Re: On Formal IS-A definition

From: Reinier Post <rp_at_raampje.lan>
Date: 29 Apr 2010 22:31:58 GMT
Message-ID: <4bda08dd$0$14133$703f8584_at_textnews.kpn.nl>



Tegiri Nenashi wrote:

[...]

>Animals = [Name]
> bear
> sheep
> wolf
>;
>
>Carnivores2 = [Name Prey]
> bear deer
> wolf sheep
> wolf deer
>;
>
>I suggest that we still have "Carnivores2" IS-A "Animals". Do you
>agree?

No. I've never seen this. The naming of Carnivores2 is strange: it should name what each tuple stands for, but a carnivore isn't always represented by a single tuple.

Suppose we have

 Herbivores = [Name Foodtype]

              deer  grass
              rabbit grass
              rabbit carrots

and

 Vegetables = [Foodtype]

              grass
              carrots

Would you say that Herbivores IS-A Animals? What about Herbivores IS-A Foodtype? If not, why not?

-- 
Reinier
Received on Thu Apr 29 2010 - 17:31:58 CDT

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