Re: TMQL - Proposal: Removal of reifier axis

Andrew,

On 5/1/2011 6:42 AM, Andrew S. Townley wrote:
> Hi Lars, Patrick,
>
> On 1 May 2011, at 09:39 a.m., Lars Heuer<[email protected]>  wrote:
>
>> Hi Patrick,
>>
>> [...]
>>>> If a topic reifies association A and A has an item identifier B and
>>>> the topic has an item identifier C. What's the result for the "item
>>>> identifier" axis? B and C? Or is it B in the context of the
>>>> association and C in the context of the topic?
>>>>
>>> Good question. Don't know.
>> [...]
>>
>> I think the answer should be [B, C] in any case since the assoc and
>> the topic represent the same thing.
> I'd agree with this too--especially given the way the implicit merging stuff works in TMDM. Subject indicators and subject locators are specific reifiers with given semantics. Both trigger merging in the effective map based on the spec, so you could reasonably expect similar things like your proposal to take place given the logical merge implied by reification of an association.
>
> The main problem I see is that your proposal makes subject proxies in the general sense first-class citizens in the TMDM. Once this happens, there's no longer a need for the distinction of constructs that can only have terminal property values (TMDM topics) and constructs that can only have non-terminal property values - what I call links (TMDM associations).  This would therefore invalidate a number of fundamental assumptions baked into TMDM systems, and I think that makes it a non-runner (in addition to rather unpopular). ;)
>
How does that "invalidate" the fundamental assumptions baked into TMDM 
systems?

They operate just as they did before but with an operator that returns 
more complete information (the identifier for both the assoc and its 
reifying topic).

So, before we declare something "unpopular" let's at least describe it 
accurately.

>> The more I think about the removal of an explicit reifier axis the
>> more I love this proposal. ;) I think it brings us a step towards your
>> TMDM-NG proposal [1], at least on the syntax/mental level. You can ask
>> *any* Topic Maps construct about names, occurrences etc. Lovely. :)
>>
>> [1]<http://tm.durusau.net/?p=2893>
> Thanks for the pointer. I hadn't seen this. Very interesting. In many respects, this is part of what I'm trying to do with Pragmantix, but probably keeping fewer TMDM assumptions.
>
Be mindful that *blind interchange* in based on standardized 
assumptions. I suspect the fewer of assumptions you have, the higher the 
cost of interchange.

I think topic maps need to support domain-based, assumption laden models 
as well as more flexible and open-ended approaches, as well as steps in 
between.

I would like to think that if my blog has illustrated anything, it is 
that the world is a very big and complicated place.

Hope you are having a great weekend!

Patrick




> Have a good rest of the weekend.
>
> ast

-- 
Patrick Durusau
patrick-Q/[email protected]
Chair, V1 - US TAG to JTC 1/SC 34
Convener, JTC 1/SC 34/WG 3 (Topic Maps)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)

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