[sc34wg3] Re: [topicmapmail] Multiple scopes on associations

[Lars Marius Garshol]

* Lars Marius Garshol
|
| I think I've understood this now. You want to know what happens when a
| <mergeMap> element with added themes refers to a topic map containing
| an association with a non-empty scope.

* Martin Bryan
| 
| Exactly. My concern is that both added themes and local scopes can refer to
| multiple topics (sets of topics) and the question that seems to have arisen
| is one about whether or not combining these creates a set of sets, or a
| single set.

Uh, no. The issue is what happens when

  <topicMap>

    [...]

    <association>
      <instanceOf>
         <topicRef xlink:href="#A"/>
      </instanceOf>
      <scope>
         <topicRef xlink:href="#THEME1"/>
      </scope>

      <member>
        <roleSpec>
           <topicRef xlink:href="#B"/>
        </roleSpec>
        <topicRef xlink:href="#C"/>
      </member>     

      <member>
        <roleSpec>
           <topicRef xlink:href="#D"/>
        </roleSpec>
        <topicRef xlink:href="#E"/>
      </member>     
    </association>

    <association>
      <instanceOf>
         <topicRef xlink:href="#A"/>
      </instanceOf>
      <scope>
         <topicRef xlink:href="#THEME2"/>
      </scope>

      <member>
        <roleSpec>
           <topicRef xlink:href="#B"/>
        </roleSpec>
        <topicRef xlink:href="#C"/>
      </member>     

      <member>
        <roleSpec>
           <topicRef xlink:href="#D"/>
        </roleSpec>
        <topicRef xlink:href="#E"/>
      </member>     
    </association>
  </topicMap>

is read in by a topic map processor. Do we get one association with
two scopes, or two associations with one scope each? 13250, XTM 1.0,
the infoset model, current topic map engines all think the latter,
PMTM4 thinks the former.

| So as I understand it there is no difference between any of the
| models. 

That's right.

| The only difference is whether or not two different sets of
| scopes/themes attached to associations that link the same topics
| using the same association identifier are considered to be the same
| association with multiple scopes or a set of associations. 

If this means the same as my XTM fragment above then yes.

| My question then is "Does it really matter which way applications
| store the data, as long as we understand that a given pair of topics
| can be linked by the same association type multiple times in
| different scopes?". (For example, A can be married to B more than
| once. As long as the scope of each marriage is differentiated then
| there should be no problems distinguishing them.)

I'm not sure what I think of this, to be honest. If you and SRN battle
it out I may be able to decide which side I'm on.

--Lars M.