FUML12 — AcceptEventActionActivation::match should match instances of descendants of a trigger's signal

Specification: Semantics of a Foundational Subset for Executable UML Models (FUML), v1.1 (formal-13-08-06)
Subclause: 8.6.4.2.1 AcceptEventActionActivation

The AcceptEventActionActivation::match operation should not require equality of Signals to match a signal instance to the Signal of a trigger of the AcceptEventAction. Rather, it should allow the Signal of the signal instance to be a descendant of the Signal of a trigger SignalEvent.

Change AcceptEventActionActivation::match

The UML 2.4.1 specification is not explicit on how the receipt of a signal is matched to a signal event. The UML 2.5 specification, however, in 13.3.3, states that "A SignalEvent is a MessageEvent for messages requesting the reception of an instance of a specific Signal." Since an instance of a specialization of a signal is also an instance of the general signal, the statement in the UML 2.5 specification supports the view that the intent is that instances of specialized signals also match a signal event for the general signal.