UML22 — Section: Common Behavior

Second paragraph of Semantics section of Trigger in Common Behavior is inconsistent with the first paragraph of p 605 in semantics of State. The semantics of Trigger does not accomodate deferred events.

The noted paragraph in Trigger is not actually in conflict with deferred events. The semantics of Trigger states that once "an event is dispatched" it is "considered consumed" and is then "no longer available for processing". However, the semantics for deferred event under State says that "an event that does not trigger any transitions in the current state, will not be dispatched" if it is deferred. Therefore, there is no conflict with it being consumed only if it is actually dispatched.
However, it would probably be helpful to clarify this under Trigger. Also, the semantic variation point on discarding an event if there is no appropriate trigger is not correct, since, for a transition even, at least, if the event is deferred it is not discarded, and if it is not deferred it is.