Re: Is it a redundancy? Indetected inconsistency?

I am trying to make sense of your axioms, but they do seem rather odd. Comments in-line.

On Mar 9, 2015, at 7:43 PM, Leila Bayoudhi <bayoudhileila@yahoo.fr> wrote:

> Hi,
> Having already:
> subClassOf(person animal)
> DisjointClasses(woman animal )

What is your intention with these axioms? On the face of things they seem rather confused. If people are animals, why would women *not* be animals? This is technically consistent, but only by not having women be people, which is hardly a politically correct view of the fairer sex, and in any case you treat men in the same way:

> DisjointClasses(man animal)

So now anything in the classes man or woman cannot be an animal, so cannot be a person. Is this what you intended?

> 
> We want to introduce subClassOf (person ObjectUnionOf(woman man)
> This may introduce inconsistency.

It should not, since these are consistent. For example, if all the classes man, woman and person are the empty class, then all four sentences are true (since the empty class is a subclass of any class.) So they do have a satisfying interpretation, albeit one which describes a rather grim view of things, in which human beings are extinct. 

> So, we choose as a solution to  introduce a subClassOf (person ObjectUnionOf(animal ObjectUnionOf(woman man)).

That is also true under the no-people interpretation, since the empty class is a subclass of its union with itself.

> According to protegé, the ontology is no longer inconsistent. However, it seems as if the ontologist wants at the end to say that:
> subClassOf (person ObjectUnionOf(woman man): Is it correct what i am saying?

I really don't quite know what you are saying, to be honest. Your axioms are all consistent, but they do not make intuitive sense, unless you are trying to say that there aren't any people; but then why bother to introduce the men and women classes?

Can you write out  just in plain English sentences what it is that you are intending to say? 

Pat Hayes

> If it is not: is it problem of my proposed solution for maintaining consistency?
> Am I introducing redundant axioms(though OWL 2 DOES NOT care for this, I care).
> 
> Thx for answering me those questions?
> 
> 

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Received on Tuesday, 10 March 2015 03:17:19 UTC