The isAlso rdfs:ConstraintProperty

Pierre-Antoine CHAMPIN wrote:
> Jonas Liljegren wrote:
> > ** isAlso
> >
> > I have also found the need to say that objects of a certain type must
> > also be of certain other type. That is: a instance with multiple
> > classes. Not a class that inherits from many classes.
> >
> > isAlso  -  A resource of this type must also be a of that other type
> >     type rdfs:ConstraintProperty
> >     domain rdfs:Class
> >     range rdfs:Class
> this is exactly the same :
> suppose class A isAlso B
> then any instance of A is an instance of B,
> then A is *structurally* a subclass of B !

It seems that way, but it is not.

As an example:

    type rdfs:Class
    isAlso B_Class

    type AbstractClass

    subClassOf B_Class

    type A_Class
    type C_Class

The object follow the constraint introduced by beeing an instance of
A_Class.  The constraint is that it also has to be _some_type_of_
B_Class. But it doesn't say what class.

If A_Class was a subClassOf B_Class, you had no way of saying that
that objecyt also should be of type C_Class or some other subClassOf

This may not be the ususal way to solving this problem. But I like the
freedom of inventing my own OO. :-)

/ Jonas  -

Received on Tuesday, 20 June 2000 06:04:09 UTC