[sc34wg3] New syntax for (binary) associations

[Dmitry]

On 31-Jan-08, at 1:51 PM, Steve Pepper wrote:

> I want to make sure I understand this proposal correctly:
>
> * Lars Heuer
> |
> | > The idea to create binary assocs with predefined role types
> | > (subject, object) is sexy, but I wonder if this is the right
> | > thing for CTM.
>
> Question: Would every association of every type that uses this
> proposed syntax end up with the two predefined role types
> 'subject' and 'object'? In other words:
>
>    born-in( subject puccini, object lucca )
>    composed-by( subject tosca, object puccini )
>    located-in( subject lucca, object tuscany )
>    etc.
>
> If so, this is definitely NOT something for CTM because it
> involves creating a syntax for a design pattern that no-one has
> ever used before (at least as far as I know). I'm not
> necessarily against creating syntactic shortcuts for design
> patterns that are well-established, but this certainly ain't one
> of them ;-)
>


Another idea about standard roles tm:subject and tm:object:

It is possible to use a concept of a "domain" to represent  
specialized relationships.

For example, instead of saying

borders(country: USA, country: Canada)

it is possible to say

geo:borders(tm:subject: USA, tm:subject: Canada) or simply -   
geo:borders(USA & Canada)

With standard roles, we also can define "clean"  type-subtype  
relationships between associations:

sumo:borders
     isa o:SymmetricAssociation
.

geo:borders
     ako    sumo:borders;
     tc:has_role [
        tc:range geo:Country
     ]
.

math:borders
     ako    sumo:borders
     tc:has_role [
        tc:range math:Figure
     ]
.

Dmitry