SBVR12 — Urgent issue on SBVR 1.1 RTF (NOT SBVR 1.2)

Section 13.2.5 is based on a misunderstanding and misuse of MOF:

a) the phrase “In each case where an attribute and an association end represent the same role, the SBVR Metamodel includes a tag that tags both the attribute and the association end. “ is in ignorance of the fact that in MOF2 and UML 2 that “attributes” and “association ends” are both represented as instances of Property: and in such a case there would be a single instance of Property linked to the Class using the attribute meta-property and from the Association by the memberEnd (or ownedEnd) property: eliminating the need to link two separate elements.

b) attempting to use MOF Tags to link two properties. In fact MOF Tags are “Simple string name-value pairs”.

This is an urgent issue since it affects the production of the SBVR 1.1 artifacts: there is in fact no need for the tags that have caused some of the difficulties producing the machine-readable files: even the file I sent today for the metamodel, which uses the Tag value property does not match this section of the spec which states that value is the empty string.

1. Item a) in Issue statement:

As per SBVR Clause 13, the class attribute element in the sameRole MOF Tag represents a different Property from the Property referenced by the association end element in the sameRole MOF Tag – not the same Property as asserted in the Issue statement. The semantics of using the two different properties is different in that one is used to identify a complete (closed-world) extension of a verb concept role with respect to a given subject, but the other is used to identify individual instances of the role with an open-world assumption.

There is no change required for this part of the Issue statement.
2. Item b) in Issue statement.

The resolution to this part of the Issue statement is to drop the sameRole MOF Tags from the SBVR Metamodel file as they are an invalid use of MOF Tags.
3. Paragraph 2 of the Issue Statement

Dropping the sameRole MOF Tags from the SBVR Metamodel file resolves the points in this paragraph of the Issue statement.