">
  <equivalentClass rdf:resource="#PrincipalResidentOfWhiteHouse"/>
</owl:Class>

NOTE: The use of owl:equivalentClass does not imply class equality. Class
equality means that the classes have the same intensional meaning (denote
the same concept). In the example above, the concept of "President of the
US" is related to, but not equal to the concept of the principal resident of
a certain estate. Real class equality can only be expressed with the
owl:sameAs <http://www.w3.org/TR/owl-ref/#sameAs-def> construct. As this
requires treating classes as individuals, class equality can only be
expressed in OWL Full.

==========

First:First_Class and Second:Second_Class have different intensional
meanings. They share the unionOf class description, but their respective
property restrictions described completely different concepts. Does Pellet
draw an equivalency between these classes solely based on the common unionOf
class description? That is, does Pellet assume there can there be a set of
individuals derived solely from the Base:Class_One and Base:Class_Two
classes, and hence there is a potential equivalency between
First:First_Class and Second:Second_Class?

Thanks.
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