[sc34wg3] Questions on N0396: (2) one or more association memberships

Steve Pepper sc34wg3@isotopicmaps.org
Sat, 19 Apr 2003 16:21:06 +0200

At 17:39 18.04.2003 +0200, Lars Marius Garshol wrote:
>This is a carry-over from HyTM and XTM, both of which allow unary
>associations. The rationale, I've been told, was that unary
>associations are essentially assertions about a single subject, such
>   is-inquisitive(jan : person)
>SAM has to have this because HyTM and XTM have it.
>| I suggest to constrain the cardinality of the [roles] property of an
>| association item to be two or more.
>No can do, since that would break backwards compatibility.
>I'm pretty sure I've seen people use this in actual topic maps, though
>I forget where.

One version of the opera topic map had this:

    unfinished( turandot : opera )

i.e. an association of type 'unfinished' with one role player,

Was this the example you were thinking of?


Steve Pepper, Ontopian