- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Wed, 21 Aug 2002 07:07:45 -0400
- To: phayes@ai.uwf.edu
- Cc: www-webont-wg@w3.org
Again, as far as I can see
John rdf:type Student .
John rdf:type Employee .
does not entail
John rdf:type _:w .
_:w owl:intersectionOf _:l1 .
_:l1 owl:first Student .
_:l1 owl:rest _:l2 .
_:l2 owl:first Employee .
_:l2 owl:rest owl:nil .
because there is no requirement that there be an element of the domain of
discourse whose class extension is the intersection of Student and
Employee.
For example, the following is a GHOWL interpretation of the premise
S = { j, x, y, t, s, e } + other built-ins + sequence
I(John) = j
I(rdf:type) = t
I(Student) = s
I(Employee) = e
ICEXT(Student) = { j, x }
ICEXT(Employee) = { j, y }
plus built-in class extensions
builtin in property extensions
This interpretation is *not* an interpretation of the consequent, because
there is no class in the interpretation whose extension is { j }, and thus
there is no <x,S([Student,Employee])> in IEXT(I(owl:intersectionOf)).
Peter F. Patel-Schneider
Bell Labs Research
Received on Wednesday, 21 August 2002 07:07:55 UTC