[Pellet-users] Check for no subclass

[Bijan Parsia]

On Feb 24, 2008, at 2:58 PM, Bijan Parsia wrote:

> On Feb 24, 2008, at 1:55 PM, Alexander Musidlowski wrote:
>
>> Hi,
>>
>> i think you refer to the sentence "and owl:Nothing is a subclass of
>> every class". As EquivalentClass is a SubProperty of Subclass
>
> I don't know where you got that idea, but it's not true. Neither is
> subclass a subproperty of equivalentclass.

What a brain fart. I get confused by the "property" talk with regard  
to connectives.

"subproperty" just means "only  if"; equivalent means "iff". If A is  
equivClass to B, then A is a subclass of B (and B is a subclass of A).
[snip pretty much ok reasoning but still might be confusing]

>> shouldn´t it also return owl:nothing?
>
> As you can see above, no.
[snip]

If equivalentClass(A,B) then subclass(A,C), NOT if subclass(A,B) then  
equivalentClass(A,B).

So, owl:Nothing being a subclass of a class tells us nothing about  
what its equivalent to. Or, equivalently., what is a subclass of  
owl:Nothing.

So, still no :) I hope this is clearer.

Cheers,
Bijan.