[trans] - Model comments

[David Berry]

Hi Gerard,

On Wed, 11 Mar 2020 at 12:37, Gerard Lemson <glemson1 at jhu.edu> wrote:

> The model you use is illegal in terms of VO-DML. A composition relation is a parent-child relation where a parent MUST exist before a child can be added. In your model CompoundMapping is-a Mapping, but is also its parent in a parent-child relationship.
> Instead a compound type like this is generally built according to the pattern in the attached diagram.
> Note that the associative class also allows more metadata to be added such as the role the referenced object plays, or in this case the rank of the object in the collection.
>
> I agree with your thoughts on forward-inverse.

So would the attached model be legal? This is a combination of my
original model with the technique you (and also Mark in a private
email from last week) illustrated. My own hope is for a model in which
everything is a Mapping (except for the MapRef class). So you can use
a compound mapping of any type where-ever you can use an atomic
mapping, and vice-versa.

David
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