[sc34wg3] SAM-issue psi-generics (was: SAM-issue term-scope-def)

[Lars Marius Garshol]

* Bernard Vatant
| 
| Let M be the topic representing in a topic map the subject
| "Marc-de-Graauw-the-guy-outhere" Let M1 be the topic representing
| the subject "M-element-of-this-serialized-topic-map"
| [...] 
| Now you can rewrite without problem nor ambiguity your assertions,
| replacing your original topic 'Marc' by M in 1,2, and 3, and by M1
| in 5 and 6. 

This is correct. We all agree on this.

| [4. 'Marc is an instance of class topic' ]
|
| And of course 4 is valid for both M and M1 ... a topic is a topic :)

This is where we don't agree at all. Either M represents Marc, or it
represents the topic "Marc". If it represents Marc then it is false to
say that Marc is a topic. In other words, 4. is false when applied to
Marc. 

To see why this is so, go back to the first three statements:

* Marc de Graauw
|
| 1.  'Marc has a name "Marc de Graauw" '
| 2.  'Marc has one wife'
| 3.  'Marc has two sons'

Now, the topic "Marc" doesn't have a wife, so obviously 2. is a
statement about the subject, and not about the topic. Note that there
are two levels here:

  1. The topic map level: The topic representing Marc has an
  association with the topic representing Marc's wife.

  2. The subject level: Marc has a relationship (marriage) to his
  wife.

Clearly 

  marriage(marc : husband, marcs-wife : wife)

is an instance of 1. representing 2. And just as clearly, at the
subject level it is a statement about Marc, and not about the topic
"Marc".

Perhaps this becomes even clearer if we say

  [marc : person]

We've now said that Marc is an instance of person. Clearly, we are
talking about the subject, not the topic. So if we also say

  [marc : topic]

we are lying.

Of course, if we were to create

  [marc-topic]

then we couldn't say

  [marc-topic : person]

because the subject of this topic isn't a person but a topic. What we
can say is

  [marc-topic : topic]

Now, if it is false to say that [marc-topic : person], why isn't it
false to say [marc : topic]? 
 
| No. All assertions are about topics, but about two different topics
| (representing different subjects)

Eh, no. All the assertions are about subjects, but using two different
topics to represent the two different subjects. We don't create topic
maps to talk about topics, we create them to talk about subjects.
Otherwise nobody would care the slightest about them.

-- 
Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
ISO SC34/WG3, OASIS GeoLang TC        <URL: http://www.garshol.priv.no >