[topicmapmail] Reification and Type Instance

[Lars Marius Garshol]

* Robert Cerny
>
> I have a question regarding the TMDM: If i reify a typed statement,  
> is the resulting topic an instance of the type of the statement?

This came up a couple of times in ISO meetings, but was never really  
resolved, partly because in the contexts where it came up, it didn't  
need to be.

But let's try to reason it through, and see where we wind up.

If I say:

employed-by(lmg : employee, bouvet : employer) ~ lmg-employment

then I'm really asserting that the 'lmg-employment' topic represents  
the same thing as the 'employed-by' association. That does kind of  
imply that they should have the same type. It's been argued that the  
statement-type relationship and the type-instance (for topics)  
relationship are different relationships, but I'm not sure that matters.

And if we go on to say

[lmg-employment : employed-by]

that does sound kind of funny, but on the other hand another name for  
'employed-by' is 'employment' and

[lmg-employment : employment]

is perfectly fine.

I can't really find any good reason why it shouldn't be the same  
type. If anyone can I'd be interested to hear it. (Borislav?)

-- 
Lars Marius Garshol                         Mobile: +47 98 21 55 50
Bouvet                                      Office: +47 23 40 60 00