a) Technically TFA never mentions the word "actor" so your mincing such fine meat regarding the exact wording of definitions in actors is utterly irrelevant. b

a) Technically TFA never mentions the word "actor" so your mincing such fine meat regarding the exact wording of definitions in actors is utterly irrelevant. b) sender / "customer" / whatever. Whoever gets marked as the "receiver of results". From TFA: "I've already taken that and generalised it to mean "send result", using it in filter definitions, where "^" means "send a result to the next filter in the pipeline"