UMLR — Clarifying the support for and semantics of subsetting/redefinition for a pair of properties defined in different contex

Currently, the prevalent use of property subsetting/redefinition mechanism has been confined to a pairs of properties defined within a single artifact (e.g., metamodel, user model, ....) In principle, the specification allows using this mechanism even for a pair of properties where the subsetted/redefined property is defined in one artifact (e.g., a metamodel) and the subsetting/redefining property is defined in another artifact (e.g., a profile extending the metamodel). This flexibility could be useful in practice – e.g., see some of the proposed changes for SysML1.3 here: http://www.omg.org/members/sysml-rtf-wiki/doku.php?id=rtf3:groups:9_ports_and_flows.

The specification does not explicitly discuss what is the semantics of subsetting/redefinition when the subsetted/redefined property is in a different artifact, potentially at a different level than the artifact where the subsetting/redefining property is defined.

Combinations of subsetted/redefined property vs. subsetting/redefining property could include:

• metamodel/profile
• profile/profile
• library/profile