[topicmapmail] LTM 1.3 Change Proposal

[Murray Altheim]

Lars Marius Garshol wrote:
> Ontopia published a proposal for LTM 1.3 in 2002, but didn't do
> anything further with it, despite a number of requests from various
> directions. We've now decided to try to do LTM 1.3 as soon as
> possible, and to this end I've updated the change proposal to reflect
> our latest thoughts on this.
> 
> It can be found at
> 
> <URL: http://www.ontopia.net/topicmaps/materials/ltm-1.3-prop-2.html >
> 
> and comments to it are more than welcome.

Lars Marius,

In XTM 1.0 we specified both class-instance and superclass-subclass
associations. With the XTM shorthand of <instanceOf> we had the ready
ability to express Topic types, and this showed up in LTM as the colon
(':') following a Topic ID.

    [john : human]

meaning 'john' is an instance of the class 'human'.

With the release of Ceryle recently the presence of its variant
syntax on LTM 1.2 might be noted as a proposal for 1.3 (I think
I've mentioned this one before). It's a simple additional shorthand
to mirror the colon (':') character, only to perform this for the
XTM 1.0 superclass-subclass association using a semicolon (';')
character, e.g.:

    [human ; mammal]

meaning 'human' is a subclass of the superclass 'mammal'.

I certainly didn't have any difficulty implementing this in Ceryle,
and the shorthand is used very extensively in Ceryle's Topic Map
(LTM sourced) ontologies, which include predominantly a class
hierarchy. Absent the ';' shorthand it would have made my LTM files
considerably more complicated, and I would propose the semicolon
be added to LTM 1.3's syntax. I would then endeavour to match the
LTM 1.3 syntax in Ceryle rather than having a variant. I frankly
wouldn't give up the semicolon since it is so valuable in my own
LTM files.

Thanks for your consideration,

Murray

......................................................................
Murray Altheim                    http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK               .

                  Empty handed, holding a hoe,
                  Walking, riding a water buffalo,
                  A man is crossing over a bridge;
                  The bridge, not the water, flows.

                         -- Mahasattva Fu, The Blue Cliff Record [96]