UMLR — authorize a reference to an operation in a realized interface.

A common task is to implement the operations of an interface I in a class A. The implementation of an operation has a specification reference to the realized operation. In the current UML specification, the operation must be copied into the class before it can be realized, since only owned behavioral features can be referenced: "(section 13.3.2) ... The behavioral feature must be owned by the classifier that owns the behavior or be inherited by it.". I.e. the standard only allows to reference inherited operations, but not realized operations. This is not very practical, since it implies not only copying the operation but also assuring that it remains synchronized with the operation that is defined in the interface (of course, the modeling tool could do the synchronization, but it would still imply storing redundant information within the model). It would be good to authorize a reference to an operation in a realized interface.