Re: Chainsaw?

At 07:18 AM 10/20/00 -0700, Seth Russell wrote:
>Graham Klyne wrote:
>
> > My problem is this:  when [FordEscort] refers to [TheBody] and [TheEngine]
> > in reference to my car, how can I infer that these statements refer to
> > parts of my car rather than some other person's Ford Escort car?
>
>Well when statements are in the context of [MyCar] they just refer to your
>instance of [FordEscort].
>
>[MyCar] --isa--> [FordEscort]
>[     ] --ist-->
>    {
>    [TheBody] ----colour----> "Red"
>    [TheEngine] --capacity--> "1600"
>    [TheEngine] --needs---->[repair]
>     :
>    (etc.)
>    }
>
>What's wrong with that?

I guess there's nothing wrong with it that I can put my finger on, but it 
doesn't quite match the way I'm trying to do things.  I'm trying to pursue 
the idea of contexts as a tool for structuring complex descriptions.  (If 
that is a bad idea, I'm hoping someone will say, and explain why.)

Your reference above to "instance of [FordEscort]" implies that it is a 
type or class.  Maybe my use of 'isa' property name when the object is not 
(intended to be) a class did not help.  Maybe I should have written:

   [MyCar] --Model--> [FordEscort]

I want to treat [FordEscort] as a resource that has various properties that 
describe that model of car, and, by reference, to have those properties 
apply to my car.

Maybe [FordEscort] should be an rdf:Class?  I'm not quite comfortable with 
the idea that the model may be a class (hence object of rdf:type) and also 
an "ordinary" resource in its own right with lots of properties relating to 
some physical entity.

#g

------------
Graham Klyne
(GK@ACM.ORG)