Issue 6200: UML 2 Super/Metamodel/redefinition and substitutability (uml2-rtf) Source: Simula Research Laboratory (Mr. Bran Selic, selic(at)acm.org) Nature: Uncategorized Issue Severity: Summary: Redefinition, as used in UML2, sometimes violates superclass substituitability rules. For example, redefining multiplicity from many to 1 breaks some OCL constraints. For example, Statemachines changed a multiplicity from many to 1. Statemachines redefines association to OwnedBehaviors to OwnedStateMachines which does not allow other types of owned behaviors. Resolution: Discussion The specific issue with state machines no longer applies, having been resolved in an earlier RTF. The general issue about redefinition is a complaint about a fundamental characteristic of UML semantics which are by now quite well understood. Changing these semantics would be very fundamental and disruptive. This also resolves issue 14929. Disposition: Closed - No Change Revised Text: Actions taken: September 7, 2003: received issue February 20, 2015: closed issue Discussion: Indeed. However, this is a serious and contentious theoretical issue and it’s resolution is beyond the scope of the FTF. Fortunately, the specific issue with state machines has been eliminated by the resolution to issue 6185. Due to lack of time, the RTF/FTF agrees that the following are problems that need fixing, but decided to defer their resolution to a future RTF working on this specification. End of Annotations:===== To: issues@omg.org Subject: UML 2 Super/Metamodel/redefinition and substitutability X-Mailer: Lotus Notes Release 5.0.11 July 24, 2002 From: Branislav Selic Date: Sun, 7 Sep 2003 09:15:24 -0400 X-MIMETrack: Serialize by Router on D25ML05/25/M/IBM(Release 6.0.2CF1|June 9, 2003) at 09/07/2003 09:15:26, Serialize complete at 09/07/2003 09:15:26 Redefinition, as used in UML2, sometimes violates superclass substituitability rules. For example, redefining multiplicity from many to 1 breaks some OCL constraints. For example, Statemachines changed a multiplicity from many to 1. Statemachines redefines association to OwnedBehaviors to OwnedStateMachines which does not allow other types of owned behaviors. Bran Selic IBM Software Group -- Rational Software 770 Palladium Drive Kanata, Ontario, Canada K2V 1C8 ph. (613) 591-7915 fax (613) 599-3912 e-mail: bselic@ca.ibm.com