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  1. OMG Issue

UMLR — Description of Generalization of Enumerations is contradictory

  • Key: UMLR-750
  • Status: open  
  • Source: oose Innovative Informatik eG ( Axel Scheithauer)
  • Summary:

    The specification says:

    An instance of a Classifier is also an (indirect) instance of each of its generalizations.

    This means that the run-time extension of a general Classifier includes the extension of the specific Classifier: All instances of Rectangle are also instances of Polygon.
    Now it says about Enumeration:

    An EnumerationLiteral defines an element of the run-time extension of an Enumeration.

    Taken together this means that all EnumerationLiterals of a specific Enumeration (its run-time extension) must also be contained in the set of Literals of the general Enumeration.
    Finally it says about Enumeration specialization:

    An Enumeration that specializes another may define new EnumerationLiterals that are not defined in the generalizing Enumeration.

    This is a contradiction. The extension of a specific Classifier must always be smaller than that of the general Classifier.
    I agree that this makes the specialization of Enumerations unusable for a lot of purposes. However I don't see how this could get changed.

  • Reported: UML 2.5 — Tue, 8 May 2018 14:07 GMT
  • Updated: Wed, 13 Mar 2019 06:40 GMT
  • Attachments: