[topicmapmail] Superclass-subclass indentation in the Omnigator

[Robert Barta]

On Fri, Dec 20, 2002 at 01:18:55PM +0000, Murray Altheim wrote:
> Steve Pepper wrote:
> [...]
> 
> > The other problem is that of confusing superclass-subclass with
> > class-instance, as the following example illustrates:
> >
> > (1)  Steve is a homo sapiens       (1a)
> >      A homo sapiens is an ape      (1b)
> >      Therefore Steve is an ape
> >
> > (2)  Steve is a homo sapiens       (2a)
> >      Homo sapiens is a species     (2b)
> >      Therefore Steve is a species
> >
> > The conclusion drawn in (1) is correct, whereas that drawn in (2)
> > is not. Why? Because (1b) is a superclass-subclass relationship,
> > whereas (2b) is a class-instance relationship. They look almost
> > identical, but they have quite different semantics and properties.
> 
> Actually, Steve, you are not an ape. You are a human.
> 
> A bit of background:
> 
>   Kingdom Animalia
>     Phylum Chordata
>       Class Mammalia
>         Order Primates
>           Superfamily Hominoidea
>             Family Pongidae
>               Genus Homo
>                 Species Homo sapiens

As this is in fact always a major gotcha in my student's maps
I tried to get a clean presentation of this issue at

    http://topicmaps.it.bond.edu.au/docs/16/toc

Please feel free to complain loudly if I miss the point there.

\rho