The model we have developed has many Instance Specifications with specific values.

In Generic Tables and Instance Tables, we have columns that we populated using some often quite complex Structured Expressions (often encapsulated in whole or in part in Opaque Behaviors).

It occurred to me that in principle these queries could be more manageable if we created each as a Derived Property rather than as a Custom Column. (Then we could reference a derived property in multiple tables, or, better yet, even with a more complex query.) It is easy to create a Derived Property instead of a Custom Column, but the resulting Derived Property, for instance, is owned by and applied to a generic Instance Specification metaclass, so it shows up as an available option for any Instance Specification, regardless of its Classifier, which is not at all what we want.

Notes:

A Derived Property created in the dialog for a Classifier of the Instance Specification (or at least a Base Classifier of that) is not selectable in an Instance Table for an Instance Specification of that Classifier. In fact, the Derived Property is a customization of the generic Block in our case.

A Derived Property is owned by a Metaclass or Stereotype. I'm not sure how it would be possible, let alone practical, to define a Stereotype or Metaclass for an Instance Specification that was an instance of a Block within a certain family.

I think maybe I am missing something.

Is there a way to store a derived value that a table or a query can reference, at an appropriate level?