EXPRESS 1.1 RTF Avatar
  1. OMG Issue

EXPRESS11 — replace {disjoint, total} in diagrams with generalization sets

  • Key: EXPRESS11-6
  • Legacy Issue Number: 19027
  • Status: closed  
  • Source: Thematix Partners LLC ( Edward Barkmeyer)
  • Summary:

    Several UML diagrams in the EXPRESS metamodel bear the markup

    {disjoint, total}

    over class-subclass decompositions. This markup is not documented in the text of the specification, and the implied generalization sets are not present in the MOF metamodel. The preferable solution is to create the generalization sets with the isDisjoint and isCovering features of MOF2.4. An alternative solution is to remove the text from the diagrams.

  • Reported: EXPRESS 1.0 — Thu, 24 Oct 2013 04:00 GMT
  • Disposition: Resolved — EXPRESS 1.1
  • Disposition Summary:

    To improve the quality of the model, the RTF determined to create the GeneralizationSets that carry the intent of the markup, which was the default interpretation in UML v1.4 (the original source of the model). This requires changing many diagrams in only this way, and properly documenting the GeneralizationSets.
    None of the generalization sets introduced in this revision are conceptually new – they all reflect restrictions defined by ISO 10303-11. Therefore the formalization should not affect implementations. The RTF regards these changes as improvements in the quality of the MOF model, not in its content.
    There is an error in Figure 10.1, which says that the Instance categories are disjoint, although the diagram shows an overlapping subclass. This error is corrected in the metamodel (below), but the diagram is substantively modified by another Issue resolution.
    The creation of certain generalization sets combines generalizations from different packages, and thus causes some package imports to become merges. The text of those sections is modified by Issue 19028, and is not corrected here.

  • Updated: Mon, 9 Mar 2015 14:34 GMT