Re: TMRM: isa/sub - irreflexive relation vs. reflexive relation

Hi Robert,

[...]
>    lheuer isa lheuer

> would undermine that idea. It would make lheuer an individual, and
> also a class (on its own).

Yep. Well, a technology I heard of (iirc it is called RDF) uses it:

     rdfs:Class isa rdfs:Class

> One can still assert it explicitly, but
> according to TMRM it would not appear intrinsically.

So it would be valid to add a statement x isa x to a TMRM map?

According to my understanding of section 5. b) it is explicitly
forbidden since it states:

    """
    The isa relationship is supposed to be non-reflexive, i.e. x isa x
    for no x element of m, so that no proxy can be an instance of
    itself.
    """"

If x isa x is allowed, we'd get: "x isa x for a subset of m".

Maybe the paragraph is misleading since it defines the *predefined*
environment of TMRM and "x isa x for no element of m" holds true for
the predefined environment but may not hold true for an individual map
once the user adds statements which contradict "x isa x for no element
of m".

Best regards,
Lars
-- 
Semagia 
<http://www.semagia.com>

<http://www.topicmaps.de/mailinglist/> German Topic Maps mailing list
<http://tinytim.sourceforge.net/> Open Source Topic Maps engine
<http://mappa.semagia.com/> Mappa - Python Topic Maps engine