Unique Name Assumption

[Ed Shaya]

It does not seem to me to be a good idea to make individual 
elements/atoms instances in the first place.  What if someone needs to 
refer to a specific atom sitting in their Atomic Force Microscope (AFM)? 
  For this you would want to make an individual of the Class Carbon.
<Carbon rdf:ID="MyCarbonAtom"/> where Carbon is a class.  This also 
makes it possible to add isotopic species as subclasses.  We should 
refrain from using individuals except for a named individual in the 
universe: Earth, Algol, M31, Mike Brown, MyBigRedChair.

One still should make the various types of atoms owl:disjointWith, but, 
as I mentioned previously, we really need a new version of OWL to make 
this more manageable because nearly every class is distinct from every 
other class in astronomy.  In any event the only loss if you do not use 
disjointWith is that a reasoner can not spot an error if someone tries 
MyCarbonAtom is both Carbon and Silicon.

Ed


Thanks, Elyes for pointing out a weakness here.
Ed


Elyes Lehtihet wrote:
> Hello,
> 
> While exploring the AstroOntology, I have noticed that you create a set 
> of individuals (instances) of the AtomicElement, SpectralType, etc. As 
> you probably know, the web ontology language use the Unique Name 
> Assumption: every concept is not, by default, necessary distinct from 
> the others. It implies that the instances of your classes are not made 
> 'explicitly' distinct for the reasoners : Carbon is not explicitly 
> distinct from Calcium, etc. etc.
> 
> The common pattern to solve this problem is to create an 
> 'owl:AllDifferents' axiom (Protégé: OWL/Edit owl:AllDifferents...) that 
> regroups the set of instances. After, one should create a new expression 
> to enumerate the allowed values of the class. Example for the 
> LuminosityClass: {LuminosityClassII LuminosityClassV LuminosityClassIII 
> LuminosityClassIV LuminosityClassI}
> This method assumes that a Class cannot take other values than the ones 
> explicitly defined by the enumeration - But maybe there are more 
> AtomicElement than the 14 that are cited :-)
> 
> Best regards,
> Elyes
> 
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