[sc34wg3] Documenting merging rules in TMDM

Steve Pepper sc34wg3@isotopicmaps.org
Sat, 13 Mar 2004 16:16:27 +0100

* Patrick:

| Just a quick reply with more to follow.

Answers to my questions in your capacity as leader and
spokesperson for the US National Body, I hope? :-)

| There is a difference between:
| 1. Merging rules written in a known syntax (your case)
| and,
| 2. Merging rules that are embedded in an application.
| The first allows a customer to make a reasoned judgment of cost and risk 
| in migrating from one topic maps software application to another.
| The second does not.
| Does that help?

Help in which way? I agree with this entirely, so it establishes
that we are on the same page in that regard: Documenting merging
rules is preferable to not documenting them.

But are you saying that you would accept Kal's approach, even
though it delegates responsibility for defining how to document
merging rules to TMCL?

| (Curious why I need TMCL to express: "X is true of topic A and Y is true 
| of topic B then topic A and topic B must be merged." The TMDM already 
| has 'X is true of topic A and X is true of topic B then topic A and 
| topic B must be merged.' Is there some reason why I need a separate 
| mechanism for X and Y? Other than a particular implementation strategy?)

Well, you said it yourself. The TMDM allows you to express "if X is true
of *both* A and B then A and B must be merged" (at least it does so for
certain values of X, although not for all). But it does not allow you to
handle "X is true of A and Y is true of B". Ergo you need something in
addition. In Kal's view: TMCL.


Steve Pepper <pepper@ontopia.net>
Chief Strategy Officer, Ontopia
Convenor, ISO/IEC JTC 1/SC 34/WG 3
Editor, XTM (XML Topic Maps 1.0)