Aziza, With OWL2, a resource can be both, a class and an individual without going outside of DL. The name for this feature is punning and you can look it up here: http://www.w3.org/TR/2009/WD-owl2-new-features-20090421/. Furthermore, with OWL 2 separation of OWL into Light, DL and Full becomes even less relevant than before. The more meaningful way to look at OWL is through the implementation/deployment prism. With this in mind, OWL 2 provides several profiles of OWL such as OWL RL, OWL EL, etc. You can get more information about this at the link above.
Although punning is possible, from the modeling perspective it is often not a good idea - classes and instances that share the same name do so simply because human languages are fuzzy and ambiguous. People are skilled in interpreting what is said in a correct way based on the various clues and context. For computers, on the other hand, we need precise definitions that are non ambiguous. If you consider the example provided by the OWL2 features document (eagles), it is quite clear that Eagle as a specie (an individual) and Eagle as a class have a good number of entirely different properties. Eagle as a specie may be endangered, and if so, it has a date it was put on a threatened species list. It has sub species such as 'Bald Eagle'. It may have properties such as the population size, etc. None of these properties apply to a given eagle that is a member of the Eagle class. A specific eagle, on the other hand, can have a date of birth, a place of birth, it can have a specific location, like a certain zoo or in a more natural place, etc. These properties do not make sense for a specie, but should be defined for a class. Thus, Eagle the specie and Eagle the class of all eagles are logically different resources. Which brings us to the topic of mirroring. Class-instance mirror pattern is done by using a has value restriction on the class pointing to an individual. For example, let's say you have animals:Eagle a owl:Class and species:Eagle a species:Specie. You then define a hasValue restriction for the animals:Eagle on property animals:specieType to be species:Eagle. Every member of the class eagle will be understood to have a specie type of Eagle and every animal identified as having specie type = species:Eagle will be understood to be a member of the eagle class. This way, the structures are connected and self maintaining through the use of inferencing. Regards, Irene Polikoff -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of aziza Sent: Sunday, October 03, 2010 3:45 AM To: TopBraid Suite Users Subject: [topbraid-users] mirroring instance to class Hi! Could you give me some references about how to use mirrong of instance to class using TopBraid. The thing is, I need to use some concept which occurs to be an instance and a class at the same time. One way of doing it use OWL Full which allows class to be an instance at the same time. But I heard about another way of it - something called mirroring. Can you elaborate on it? Thanks. -- You received this message because you are subscribed to the Google Group "TopBraid Suite Users", the topics of which include TopBraid Composer, TopBraid Live, TopBraid Ensemble, SPARQLMotion and SPIN. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/topbraid-users?hl=en -- You received this message because you are subscribed to the Google Group "TopBraid Suite Users", the topics of which include TopBraid Composer, TopBraid Live, TopBraid Ensemble, SPARQLMotion and SPIN. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/topbraid-users?hl=en
