Issue 6878: UML 2 Infrastructure / rule for redefinition of Property (uml2-rtf)
Source: Simula Research Laboratory (Mr. Bran Selic, selic(at)acm.org)
Nature: Uncategorized Issue
Severity: 
Summary: The isConsistentWith() query defined on Property implies that in order for a property redefinition to be logically consistent, the redefining property must be derived if the redefined property is derived. Are these the correct semantics for redefinition? There are cases in the metamodel where this constraint is violated (e.g. Package::ownedMember is not derived, but it redefines derived property Namespace::ownedMember). If there is to be a constraint on redefinition, perhaps it makes more sense the other way around, i.e. a redefining property must be non-derived if the redefined property is non-derived. 

Resolution: 
Revised Text: 
Actions taken:
January 2, 2004: received issue
February 18, 2005: moved from infrastructure
Discussion: 
Disposition:	Deferred to UML 2.4 RTF
End of Annotations:=====
ubject: UML 2 Infrastructure / rule for redefinition of Property 
X-Mailer: Lotus Notes Release 6.0.2CF1 June 9, 2003 
From: Branislav Selic <bselic@ca.ibm.com> 
Date: Fri, 2 Jan 2004 07:44:20 -0500 
X-MIMETrack: Serialize by Router on D25ML05/25/M/IBM(Release 6.0.2CF1|June 9, 2003) at 
 01/02/2004 07:44:22, 
        Serialize complete at 01/02/2004 07:44:22 


The isConsistentWith() query defined on Property implies that in order for a property redefinition to be logically consistent, the redefining property must be derived if the redefined property is derived. Are these the correct semantics for redefinition? There are cases in the metamodel where this constraint is violated (e.g. Package::ownedMember is not derived, but it redefines derived property Namespace::ownedMember). If there is to be a constraint on redefinition, perhaps it makes more sense the other way around, i.e. a redefining property must be non-derived if the redefined property is non-derived. 

Bran Selic
Distinguished Engineer
IBM Rational Software