[topicmapmail] subject proxies and subject maps

[Johannes Schmidt]

Hi Lars,

thank you for the answer. The question I wish to answer myself is how to 
implement a creation process. In TMDM-conforming applications there is 
no topic "outside" a map. So you first create a map (or "take" an 
existing one), then create a topic and append this topic to it (which is 
one logical step).
If I want to create a subject proxy the following is obviously ok:

class subjectMap
{
   $subjectProxies;
   ...
}

class subjectProxy
{
   $properties;
   ...
}

$sp = new subjectProxy();

Stop.

The interpretation of that lonely proxy $sp as a subject map with one 
proxy is not "in" the application. It is just my interpretation (or 
someone else's). I am not sure if the "problem" is clear. $sp is 
independent from any map and legend, it only exists in the application 
context. So - for example - no navigation operation can be applied as 
navigation operations are relative to subject maps (which means that 
this proxy is inaccessible for a TMQL retrieval, there is only 
application specific access via labels or ids or similar).
More abstracted, the question could be: Are there elements without sets? 
I'm not an expert in set theory ;)

It seems to be useful to implement the interpretation of a lonely proxy 
as a subject map with one proxy explicitly. If not created "in" a 
subject map (whatever this means) put it in a primitive map (which then 
has to be created) without a legend (or provide that "noop" legend) and 
basic ontology. Labelling has to be done in any case.
This would mean: There is no element without a set.

Best regards and a happy new year,
Johannes

Lars Heuer wrote:
> Hi Johannes,
>
>   
>> while thinking about how (and where) to implement a simple dereferencing
>> mechanism for proxies (label -> proxy) I came across the question if 
>> subject proxies can exist independently from any subject map (both 
>> according to TMRM), e.g. in an application (context).
>>     
>
> Well, a subject map is just a container for a finite set of proxies.
> If you want, you can interpret a lonely proxy as a subject map with one
> proxy. I think that's a valid interpretation. The 'bootstrapping'
> ontology (isa, ako) is missing, though. And the legend is also
> missing, if you don't provide a standard "noop" legend.
>
> But you cannot "travel" from a proxy to the containing subject map.
> Nobody forbids to implement such a feature, but the TMRM does not
> provide such a feature.
>
> If you remove a proxy from a subject map, you should take care about
> the relationships to other proxies and you should take care about the
> constraints which the legend mandates.
>
> [...]
>   
>> However, what about the relationship between subject proxies and subject
>> maps (TMRM)? I can not find the answer - an explicit statement - in TMRM
>>     
>
> See above.
>
> Best regards,
> Lars
>