This goes into the definition of "close over." I could not find the formal definition and it seems our understandings may be slightly different. Perhaps we should stick the definition in the Akka documentation (apologies if it is already there and I just happen to miss out).

My understanding of close over in the context of an actor is as follows: "Access to the actor state from a closure that may be executed from another thread." It seems inaccurate based on what you're saying.

I'll change it as suggested.